• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.917-920
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• 1988

The effects of the errors due to incorrect a priori informations on the noise model as well as the system model in the continuous state model based optimal FIR filter is considered. When the optimal filter is perturbed, the error covariance is derived. From this equation, the performance of the state model based optimal FIR filter is analyzed for the given modeling error. Also the state model based optimal FIR filter is compared to the standard Kalman filter by an example.

• Journal of Information Technology Services
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• v.12 no.1
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• pp.173-187
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• 2013

The advent of Web2.0 has believed to be the solution against many barriers in information sharing, especially wiki. Information sharing and collaboration are realized voluntarily and unselfishly with wiki. The purpose of this paper is to analyze the benefits and challenges of using wiki as a project management method in an IT/IS project. Wiki-based project management could provide project managers and members with expert knowledge collaboration for better project results. In the research model, we used TMS(Transactive Memory System) theory to define the relation of collaboration and performance of project members. Based on a survey among project members, the interactions between wiki characteristics and performance are examined in an IS project environment. Using Smart PLS 2.0, the data was analyzed to define the interactions by the structural equation modeling. From the empirical data, the mediated effect of expert knowledge collaboration is supported. We also derive the implications of wiki-based method. It is expected to bring new possibilities of Project management performance.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.3-9
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• 1999

This paper concerns performance of a parallel digital signal processing system. The performance of the system is analyzed in terms of CPU cycles required for 1024-point FFT computation. The number of cycles is estimated in three different approaches; FFT algorithm-based, assembly level source code-based, and probability-based. The results of analysis indicate that on a bus-based system the best performance for FFT is achieved with a single board. Because in some applications like FFT, where frequent data exchanges among processors occur, the number of communication cycles increases as the number of boards. It is observed that inter-board communication degrades overall system performance for the FFT computation. Also shown is that linear increase in performance can be obtained if multiple buses are employed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3321-3341
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• 2014

This paper investigates the outage performance and optimization for the four-phase two-way transmission network with an energy harvesting (EH) relay. To enable the simultaneous information processing and energy harvesting at the relay, we firstly propose a power splitting-based two-way relaying protocol (PSTWR). Then, we discuss its outage performance theoretically and derive an explicit expression for the system outage probability. In order to find the optimal system configuration parameters such as the optimal power splitting ratio and the optimal transmit power redistribution factor, we formulate an outage-minimized optimization problem. As the problem is difficult to solve, we design a genetic algorithm (GA) based algorithm for it. Besides, we also investigate the effects of the power splitting ratio, the power redistribution factor at the relay, and the source to relay distance on the system outage performance. Finally, extensive simulation results are provided to demonstrate the accuracy of the analytical results and the effectiveness of the GA-based algorithm. Moreover, it is also shown that, the relay position greatly affects the system performance, where relatively worse outage performance is achieved when the EH relay is placed in the middle of the two sources.

• English Language & Literature Teaching
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• v.18 no.2
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• pp.45-66
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• 2012

The purpose of this study was to investigate the impact of two different SNS-based tasks on university students' English writing performance. To address our primary research question, Me2day, microblogging and Social Networking Service, was employed. 43 university students were divided into two experimental groups depending on the task types: a comparison task group and a sharing personal experiences task group. The main findings of the study were as follows: first, two different types of SNS-based tasks, 'spot the differences' and 'writing diaries', had a positive effect on learners' writing performance. The reason for this was that the succinct messages limited to 150 characters made it easier for the students to try writing in English without burden; and they may benefit from their peers by seeing their posts and interacting with each other. Yet there were no significant differences between the two groups when it came to the degree of improvement. Second, two different types of SNS-based tasks differently fostered certain aspects of the writing performance; 'contents knowledge' was supported by the 'writing diaries' task and range was supported by the 'spot the differences' task. Third, learners in the two experimental groups mostly had positive impressions regarding usage of Me2day as a new learning tool.

• Journal of Korean Society for Quality Management
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• v.48 no.3
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• pp.421-431
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• 2020

Purpose: The purpose of this study is to compare and analyze the tokenizer in natural language processing for customer satisfaction in sentiment analysis. Methods: In this study, a supervised learning-based tokenizer Mecab-Ko and an unsupervised learning-based tokenizer SentencePiece were used for comparison. Three algorithms: Naïve Bayes, k-Nearest Neighbor, and Decision Tree were selected to compare the performance of each tokenizer. For performance comparison, three metrics: accuracy, precision, and recall were used in the study. Results: The results of this study are as follows; Through performance evaluation and verification, it was confirmed that SentencePiece shows better classification performance than Mecab-Ko. In order to confirm the robustness of the derived results, independent t-tests were conducted on the evaluation results for the two types of the tokenizer. As a result of the study, it was confirmed that the classification performance of the SentencePiece tokenizer was high in the k-Nearest Neighbor and Decision Tree algorithms. In addition, the Decision Tree showed slightly higher accuracy among the three classification algorithms. Conclusion: The SentencePiece tokenizer can be used to classify and interpret customer sentiment based on online reviews in Korean more accurately. In addition, it seems that it is possible to give a specific meaning to a short word or a jargon, which is often used by users when evaluating products but is not defined in advance.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.1
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• pp.1-10
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• 2017

Recently, with the ever-increasing complexity of industrial robot systems, it has been greatly attention to adopt a multi-core based motion controller with high cost-performance ratio. In this paper, we propose a software architecture that aims to utilize the computing power of multi-core processors. The key concept of our architecture is to use shared memory for the interplay between threads running on separate processor cores. And then, we have integrated our proposed architecture with an industrial standard compliant IDE for automatic code generation of motion runtime. For the performance evaluation, we constructed a test-bed consisting of a motion controller with Preempt-RT Linux based dual-core industrial PC and a 3-axis industrial robot platform. The experimental results show that the actuation time difference between axes is 10 ns in average and bounded up to 689 ns under $1000{\mu}s$ control period, which can come up with real-time performance for industrial robot.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.22 no.3
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• pp.308-317
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• 2015

Purpose: The aim of this study was to examine the effects of case-based learning (CBL) on clinical decision making and nursing performance. Methods: This research was conducted between September, 2011 and January, 2012 as a nonequivalent comparison group design. The participants were 55 third year nursing students who were enrolled in a college of nursing in a university in Korea. The intervention was the CBL procedures which involved role-play practice videoed by camera and watched on the computer by the students. Questionnaires were used before and after the intervention to measure clinical decision-making. Nursing performance tests were done after the intervention. Results: Statistically significant group differences were observed in clinical decision-making. Nursing performance was significantly higher in the CBL group than in the control group. Conclusion: CBL focused on the solving problem process and clinical cases which are based on clinical setting allowing students to develop efficiency in clinical practice and adaptation to the clinical situation.

• Korean Journal of Clinical Pharmacy
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• v.23 no.3
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• pp.278-283
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• 2013

Background: Problem-based learning (PBL) has introduced as an important part of pharmacy education in Korea as it is effective method to help students gain and apply knowledge with development of problem-solving, critical-thinking, and decision-making skills. In order to provide the effective PBL, a number of trained facilitators and suitable PBL rooms are required. However, these become a barrier in Korea as most pharmacy schools have one or two faculty members who majored in clinical pharmacy. Objective: This study was performed to implement and evaluate a modified PBL in gastrointestinal (GI) pharmacotherapy class facilitated by one instructor. Methods: A general information of traditional PBL for 6 hours through 3 days is introduced before initiating GI pharmacotherapy class. After 3 hour-GI pharmacotherapy classes for 6 weeks, modified PBL was implemented with one instructor to facilitate PBL for four small groups with 19 pharmacy students simultaneously. Modified PBL was incorporated with weekly mini-case discussion and presentation. Results: Students completed 15-question survey to evaluate modified PBL course, student performance, group performance, and facilitator performance. Eighty-four percent of students answered modified PBL was helpful to understand what they have learned. Mean score in group performance was higher than that of individual performance during modified PBL course. Overall, students reported modified PBL was useful in knowledge building. Conclusion: Modified PBL model without individual group facilitators in one classroom helped students to achieve self-directed, independent learning skills in an interactive and engaging environment.

• The Korean Journal of Emergency Medical Services
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• v.18 no.3
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• pp.91-104
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• 2014

Purpose: This study aimed to confirm the effects of a simulation-based program on knowledge and clinical performance in the post-operative management of emergency patients. Methods: This was a pre- and post-research design with a nonequivalent control group and randomly sampled 29 experimental and control groups, respectively from nursing department juniors for 4 weeks from September of 2014. The experimental group received lectures, team study, team simulation, and debriefing in post-operative management of simulation-based emergency patients and control group conducted in the traditional lecture-type setting. Educational learning effects were measured by using the knowledge and clinical performance measurement tools of 15 and 20 items, respectively. Data were analyzed by using the SPSS program, including frequency, ratio, and results from the Chi-square test, Fisher's exact test, Kolmogorov-Smirnov test, t-test. Results: Our research results indicate that, the experimental group showed significantly higher knowledge and clinical performance score compared with the control group. Conclusion: We confirmed that education on post-operative management of simulation-based emergency patients was an effective educational method to improve the knowledge and clinical performance of nursing students.