• The Journal of the Korea Contents Association
• /
• v.15 no.12
• /
• pp.185-192
• /
• 2015

This study analyzed the spatial interrelation between living wages and economic variables and how they operate based on systems thinking theory to understand what value living wages have as policy instruments and why they are necessary. Results from this study can be summed as follows. First, the relationship between living wages and economic variables shows close interaction at a considerable level. In particular, mutual feedback which connects to laborers' standards of living, consumption, business, and economy was operating closely. Second, largely three positive (+) feedback loops were operating in the feedback structure of living wages and economic variables. This can be interpreted to mean that positive economic variables which are associated with living wages have the possibility of growth. Also, it can mean that the minimum wage system did not fully fulfill its role. Through these study results, it can be learned that living wages have sufficient value as a policy means and that it is advisable to allow living wages to exceed simple application levels in the public sector to expand into the private sector, to bring positive change to the economic system.

• Journal of Sensor Science and Technology
• /
• v.12 no.3
• /
• pp.121-127
• /
• 2003

In this study, we carried out a study for implementation of the pre-amplifier and the digital signal processing part for the potable EEG biofeedback system. As we consider characteristics of the EEG signal, we designed the pre-amplifier to obtain the EEG signal to be reduced noise signal. Because the EEG signal include EOG, EMG, ECG signals etc, it is difficult to analyze of the EEG signal. Therefore, we developed DSP board and operation program which was embed the LMS adaptive filter algorithm and operate with the pre-amplifier in the real time. The simulation signal and pure EEG signal is used in the experiment. As the result, we confirmed good efficiency of developed system and possibility of application to the portable EEG biofeedback system.

• Science of Emotion and Sensibility
• /
• v.21 no.3
• /
• pp.165-176
• /
• 2018

The objective of this study was to develop clothing-type wearable motion sensing and feedback systems to enhance children's sports by promoting visual and audio feedback. In this study, several applications, such as fabric sensors, sportswear integrated with various types of fabric sensors, and fabric-based motion sensing module design, as well as a visual and audio feedback system for gaining a better understanding of a child's interest in a type of exercise, were developed. An SWCNT-based stretchable fabric sensor was developed for motion sensing, and sportswear was designed using the fabric sensor that was integrated into the limbs of the garment. The sensing module was developed, and sensory performance was evaluated through a joint motion experiment for children. In addition, using the feedback system that was developed in the form of an accessory, the responses of light and sound were also examined based on the movement of the child who was wearing the sportswear prototypes. This study focused on the development and assessment of prototype designs for children's sportswear and accessory products that can help to ascertain a child's interest in a particular exercise.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.5A
• /
• pp.511-520
• /
• 2011

In this paper, we introduce a multiuser (MU) scheduling method for multiuser amplify-and-forward relay systems, which selects both the transmission mode, i.e., either one- or two-hop transmission, and the desired user via two steps. A closed-form expression for the average achievable rate of the proposed scheduling is derived under two transmission modes with MU scheduling, and its asymptotic solution is also analyzed in the limit of large number of mobile stations. Based on the analysis, we perform our two-step scheduling algorithm: the transmission mode selection followed by the user selection that needs partial feedback for instantaneous signal-to-noise ratios (SNRs) to the base station. We also analyze the average SNR condition such that the MU diversity gain is fully exploited. In addition, it is examined how to further reduce a quantity of feedback under certain conditions. The proposed algorithm shows the comparable achievable rate to that of the optimal one using full feedback information, while its required feedback overhead is reduced below half of the optimal one.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.6
• /
• pp.245-252
• /
• 2013

We developed a system which supports the functions of real-time evaluation and feedback for smart learning. The system is consisted of an application for tablet PC and smart phone and the server, and the client exchanges data with the server through wireless communication. Whereby, the proposed system enabled realtime interaction and feedback between learner and teacher or between learners. As a result, the instruction for each learner's level is available using the system, and then it could enhance the level of academic achievement and learning interest.

• The Journal of Korean Association of Computer Education
• /
• v.16 no.3
• /
• pp.31-39
• /
• 2013

We developed a smart learning system by using the 'bring your own device' concept, which means the policy of permitting teacher and learners to bring personally owned mobile devices such as laptops, tablets, smart phones, etc. and applied the system to school classes. In addition, we analyzed the learner's satisfaction related to interfaces, interactions, applications, technical support, and evaluation areas. The evaluation system consists of App program for tablet PC's and smartphones, web program for desktop PC and electronic teaching desk, and server program for evaluation and database. Because all the teaching materials, feedback data and evaluation materials about learners are stored on the server, students can receive the necessary data through real-time feedback using their smartphones and desktop PC's. As a result, it could increase educational achievement with interest in learning.

• Sleep Medicine and Psychophysiology
• /
• v.9 no.1
• /
• pp.61-67
• /
• 2002

Objectives: This study is aimed at measuring psychophysiological responses using a biofeedback system in healthy people to obtain basic normative data for biofeedback research and treatment. Methods: Ninety-six healthy volunteers (55 males and 41 females : average age $30.4{\pm}8.0$) without any history of major medical or psychiatric illnesses participated in this study. Psychophysiological responses were assessed using the ProComp+ and BioGraph program (ver. 2.1) with regard to forearm and frontal electromyography (EMG), electrodermal response (EDR), and skin temperature. They were measured in 3 phases (baseline, stress, and recovery phases), respectively. Beck depression inventory and Spielberger state and trait anxiety inventory were used to measure mood states. We compared psychophysiological responses according to age and gender differences, respectively and examined the relationship between mood states and psychophysiological measures. Results: People in their twenties showed higher EDR levels in the 3 phases than those of other age groups. Female subjects showed higher frontal EMG levels in the 3 phases compared with male subjects. There was no significant correlation between biofeedback measures and mood states in these subjects. Conclusion: We present normative data of psychophysiological responses measured by a biofeedback system in healthy people. These results suggest that gender and age should be considered as important variables in assessing psychophysiological responses using a biofeedback system.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.1
• /
• pp.129-137
• /
• 2016

In the present study we verified performance of feed-forward control algorithm using short term prediction of ship motion information by taking advantage of developed numerical simulation model of FPSO motion. Up until now, various studies have been conducted about thrust control and allocation for dynamic positioning systems maintaining positions of ships or marine structures in diverse sea environmental conditions. In the existing studies, however, the dynamic positioning systems consist of only feedback control gains using a motion of vessel derived from environmental loads such as current, wind and wave. This study addresses dynamic positioning systems which have feedforward control gain derived from forecasted value of a motion of vessel occurred by current, wind and wave force. In this study, the future motion of vessel is forecasted via Brown's Exponential Smoothing after calculating the vessel motion via a selected mathematical model, and the control force for maintaining the position and heading angle of a vessel is decided by the feedback controller and the feedforward controller using PID theory and forecasted vessel motion respectively. For the allocation of thrusts, the Lagrange Multiplier Method is exploited. By constructing a simulation code for a dynamic positioning system of FPSO, the performance of feedforward control system which has feedback controller and feedforward controller was assessed. According to the result of this study, in case of using feedforward control system, it shows smaller maximum thrust power than using conventional feedback control system.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.2
• /
• pp.445-453
• /
• 2018

The purpose of this study was to analyze the effect of acute respiratory training feedback upon a change on HRV-Autonomic nervous system in middle-aged women. The research subjects were totally 24 middle-aged women(40-60 years old), were randomly allocated 12 people to the respiratory training group and 12 people to the control group, and then were carried out the acute respiratory training. The feedback exercise in the respiratory training group was conducted for totally 15 minutes. Following the 10-minute breath awareness training according to the expert's guidance, the 5-minute autonomous breathing exercise was implemented. The data analysis was carried out Repeated Measures ANOVA with SPSS WIN 20.0. The conclusions that were obtained through this are as follows. The middle-aged women got significantly higher in SDNN, RMSSD, LF, HF after the acute respiratory training. Compared to the control group. the respiratory training group was indicated to have gotten higher significantly in SDNN, RMSSD, LF, HF. Mean HR and LF/HF were not shown a significant difference in both the main effect of group & period and the interaction effect of group & period. Above of a result the acute respiratory training feedback is effective for SDNN, RMSSD, sympathetic activity, parasympathetic activity in the middle-aged women. Thereby, the respiratory training program improves autonomic nervous system, being considered to be possibly expected the effective value of exercise intervention available for relieving stress and recovering autonomic dysfunction in the middle-aged women.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10a
• /
• pp.380-382
• /
• 1998

ABR 은 ATM의 서비스 중에서 가장 최근에 추가된 것으로서 트래픽 소스의 전송률을 제어하기 위해서 피드백 메커니즘을 사용한다. ABR 서비스의 성능은 스위치를 통해서 피드백되는 RM 셀에 의해서 결정적인 영향을 받는다. ATM 표준에는 EPRCA, CAPC, ERICA 등의 알고리즘을 다루고 있다. 하지만 이러한 스위치 알고리즘에 대한 성능평가 및 분석 은 자세히 이루어지지 않고 있다. 본 논문에서는 현재 사용중인 ABR 스위치 알고리즘 중 단순히 큐의 길이에 위해 폭주를 판단하는 EPRCA 방법에 대해서 자세히 분석하고 EPRCA 의 단점을 극복하기 위해서 큐의 길이뿐만 아니라 새로운 변수 즉 평균 분산 및 표준편차을 이용해서 각 송신원의 공정성을 높이고 시스템의 효율성을 증대시키는 방안을 제시한다.