• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.7
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• pp.335-343
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• 2006

We have designed the system that measure one channel ECG by two electrode and extract real-time EDR with more related resipiration and comportable to subject by using conductive textile. On the assumption that relation between RL electrode and potential measurement electrode is coupled with RC connected model, we designed RL drive output to feedback two electrode for reduction of common mode signal. The conductive textile which was used for two ECG electrode was offered more comfort during night sleep in bed than any other method using attachments. In the method of single-lead EDR, R wave point or QRS interval area could be used for EDR estimation in traditional method, it is, so to speak, the amplitude modulation(AM) method for EDR. Alternatively, R-R interval could be used for frequency modulation(FM) method based on Respiratory Sinus Arrhythmia(RSA). For evaluation of performance on AM EDR and FM EDR from 14 subject, ECG lead III was measured. Each EDR was compared with both temperature around nose(direct measurement of respiration) and respiration signal from thoracic belt(indirect measurement of respiration) on mean squared error(MSE), cross correlation(Xcorr), and Coherence. The upsampling interpolation technique of multirate signal processing is applied to interpolating data instead of cubic spline interpolation. As a result, we showed the real-time EDR extraction processing to be implemented at micro-controller.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.7-12
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• 2011

This paper proposes a differential Colpitts-VCO circuit suitable for low phase noise oscillation at the sub-1V supply voltage. Oscillation with low phase noise at the sub-1V supply voltage is facilitated by employing inductors as the current sources of the proposed circuit. One of the two feedback capacitors of the single-ended Colpitts oscillator in the proposed circuit is replaced with the MOS varactor in order to further reduce the resonator loss. Post-layout simulation results using a $0.18{\mu}m$ RF CMOS technology show that the phase noises at the 1MHz offset frequency of the proposed circuit oscillating at the sub-1V supply voltages of 0.6 to 0.9 V are at least 7 dBc/Hz lower than those of the well-known cross-coupled differential VCO.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.738-749
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• 2011

In this paper, we study QoS(Quality of Service) control protocols and the effect using MAC/PHY parameters of client device in mobile network. We proposes the way of controling the bit-rate by estimating the channel condition of the client with measured MAC/PHY parameters which is sent from the client. With the proposed method, more accurate available bit-rate can be estimated compared to conventional protocol, RTCP(Real-time Transport Control Protocol). The accurate bit-rate estimation can decrease wasted bit-rate and transport delay. In the result of the advantages, the transported video quality can be enhanced. In this paper, we show the effects of enhancement using client's the field data measured in WiMAX.

• Journal of Korean society of Dental Hygiene
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• v.15 no.1
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• pp.137-146
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• 2015

Objectives: This study was obtained to identify current education status of the community dental hygiene practice. Methods: It was designed cross section and self-reported on-line questionnaire(Survey monkey). It was performed probability sampling by targeting 82 dental hygiene schools(each one faculty member) in charge of community dental hygiene curriculum and 254 community health centers's community dental hygienists whom was working at oral health section. The response rate was 60% and 53%, respectively. The questionnaire consisted of time, duration, practice group, evaluation method, and practice contents including 63 learning objectives of dental hygiene. Results: Nearly half of these schools conduct such community field work practice in the spring semester of the junior year. This practice was mainly progressed based on average 4 students as one team per each one school for 7-8 hours a day during the period of more than 5 weeks(p<0.05). However, in case of both school and community health center, almost half of feedback after practice was not achieved and there was a difference in needs for practice education between schools and community health center. Conclusions: We should be considered that a sufficient consultation for the practice environment and its contents between schools and community health centers. It was considered that development of a standardized practice manual reflecting such requirement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.177-182
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• 2007

This paper presents the InGaP/GaAs HBT differential LC VCO with low phase noise performance for adaptive feedback interference cancellation system(AF-lCS). The VCO is verified with enhanced tank structure including filtering technique. The output tuning range for proposed VCO using asymmetric inductor and symmetric capacitors withlow pass filtering technique is 207 MHz. The output powers are -6.68 including balun and cable loss. The phase noise of this VCO at 10 kHz, 100 kHz and 1 MHz are -102.02 dBc/Hz, -112.04 dBc/Hz and -130.40 dBc/Hz. The VCO is designed within total size of $0.9{\times}0.9mm^2$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.283-289
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• 2010

Owing to the increasing worldwide interest in green technology and renewable energy sources, flywheel energy storage systems (FESSs) are gaining importance as a viable alternative to traditional battery systems. Since the energy storage capacity of an FESS is proportional to the principal mass-moment of inertia and the square of the running speed, a design that maximizes the principal inertia while operatingrunning at the highest possible speed is important. However, the requirements for the stability of the system may impose a constraint on the optimal design. In this paper, an optimal design of an FESS that not only maximizes the energy capacity but also satisfies the requirements for system stability and reduces the sensitivity to external disturbances is proposed. Cross feedback control in combination with a conventional proportional-derivative (PD) controller is essential to reduce the effect of gyroscopic coupling and to increase the stored energy and the specific energy density.

• Journal of Internet Computing and Services
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• v.22 no.4
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• pp.65-82
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• 2021

A well-designed website is mandatory for good marketing and proper tourism business. This research considers Nepal as a domain of study and specifically explores welcomenepal.com, the official tourism portal as a reference for the study. The work is based on the study of the existing literature, user-survey, and technical testing of the website using open-source testing tools to identify user perspective, design issues, website architecture and design quality of the tourism website. A population size of 400 respondents, which consist of both domestic and international tourist, are considered for the survey. Data is received from 360 respondents, which is analyzed using statistical tests like Cronbach's alpha, Pearson's correlation, cross-tabulations, bars charts and graphs to draw inferences and consclusion. The software-based test results serve as another important parameter for the evaluation of the current official website. This study brings out core needs of the tourist in terms of expectations from a tourism website and access technical quality of the current portal to provide necessary feedback and suggestions. The government officials, business houses, and web designers can utilize this work as a knowledge base to build tourism websites, which are user-centric. Further, the work is specifically important for Nepal government and tourism officials to identify shortcomings in their current website and make improvements for better design and user adaptability in future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.3
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• pp.193-201
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• 2022

SOQPSK-TG is a modulated signal for aircraft telemetry with excellent frequency efficiency and power efficiency. In this paper, the phase waveform of the partial response SOQPSK-TG modulation is linearly approximated and modeled as a full response double duobinary SOQPSK (SOQPSK-DD) signal. And using the XTCQM method and the Laurent decomposition method, the SOQPSK-DD signal was approximated as OQPSK having linear pulse waveforms, and the results of the two methods were proved to be the same. In addition, it was confirmed that the Laurent decomposition waveform of the SOQPSK-DD signal approximates the Laurent decomposition waveform of the original SOQPSK-TG signal. And it was shown that the decision feedback IQ-detector, which applied the Laurent decomposition waveform of SOQPSK-DD to the detection filter, exhibits almost the same performance even with a simpler waveform than before.

• Journal of Fashion Business
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• v.27 no.4
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• pp.125-140
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• 2023

This study aimed to develop a smart wearable device for assessing the risk angle associated with turtle neck syndrome in patients with Video Display Terminal (VDT) syndrome. Turtle neck syndrome, characterized by forward head posture resulting from upper cross syndrome, leads to thoracic kyphosis. In this research, a stretch sensor was used to monitor the progression of turtle neck syndrome, and the sensor data was analyzed using a Universal Testing Machine (UTM) and the Gauge Factor (GF) calculation method. The scapula and cervical spine angles were measured at five stages, with 15-degree increments from 0° to 60°. During the experimental process, the stretch sensor was attached to the thoracic spine in three different lengths: 30mm, 50mm, and 100mm. Among these, the attachment method yielding the most reliable data was determined by measuring with three techniques (General Trim Adhesive, PU film, and Heat Transfer Machine), and clothing using the heat transfer machine was selected. The experimental results confirmed that the most significant change in thoracic kyphosis occurred at approximately 30° of forward head posture. Prolonged deformity can lead to various issues, highlighting the need for textile sensor solutions. The developed wearable device aims to provide users with real-time feedback on their turtle neck posture and incorporate features that can help prevent or improve the condition.

• Cross-Cultural Studies
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• v.25
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• pp.695-721
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• 2011

The purpose of this study is to provide the case study of expression education using story-telling about their cultures from which they came to the women who get interracial married and study korean cultures with the pride of their homeland. This research is also for the diverse members of korean society to deeply understand interracial married women, get higher understanding cultural diversities. And it is expected that these women could learn and study more korean cultures, too. In this study, process-based instruction method is used in the first step and second step such as brainstorming, questioning, discussing, investigating, teacher's asking in order to create some ideas about their home countries. Suggesting an example answer by teacher and free-writing are also involved. As the core of the process-based writing activity, the second step is focused on revising and correcting. Through reviewing their own writing task, feedback from teacher, interviewing from the difficulty of writing after this activity to cultural and linguistic backgrounds, they could appreciate their errors or mistakes in writing are natural and this affects their learning abilities positively. In third step which is focused on speaking activities, teacher provides feedback to learners after checking their common errors or habits in speaking. Meanwhile, by evaluating the role of the appraiser, It is helpful for the learners to have self-esteem of their own. When interviewing after fourth step's activities, the teacher compliments each learner's improvement while pointing out some errors. Afterward, We can see they show more positiveness to learn and understand korean cultures and set their identities. And they indicate interests and concerns each other's cultures by story-telling. It means they identify the popularity and interaction which the story-telling contains. Also, they confirm the participation in story-telling by expressing their willingness to revise their stories. After the activities in fifth step, there have been relatively positive changes in establishing identity and cultivating a sense of pride of learner's homeland cultures. Furthermore, we could find the strong will to be a story-teller about their homeland cultures. On this research, the effectiveness of expression education case study using story-telling about local cultures of interracial married women's homeland has been examined centrally focused on popularity, interaction, and participation. Afterward, interracial married women could not only cultivate the understanding about korean cultures but also establish their identity, improve their korean language skills through this education case study. Finally, the studies of the education programs to train interracial married women as story-tellers for their homeland local cultures are expected.