• Journal of IKEEE
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• v.25 no.4
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• pp.598-606
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• 2021

In this paper, we presents a new service binding and resource management model for context based services in mobile edge computing (MEC) networks. The proposed control is composed of two layers: MEC service bindng control layer (MCL) and user context control layer (UCL). The MCL manages service binding construction, resource allocation, and service policy construction from a system point of view; and the UCL manages real-time service adaptation using meta-objects. Through simulations, we confirmed that the proposed control offers enhanced throughput and content transfer time when it is compared to the legacy computing and control models. The proposed control model can be employed as a key component for the context based various internet-of-things (IoT) services in MEC environments.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.465-477
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• 2023

In proton exchange membrane fuel cell (PEMFC), proper thermal management of the stack and moisture generation by electrochemical reactions significantly affect fuel cell performance. In this study, the PEMFC dynamic characteristic model was developed through Simcenter AMESim, a development program. In addition, the developed model aims to understand the thermal resin balance of the stack and performance characteristics for input loads. The developed model applies the thermal management model of the stack and the moisture content and permeability model to simulate voltage loss and stack thermal behavior precisely. This study extended the C based AMESet (adaptive modeling environment submodeling tool) to simulate electrochemical reactions inside the stack. Fuel cell model of AMESet was liberalized with AMESim and then integrated with the balance of plant (BOP) model and analyzed. And It is intended to be used in component design through BOP analysis. The resistance loss of the stack and thermal behavior characteristics were predicted, and the impact of stack performance and efficiency was evaluated.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.303-313
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• 2018

In order to provide quality services across international airports, airline personnel must rapidly and effectively develop and share knowledge. Combining components of adaptive structuration theory (AST) and media synchronicity theory (MST), a research framework was developed to convey three distinct stages of knowledge sharing. We use the grounded theory research method for the qualitative data collected from audio transcripts of employees learning how to use and work with company issued smartphones with push-to-talk functionalities. Data was collected from 33 operations personnel. The results of the content analysis are recorded for the elements of each of the three concepts of our research framework. During the social interaction stage, the content of the audio conversations shifts mainly from conflict management to task management; for media synchronicity, from quality to quantity; for productive outcomes, from efficiency to commitment. New insights are uncovered from our analysis of data from the field as users advance from learning how to use the mobile devices, to using the devices for managing knowledge for their work in the airline industry.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.4 s.304
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• pp.95-102
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• 2005

In this paper, we propose a user friendly object-based image retrieval system using the interaction between cortex and hippocampus. Most existing ways of queries in content-based image retrieval rely on query by example or query by sketch. But these methods of queries are not adequate to needs of people's various queries because they are not easy for people to use and restrict. We propose a method of automatic color object extraction using CSB tree map(Color and Spatial based Binary をn map). Extracted objects were transformed to bit stream representing information such as color, size and location by region labelling algorithm and they are learned by the hippocampal neural network using the interplay between cortex and hippocampus. The cells of exciting at peculiar features in brain generate the special sign when people recognize some patterns. The existing neural networks treat each attribute of features evenly. Proposed hippocampal neural network makes an adaptive fast content-based image retrieval system using excitatory learning method that forwards important features to long-term memories and inhibitory teaming method that forwards unimportant features to short-term memories controlled by impression.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.839-846
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• 2006

Context-aware adaptive service for overcoming the limitations of wireless devices and maintaining adequate service levels in changing environments is becoming an important issue. However, most existing studies concentrate on an adaptation module on the client, proxy, or server. These existing studies thus suffer from the problem of having the workload concentrated on a single system when the number of users increases md, and as a result, increases the response time to a user's request. Therefore, in this paper the adaptation module is dispersed and arranged over the client, proxy, and server. The module monitors the contort of the system and creates a proposition as to the dispersed adaptation system in which the most adequate system for conducting operations. Through this method faster adaptation work will be made possible even when the numbers of users increase, and more stable system operation is made possible as the workload is divided. In order to evaluate the proposed system, a prototype is constructed and dispersed operations are tested using multimedia based learning content, simulating server overload and compared the response times and system stability with the existing server based adaptation method. The effectiveness of the system is confirmed through this results.

• The KIPS Transactions:PartB
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• v.14B no.5
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• pp.321-328
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• 2007

In this paper, we propose a fast and dynamic Region-of-Interest coding method using the adaptive code-block discrimination algorithm in JPEG2000 images which complements the implicit ROI coding method and the modified implicit ROI coding method. For reducing the time of discriminating the code block, the proposed method estimates the characteristics of the shape of ROI and makes the shape of boundaries, and classifies the patterns of each code block. The method improves the preferred processing and loss of wavelet coefficients of background within the ROI code blocks by adaptively classifying the code blocks with the percentage of content of the wavelet coefficients using the thresholds of ROI and background. Also, the priority control of wavelet coefficients of background within ROI code block supports the rapid ROI coding by processing in batch based on patterns unlike the existing methods that process with unit of wavelet coefficients. To show the usefulness of this method, we compared this to the existing methods. There is no difference in performance, but we confirmed very speedy in processing time.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.411-418
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• 2014

Vascular remodelling is an adaptive mechanism, which counteracts pressure changes in blood circulation. Nicotine content in cigarette increases the risk of hypertension. The exact relationship between nicotine and vascular remodelling still remain unknown. Current study was aimed to determine the effect of clinically relevant dosage of nicotine (equivalent to light smoker) on aortic reactivity, oxidative stress markers and histomorphological changes. Twelve age-matched male Sprague-Dawley rats were randomly divided into two groups, i.e.: normal saline as control or 0.6 mg/kg nicotine for 28 days (i.p., n=6 per group). On day-29, the rats were sacrificed and the thoracic aorta was dissected immediately for further studies. Mean arterial pressure (MAP) and pulse pressure (PP) of nicotine-treated vs. control were significantly increased (p<0.05). Nicotine-treated group showed significant (p<0.05) increase tunica media thickness, and decrease in lumen diameter, suggesting vascular remodelling which lead to prior hypertension state. The phenylephrine (PE)-induced contractile response in nicotine group was significantly higher than control group ($ED_{50}=1.44{\times}10^5M$ vs. $4.9{\times}10^6M$) (p<0.05~0.001). However, nicotine-treated rat showed significantly lower endothelium-dependent relaxation response to acetylcholine (ACh) than in control group ($ED_{50}=6.17{\times}10^7M$ vs. $2.82{\times}10^7M$) (p<0.05), indicating loss of primary vascular function. Malondialdehyde (MDA), a lipid peroxidation marker was significantly higher in nicotine group. Superoxide dismutase (SOD) enzymatic activity and glutathione (GSH) were all reduced in nicotine group (p<0.05) vs. control, suggesting nicotine induces oxidative imbalance. In short, chronic nicotine administration impaired aortic reactivity, probably via redox imbalance and vascular remodelling mechanism.

• Science of Emotion and Sensibility
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• v.9 no.spc3
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• pp.179-185
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• 2006

This study examines and compares various recommendation techniques which have been used successfully in other fields and seeks for opportunity to improve design personalization service more effectively. Throughout the literature study, several major recommendation techniques were identified, namely 'contents-based filtering', 'collaborative filtering', and 'demographic filtering'. In order for finding out relative advantages and disadvantages, a case study was carried out by applying different techniques. The result showed that in general, demographic filtering was evaluated least efficient among the techniques. Content-based filtering showed the best efficiency among them. Another significant finding was that the collaborative filtering had a better efficiency as the number of test subjects is increased. In conclusion, we suggest that design recommendation services can be improved by applying contents-based or collaborative filtering for better efficiency of recommendation. And, if the number of test subjects is large enough, it may be possible to remarkably improve the efficiency of design recommendation services by using collaborative filtering.

• Journal of Korea Multimedia Society
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• v.17 no.1
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• pp.26-33
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• 2014

Video retrieval and indexing are performed by comparing feature similarities between key frames in shot after detecting a scene change and extracting key frames from the shot. Typical image features such as color, shape, and texture are used in content-based video and image retrieval. Many approaches for integrating these features have been studied. However, the issue of these approaches is how to appropriately assign weighting of key frame features at query time. Therefore, we propose a new video retrieval method using adaptively weighted image features. We performed computer simulations in test databases which consist of various kinds of key frames. The experimental results show that the proposed method has better performance than previous works in respect to several performance evaluations such as precision vs. recall, retrieval efficiency, and ranking measure.

• Journal of The Korean Association of Information Education
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• v.20 no.2
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• pp.189-196
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• 2016

The PATROL instructional model only uses digital textbooks. PATROL is an acronym for Planning, Action, Tracking, Recommending, Ordering, and Leading. Teachers have a difficult time using current digital textbooks to determine how much time students spend using course materials. This is because current digital textbooks can only show the content of paper textbooks and display additional multimedia materials. In this study, digital textbook functions were designed based on the PATROL model in order to analyze students' learning situations, diagnose problems, and offer solutions. Digital textbook are based on learning analytics named SEE-PAD. SEE-PAD is composed of the following: Social network analysis; Evaluation and assEssment analysis; Predictive analysis; Adaptive learning analysis; and the analysis Dashboard. I drew and showed the use case and sequence diagrams of SEE-PAD to help design digital textbook functions.