• PNF and Movement
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• v.12 no.2
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• pp.97-106
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• 2014

Purpose: The purpose of this study was to investigate changes in EEG through attention. Concentration training and performing tasks are important factors in the improvement of motor learning ability. Methods: In the experiment, 22 healthy people were divided into two groups: the trail making test (TMT) group and the computerized neurocognitive function test (CNT) group. A one-way Neuro Harmony M test to see whether there was a significant difference among the groups. Results: The TMT group showed a significant increase in ${\alpha}$ wave, ${\alpha}$ wave sequence, and ${\beta}$ wave sequence; however, there were no significant differences in SMR wave, SMR wave sequence, and ${\beta}$ wave. The CNT group showed increases in ${\alpha}$ wave, ${\alpha}$ wave sequence, SMR wave, SMR wave sequence, and ${\beta}$ wave sequence; however, there was no significant difference in ${\beta}$ wave. In EEGs before and after two performance tasks were changed, there were significant differences in ${\beta}$ wave, SMR wave, SMR wave sequence; however, there were no significant differences in ${\alpha}$ wave sequence, ${\beta}$ wave, and ${\beta}$ wave sequence. Conclusion: Attention training and concentration training offer feedback and repetition for constant stimulus and response. Moreover, attention training and concentration training can contribute to new studies and motivation by developing fast sensory and motor skills through acceptable visual and auditory stimulation.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.193-200
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• 2007

This study investigated the effects of situational context feedback in CAI upon students' conceptual understanding, science learning motivation, and the perception of CAI. Seventh graders (N = 114) from a coed middle school in Incheon were assigned to the situational context feedback CAI (SCF-CAI), the feedback CAI (F-CAI) and the CAI groups, and were taught about ‘three states of matter' and ‘motion of molecules' for 8 class hours. Prior science achievement test score used as a blocking variable. Two-way ANCOVA results revealed that the conceptual understanding test scores of the SCF-CAI group were significantly higher than those of the other groups. For the higher achievers, the scores of the F-CAI group in science learning motivation test were significantly higher than those of the CAI group. However, there was no significant difference among the lower achievers of three groups. The higher achievers in the SCFCAI and the F-CAI groups perceived the CAI more positively than those of the CAI group. The lower achievers in the FCAI group perceived the CAI more negatively than those of the other groups. Educational implications are discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.617-626
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• 2008

Opportunistic Beamforming (OBF) offers a way to provide the multiuser diversity even in slow fading channel by using randomly generated beam weights, leading to the substantially reduced feedback in the form of the instantaneous SNR from users. In spite of the advantage of the reduced feedback, the imperfect channel estimation might influence the quality of the estimated SNR and channel scheduler so bad that the selected AMC level would be higher than the achievable rate of the actual channel, resulting the corruption of transmitted packet. In this paper, we propose a conservative link adaptation, where the estimated SNR is scaled down by a conservative factor which minimizes the variance of the maximum difference between the actual channel SNR and the resultant SNR. To support the proposed scheme, we analyze the statistics of the difference of the channel SNR and the estimated SNR. Simulation results show that the introduction of conservative factor achieves more than two-fold performance improvement in the presence of channel estimation error and the fairness of PF scheduler is maintained when the least squared channel estimator is applied.

• The Journal of Information Systems
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• v.17 no.3
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• pp.205-233
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• 2008

This study suggests the dynamic value chain model, that will be able to not only show changing processes to organization's significant capital by integrating an individual, implicit, and explicit knowledge which affect organizational decision making, but also distinguish the key driver for raising organizational competitive power because it makes possible to analyze sensitivity of performance along with decision making alternatives and policy changes from dynamic view by connecting knowledge management capability, knowledge management activity, and relations with organizational performance with specific strategic map. Recently, a lot of organizations show interest in measuring and evaluating their performance synthetically. In organizations taking knowledge management, they introduce effective value chain model like a dynamic balanced scorecard (DBSC), and therefore they can reflect their knowledge management condition as well as show their changes by checking performance of established vision and strategy periodically. Furthermore, they can ask for their inner members' understanding and participation by communicating with and inspiring their members with awareness that members are one of their group, present a base of benchmarking, and offer significant information for later decision making. The BSC has been a successful framework for measuring an organization's performance in various perspectives through translating an organization's vision and strategy into an interrelated set of key performance indicators and specific actions. The BSC, while having significant strengths over traditional performance measurement methods, however, has its own limitations, due to its static nature, such as overlooking two-way causation between performance indicators and neglecting the impact of delayed feedback flowing from the adoption of new strategies or policy changes. To overcome these limitations, this study employs SD, a methodology for understanding complex systems where dynamic feedback among the interrelated system components significantly impact on the system outcomes. The SD simulation model in the form of DBSC would serve as a useful strategic teaming tool for facilitating an organization's communication process through various scenario analyses as well as predicting the dynamic behavior pattern of their key performance measures over a future time frame. For the demonstration purpose, this study applied the DBSC model to Prototype of Korea manufacturing and service firm.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.36-47
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• 1999

Three-way catalyst converter, cleaning up the exhaust gas contamination of SI engine, has the best efficiency when A/F ratio is near the stoichiometry . The feedback control using oxygen sensors in the exhaust manifold has limits caused by the system delays. So the accurate measurement of air flow rate to an engine is essential to control the fuel injection rate especially on transient condition like the rapid throttle opening and closing. To measure the rapid change of flow rates. the air flow meter for the engine requires quick response, flow reversal detection, and linearity . Tjhe proposed integration type air flow meter (IFM), composed of an ultrasonic flow meter with an integration circuit, has significantly improved the measurement accuracy of air mass inducted through the throttle body. The proposed control method estimated the air mass at the cylinder port using the measured air mass at the throttle . For the fuel dynamic model, the two constant fuel model is introduced . The control parameters from air and fuel dynamics are tuned to minimize the excursion of the air fuel ratio. As a result A/F ratio excursion can be reduced within 5% when throttle rapidly opens and closes at the various engine conditions.

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.151-164
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• 2001

Currently, there are little evaluated model for each industry and systematic analysis for each item about current business web sites. And the approach way to improve it all depends on individual. This research is about two different points of view on I-Evaluation development as an approach method to provide analysis, evaluation, and guideline on business web sites. The one is about developing a working step and a site evaluation model that are necessary to improve the quality of site. The other is about a framework development to apply a feedback on site most rapidly and site optimization. The former is from the methodological point of view for I-Evaluation, and the latter is from the point of view for I-Evaluation Framework. In terms of methodology, developing site evaluation model and defining a working step belong to it. Site evaluation model means customizing each customers web site, using each evaluated scoring model which can be a standard for each industry to analyze a similar business web site. Defining a working step means defining input and output parameters for composed elements, working processes, and results analysis on an evaluated model. And also it includes building a working environments to automatic steps mentioned the above by clarifying them.

• Culinary science and hospitality research
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• v.10 no.2
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• pp.59-71
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• 2004

This study .is about marketing of menu-delivery-web site through internet which is getting bigger in working-together-couples. The purpose of this study is suggesting the way which can make internet marketing to activate by means of analysing of a certain enterprise's homepage with marketing mix method. We draw the findings which is seperated by goods, price, promotion, distribution, other service according to marketing constituents. As a result of research, it was found that each company has given much more weight on some part in internet marketing's field of activity. In general, they put an empasis on activity of goods and promotion. On the other hands they didn't consider prices and delivery to be important compared with other parts. In a field of price, menu-site just announced price but in further advance, it had better offer and compare two price level when customer used menu-delivery-web site or not. And that site needed to promote and to be advertised what customer who just think using web site was expensive have benefit in the price. One of the most important things about internet-marketing was that fast and exact feedback and community made each enterprise to be able to help to communicate with customer. For these strategy to execute effectively, first company's name should be known well and goods and service the company had should be well advertised. But first of all, differentiated strategy should precede through consistency of taste and quality, consistant information update as a internet-company and sincere homepage management.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.3
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• pp.73-82
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• 1992

An industrial robot, installed real manufacturing processes an element of the system autmation, can be considered as an uncertain system due to dynamic uncertainties in inertial parameters and varying payloads. Most difficuties in controlling a robot manipulator are caused by the fact that the dynamic equations describing the motions of the manipulator are inherently nonlinear and heavily coupled effects between joints and associated links. Existing robot conrol systems have constant predefined gains and do not cover the complex dynamic interactions between manipulator joints. As a result, the manipulator is severly limited in range of application, speed of operation and variation of payload. The proposed controller is operated by adjusting its gains based on the response of the manipulator in such a way that the manipulator closely matches the reference model trajectories defined by the desinger. The proposed manipulator studied has two loops, an inner loop of model reference adaptive controller and an outer loop of state feedback controller with integral action to guarantee the stability of the adaptive scheme. This adaptation algorithm is based on the hyperstailiy approach with an improved Lyapunov function. The coupling among joints and the nonlinearity in the dynamic equation are explicitly considered. The designed manipulator controller shows good tracking performance in practical working environment, various load variations and parameter uncertainties.

• Korean Medical Education Review
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• v.18 no.3
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• pp.156-166
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• 2016

Medical school students learn a lot about medical knowledge and clinical experience in the classroom. Teaching is a main focus in medical schools; therefore, it is necessary to identify the characteristics of good teaching. The aim of this study is to analyze the characteristics of high-quality education in medical schools. In this study, in-depth interviews were conducted over two weeks on twelve fourth-year medical students. Participants were asked to define high-quality education, list the general ways in which high-quality classes are delivered, mention cases where they have experienced high-quality teaching, and describe the attitude required of students to make high-quality education possible. The results showed that students want to be taught in an interactive way on the core content needed in an actual clinical setting for the goal of cultivating primary care physicians. They want their education to include not only medical knowledge, but also liberal art subjects such as politics, economics, sociology, culture and ethics education to help instill a sound value system. In particular, students stressed the importance of instructors delivering appropriate post-evaluation feedback, and they also emphasized that learner mindset and attitude is important in supporting high-quality teaching in class. This paper also summarizes the elements of high-quality teaching in terms of educational goals, content, and method, and examines cases of instructors who have delivered high-quality classes.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1174-1176
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• 2011

Unfortunately, the number of blind people increases every 5 seconds in our world. An extensive research was made on improving the conventional walking cane and developing a microcontroller based walking stick for the blind with sensors and a feedback in form of vibration. Two different kinds of sensors are used to detect obstacles, ultrasonic and infrared distance sensors. The signal from an ultrasonic sensor is fed to a microcontroller. With the help of the supporting software, the Pulse Width Modulation (PWM) principle is extensively used to form three zones and run the corresponding vibration motor at different spends according to how far the detected object is located. The other infrared distance sensors are connected to amplifiers and after that to their corresponding vibration motors through motor drivers. The vibration motors are to be located around the user's arm to notify the blind of the obstacles in the intended walking way. It can be very reliable and sufficient device guiding the blind other than the conventional walking cane which has many drawbacks which will be explained and discussed.