• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.297-301
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• 2001

In this paper, a system that transmits ECG signals which get from hand baggage ECG is implemented by using Bluetooth technology. Bluetooth technology is a close range wireless communication used wireless frequency 2.4GHz bandwidth. This technology consumes very small power and provides high reliability also self error correction with high speed frequency hopping. Because every device which uses Bluetooth protocol can communicate each other. These can connect between the system implemented and any devices such as mobile telephone with Bluetooth module, notebook, and the personal mobile device. Also, the paper proposes capability of transmission to the sever of hospital through each type of wireless communication device that acquired medical information signals in mobile medical machine. The system consists of hardware parts with Bluetooth module and host part, and software parts with blutooth protocol stacks. The host precesses a connection with other device and transmits ECG signals with bluetooth frequency hopping sequence.

• Journal of Information Processing Systems
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• v.8 no.2
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• pp.213-240
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• 2012

Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test ma Safety critic Safety critical systems, real time systems, and event-based systems have a complex set of events and their own interdependency, which makes them difficult to test manually. In order to cut down on costs, save time, and increase reliability, the model based testing approach is the best solution. Such an approach does not require applications or codes prior to generating test cases, so it leads to the early detection of faults, which helps in reducing the development time. Several model-based testing approaches have used different UML models but very few works have been reported to show the generation of test cases that use events. Test cases that use events are an apt choice for these types of systems. However, these works have considered events that happen at a user interface level in a system while other events that happen in a system are not considered. Such works have limited applications in testing the GUI of a system. In this paper, a novel model-based testing approach is presented using business events, state events, and control events that have been captured directly from requirement specifications. The proposed approach documents events in event templates and then builds an event-flow model and a fault model for a system. Test coverage criterion and an algorithm are designed using these models to generate event sequence based test scenarios and test cases. Unlike other event based approaches, our approach is able to detect the proposed faults in a system. A prototype tool is developed to automate and evaluate the applicability of the entire process. Results have shown that the proposed approach and supportive tool is able to successfully derive test scenarios and test cases from the requirement specifications of safety critical systems, real time systems, and event based systems.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.10
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• pp.413-420
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• 2013

Redundant arrays of independent disks (RAID) without a power-fail-safe component in small and mid-sized business suffers from intolerably long resynchronization time after a unclean power-failure. Data blocks and a parity block in a stripe must be updated in a consistent manner, however a data block may be updated but the corresponding parity block may not be updated when a power goes off. Such a partially modified stripe must be updated with a correct parity block. However, it is difficult to find which stripe is partially updated (inconsistent). The widely-used traditional parity resynchronization manner is a intolerably long process that scans the entire volume to find and fix inconsistent stripes. This paper presents a fast resynchronization scheme with a negligible overhead for small and mid-sized RAIDs. The proposed scheme is integrated into a software RAID driver in a Linux system. According to the performance evaluation, the proposed scheme shortens the resynchronization process from 200 minutes to 5 seconds with 2% overhead for normal I/Os.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.225-233
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• 2015

The convergence social app manufacturing platform for both demander and developer in worldwide provides a collective collaborative development approach. This platform can bring enhanced productivity with exchange of views among participants. If the assessment is not fair that many participants will leave the collective collaborative project. The previous studies verified the reliability of the evaluation based on statistical techniques. Because the previous studies did not consider the task performance of participants, do not reflect the feature of project tasks. So, the contribution scores of the participants can be distorted. In this study, we suggest the method for evaluating the development contributions value. This is considered the task performance of participants and involved the method of equitable and consistency peer assessment.

• Journal of the Korean Society of Costume
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• v.57 no.7
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• pp.1-14
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• 2007

This study investigates the differences between the satisfaction factors of store characteristics depending on on-line clothing store type and its satisfaction index. The collected data were analyzed by using SPSS 10.0 software with various techniques such as paired t-test, T-test, Cronbach's ${\alpha}$ reliability and factor analysis that use principal component analysis and Varimax orthogonal rotation were used. The results are summarized as follows: 1. By categorizing the level of on-line store characteristics satisfaction depending on its type, clarifies the differences between its satisfaction. The satisfaction rank of general merchandise store was as followed: searching and approaching system, buying process service, screen-displayed design, product, store credit. On the other hand, the satisfaction rank of general store was as followed: screen-displayed design, store credit, buying process service. 2. By analyzing the difference of satisfaction depending on the store type, it was found that general merchandise store was more satisfied with screen-displayed design, approaching and searching, whole payment process, the safety of payment and shipping service, security service when compared to specialty store. It was also found that specialty store was more satisfied with the variety of product, update of rare items, quality and price of product. 3. By analyzing the difference between the type of on-line clothing store satisfaction depending on age, in the case of general merchandise store, the result showed that people in their thirties were more satisfied with buying process service, store credit, customer management system when compared to twenties. In the case of specialty store, the result showed that people in their twenties were more satisfied with customer management service when compared to thirties, and when it came to buying process service, it was vice versa.

• Structural Engineering and Mechanics
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• v.32 no.2
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• pp.251-267
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• 2009

Reinforced concrete (RC) structures consist of two different materials: concrete and steel bar. The stress transfer behaviour between the two materials through bond plays an important role in the load-carrying capacity of RC structures, especially when they subject to lateral load such as blast and seismic load. Therefore, bond and slip between concrete and reinforcement bar will affect the response of RC structures under such loads. However, in most numerical analyses of blast-induced structural responses, the perfect bond between concrete and steel bar is often assumed. The main reason is that it is very difficult to model bond slip in the commercial finite element software, especially in hydrodynamic codes. In the present study, a one-dimensional slide line contact model in LS-DYNA for modeling sliding of rebar along a string of concrete nodes is creatively used to model the bond slip between concrete and steel bars in RC structures. In order to model the bond slip accurately, a new approach to define the parameters of the one-dimensional slide line model from common pullout test data is proposed. Reliability and accuracy of the proposed approach and the one-dimensional slide line in modelling the bond slip between concrete and steel bar are demonstrated through comparison of numerical results and experimental data. A case study is then carried out to investigate the bond slip effect on numerical analysis of blast-induced responses of a RC column. Parametric studies are also conducted to investigate the effect of bond shear modulus, maximum elastic slip strain, and damage curve exponential coefficient on blast-induced response of RC columns. Finally, recommendations are given for modelling the bond slip in numerical analysis of blast-induced responses of RC columns.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.449-455
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• 2015

Owing to the trend of an increase in capacity and high-efficiency requirement, the life and reliability of power transformer depend significantly on the amount of heat generation per unit volume and the degradation of insulation oil. These problems can be solved by enhancing the cooling performance of the radiator. The purpose of this study was to find a suitable position of fans for a better cooling effect given by the forced-convection of air in an ONAF (Oil Natural Air Forced) type transformer. In the simulation, commercial software was used for flow analysis, and the cooling passage of the oil was simplified to shorten the time taken for computation. With the diameter of the fan fixed at a constant value, the analysis was performed only by changing the position of the fans. As a result, a vertical position change of the fans does not affect the cooling performance significantly. However, the temperature drop given by the fans positioned on the front region of the transformer is larger than that on the rear region.

• Journal of East-West Nursing Research
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• v.6 no.1
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• pp.7-22
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• 2001

This study is a discriptive research to identify stress and powerlessness based on Korean hemodialysis patients' constitution. Research subject was 112 hemodialysis patients who are treatment processing in P university hospital and K hemodialysis hospital in S City, and the data were collected for 60 days from December 20, 1999 to January 30, 2000. The research tools used for the measurement of constitution was "QSCC II", the measurement of the stress was Jeon chi ja's "Scale of Hemodialysis patient's Stress"(1985), and the measurement of powerlessness was Kim joe ja's "Scale of Powerlessness"(1992). The reliability of the scale for stress is Cronbach's Alpha 0.8819 and that of powerlessness is Cronbach's Alpha 0.6993. Data analysis was performed using SPSSWin 9.0 software. We tested them with real number, percentage, average score, standard deviation, t-test, F-test(ANOVA), Pearson's Correlation Coefficient, and Multiple stepwise regression. The results of this study were as follows : 1. Hemodialysis patients' constitution were : Soyangin 38.4%, Taemin 34.8%, and Soeumin 26.8%. 2. The average score of the stress by hemodialysis patients were the mean $89.72{\pm}20.26$ points. The average score of powerlessness was the mean $34.19{\pm}6.46$ points, by hemodialysis patients. 3. The result of the Pearson Correlation showed no correlation between the score of stress and the score of powerlessness. 4. In their relationship between general characteristics and the score of stress : in marriage state, job(P=0.016, P=0.007) and In their relationship between general characteristics and the score of powerlessness : in age, marriage state, educational level, job(P=0.000, P=0.012, P=0.002, P=0.050) have statistically meaningful differences. 5. The factor affecting the powerlessness of hemodialysis patients was physical area of stress and its explanatory power was 18.5%.

• International journal of advanced smart convergence
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• v.4 no.2
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• pp.109-119
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• 2015

The interaction between wireless sensors such as Internet of Things (IoT) and Cloud is a new paradigm of communication virtualization to overcome resource and efficiency restriction. Cloud computing provides unlimited platform, resources, services and also covers almost every area of computing. On the other hand, Wireless Sensor Networks (WSN) has gained attention for their potential supports and attractive solutions such as IoT, environment monitoring, healthcare, military, critical infrastructure monitoring, home and industrial automation, transportation, business, etc. Besides, our virtual groups and social networks are in main role of information sharing. However, this sensor network lacks resource, storage capacity and computational power along with extensibility, fault-tolerance, reliability and openness. These data are not available to community groups or cloud environment for general purpose research or utilization yet. If we reduce the gap between real and virtual world by adding this WSN driven data to cloud environment and virtual communities, then it can gain a remarkable attention from all over, along with giving us the benefit in various sectors. We have proposed a Pub/Sub-based sensor virtualization framework Cloud environment. This integration provides resource, service, and storage with sensor driven data to the community. We have virtualized physical sensors as virtual sensors on cloud computing, while this middleware and virtual sensors are provisioned automatically to end users whenever they required. Our architecture provides service to end users without being concerned about its implementation details. Furthermore, we have proposed an efficient content-based event matching algorithm to analyze subscriptions and to publish proper contents in a cost-effective manner. We have evaluated our algorithm which shows better performance while comparing to that of previously proposed algorithms.

• The Journal of Korean Association of Computer Education
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• v.9 no.2
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• pp.27-36
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• 2006

This study intends to present essential models for collaborative learning in e-learning environment as well as to analyze learning behavior elements appearing in collaborative learning activities. In order to achieve goal of the study, the researchers analyzed existing cooperative learning models for face-to-face classroom, collaborative activity models based on instructional theory, and the structures and activities elements of learning community and collaborative activity models focusing on e-learning environment. As a result of the study, the researchers produced a generalizable collaborative learning model for e-learning which include general collaborative learning model, and further analyzed specific learning behaviors performed by learners while they proceed in this model based learning processes. The adequacy of this model and reliability of learning behavior elements were tested through experts' review meetings. The research result, suggesting generalizable collaborative learning model as well as learning behaviors elements which might occur within e-learning based collaborative learning, might work as a foundational model for software infrastructure and e-learning solution business. Moreover, its value might be maximized if its being used for enhancing learning content interoperability and reuse as well as for establishing international standardization for collaborative technology.