• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.512-514
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• 1998

The paper presents a model reference adaptive control containing a fuzzy algorithm for tuning the gain coefficient which adjusts the level of the fuzzy controller output. The synthesis of a fuzzy tuning algorithm has been performed for the inverted pendulum system. The computer simulation results have proved the efficiency of the proposed method, showing stable system responses.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1101-1110
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• 2008

The present paper investigates about the formation of the logical thinking and the intuitive thinking in mathematical concepts with reference to secondary talented students (students aged 16$\sim$17 years). As a main result, we conclude that their preference between the logical and the intuitive thinking does not related to the distinction of the school level and sex, while their consistence between them relates.

• 한국노년학
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• v.39 no.1
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• pp.169-188
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• 2019

In this study, the author utilizes longitudinal data of the recent 12 years to verify whether the absolute versus relative income of old age has a significant effect on their life satisfaction of life. The findings of this study show that there is a significant difference in life satisfaction of old age according to respondents' relative income of three reference groups based on their asset quintile and residental area and education. In the correlation analysis using the cross-sectional data, the absolute and relative income level was closely related to the life satisfaction. In the panel regression analysis using the 12 years longitudinal data from the Korea National Labour Panel dataset, the income level of counterparts in those reference groups appeared highly significant in determining the level of life satisfaction of the elderly. However, some demographic variables such as age and marital status did not have a statistically significant effect in the long-term perspective. The income of reference groups in terms of asset levels, education and region as well as their own past life satisfaction level had a significant effect on the elders' life satisfaction determination. These results suggest that the relative income hypothesis in terms of life satisfaction among the elderly is more valid than the previous absolute income hypothesis.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.11 no.4
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• pp.229-237
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• 2011

As smart phones have become widely adopted, they have brought about changes in individual lifestyles, as well as significant changes in the industry. As the mobile technology of smart phones has become associated with all areas of industry, it is not only accelerating innovation in other industries such as shopping, healthcare service, education, and finance, but is also creating new markets and business opportunities. The preparation of thorough security measures for smart phones is increasing in demand. While offering excellent mobility and convenience, smart phones can be exposed to a range of violation threats. In particular, it is necessary to make efforts to develop a security system that can preemptively cope with potential security threats in the banking service area, which requires a high level of reliability. This paper suggests a security reference model that is considered for the smart phone-based joint mobile banking development project being undertaken by the Bank of Korea in 2010. The purpose of this study is to make a security reference model for a reliable smart phone-based mobile financial service, by recognizing the specific security threats directed toward smart phones, and providing countermeasures to these security threats. The proposed mobile banking security reference model is useful in improving system security by systematically analyzing information security threats to the mobile financial service, and by presenting the guideline for the preparation of countermeasures.

• Journal of the Korean Society for information Management
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• v.24 no.2
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• pp.105-122
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• 2007

To understand the present status and the development of the digital reference service in Korean public libraries, a nationwide site observation was attempted in 2007. The collected data was analyzed, then compared with the previous analysis based on a 2003 data. For the 404 sites offering digital reference, operational characteristics, such as access level, service mode, link description, policy, web form, and FAQ, are analyzed, Performance analysis focused on the presence of question posting, volume of usage, response rate, and types of the questions, for the data collected for 15 days through question and answer transcript recording. Results reveal findings on the present situation as well as changes over 4 years. Related problems are identified. The conclusion includes suggestions for improving digital reference service.

• Korean Journal of Child Studies
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• v.33 no.5
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• pp.53-70
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• 2012

The purpose of this study was to investigate the effects of task conditions (physical similarity between the spatial product and the reference space, presentation place of the spatial product) on children's spatial representation. The participants consisted of 40 3-year-olds and 40 4-year-olds. The results of this study are as follows. Both 3-year-olds and 4-year-olds were capable of a greater degree of spatial representation when there was a high level of physical similarity between the spatial product and the reference space, and when the presentation place of the spatial product was in the reference space. 4-year-olds were capable of more accurate spatial representation than 3-year-olds. There was no significant difference in the children's spatial representation depending on the type of spatial product (scale model, map). The results revealed that the physical similarity between the spatial product and the reference space and the presentation place of the spatial product are essential in young children's spatial representation. Additionally, the results indicated that spatial representation of children develops gradually from when they are three to when they turn four.

• ETRI Journal
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• v.39 no.1
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• pp.97-107
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• 2017

A fast and accurate building-level visual place recognition method built on an image-retrieval scheme using street-view images is proposed. Reference images generated from street-view images usually depict multiple buildings and confusing regions, such as roads, sky, and vehicles, which degrades retrieval accuracy and causes matching ambiguity. The proposed practical database refinement method uses informative reference image and keypoint selection. For database refinement, the method uses a spatial layout of the buildings in the reference image, specifically a building-identification mask image, which is obtained from a prebuilt three-dimensional model of the site. A global-positioning-system-aware retrieval structure is incorporated in it. To evaluate the method, we constructed a dataset over an area of $0.26km^2$. It was comprised of 38,700 reference images and corresponding building-identification mask images. The proposed method removed 25% of the database images using informative reference image selection. It achieved 85.6% recall of the top five candidates in 1.25 s of full processing. The method thus achieved high accuracy at a low computational complexity.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.302-308
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• 2011

The aim of this study is to compare reference levels for radiation dose in angiography and interventional radiology. Proposed reference levels for various procedures and classification of diseases are provided by fluoroscopy time and kerma area product(KAP) rate normalizing the body habitus focusing the cerebrum. Subarachnoid hemorrhage(SAH) represents the highest KAP-rates and aneurysm represents the lowest KAP-rates. According to these types of procedures, internal carotid artery(ICA), common carotid artery(CCA), and vertebral artery(VA) show the highest KAP-rates and guglielmi detachable coil shows the lowest KAP-rates. Therefore, the present study can suggested reference levels for patient radiation dose and is expected to be further useful in the field of radiation dose education and management of angiography and interventional radiology.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.859-864
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• 2007

In the future, it is necessary that using the Satellite-based radio navigation augmentation system such as Differential Global Positioning System(DGPS) to achieve a position accuracy of sub-meter level in port. Generally, the receiver for DGPS reference station should meet performance specifications of RSIM Ver. 1.1 presented by RTCM. This paper proposes a method to verify performance of the receiver for DGPS reference station according to the RSIM Ver. 1.1. And this paper presented that performance evaluation of the commercial receiver for DGPS reference station through the proposed method is satisfied with RSIM Ver. 1.1.

• Industrial Engineering and Management Systems
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• v.11 no.1
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• pp.30-38
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• 2012

This paper discusses a clearance pricing on daily perishable products considering a reference price of consumers. The daily perishable products are sometimes sold at a discount price before closing time to stimulate demand when the number of unsold products is more than initially envisioned. The discount pricing results both in an increase of the revenue of the day and in a decrease of the disposal cost. The discounting, however, also declines a reference price of consumers which is a mental price and serves as an anchor price to judge if a current sales price is loss or gain for the consumers. An excess discounting decreases the demand for the products sold at a regular price in the future and diminishes long-term profit. This study conducts a mathematical analysis on the clearance pricing problem for a single period with stochastic variations both on demand and on the inventory level at clearance time. The expected profit function especially depends on the response of consumers to the clearing price against their reference prices. A procedure is proposed to derive an optimal clearance price when consumers are loss-neutral. A sufficient condition is shown to obtain an optimal price for loss-averse and loss-seeking consumers by an analogous procedure.