• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1294-1297
• /
• 2003

With the development of medical field, many kinds of operations have been performed on human articulation. Arthroscopic surgery, which has Irrigation Pumping System for security of operator vision and washing spaces of operation, has been used for more merits than others. In this paper, it is presented that the research on a reliable control algorithm of the pumping system instrument for arthroscopic surgery. Before clinical operation, the flexible artificial articulation model is used for realizing the model the most same as human's and the algorithm has been exploited for it. This system is considered of the following; limited sensing point, dynamic effect by compliance, time delay by fluid flow and so on. The system is composed with a pressure controller, a regulator for keeping air pressure, an airtight tank that can have distilled water packs, artificial articulation and a measuring system, and has controlled by the feedback of pressure sensor on the artificial articulation. Also the system has applied to Smith Predictor for time delay and the parameter estimation method for the most suitable system with both the experiment data and modeling. In this paper, the pressure error that is between an air pressure tank and an artificial articulation was measured so that the system could be presumed and then the controller had developed for performing State-Feedback. Finally, the controller with a real microprocessor has realized. The confidence of system can be proved by applying this control algorithm to an artificial articulation experiment material.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.15 no.2
• /
• pp.134-142
• /
• 2008

Purpose: This study was done to identify satisfaction with the method of evaluating practical skills in fundamental nursing through cellular phone animation self-monitoring and feedback. Method: The participants were 163 first-year student nurses. Data were collected from October 1 to 5 2007 using a structured questionnaire. Results: The average score for satisfaction was 3.65(${\pm}.69$) and the highest score was for the item, "I was pleased to have the opportunity of relearning by looking back at my behaviors through self monitoring" with 4.05(${\pm}.89$). The average score for dissatisfaction was 3.23(${\pm}.90$) and the highest score was "I memorized only orders according to the checklist" with 3.65(${\pm}.97$). The practical tests method showed a significant difference according to motivation for application to college of nursing (F=3.11, p=.047). There was a significant positive correlation between practical education satisfaction and test method (r=.363, p=.000). Conclusion: These findings show that there is a need to develop strategies to improve practical test methods for student nurses.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.2
• /
• pp.26-38
• /
• 1994

We demonstrate a repeatless transmission of 2.5 Gbps digital signal over 98 km opticla filbers using optical transmitter and optcial receiver which are designed and implemented using commercially available devices. The optical transmitter is realized by using a distributed feedback(DFB) laser. Temperature of the laser is thermoelectrically stabilized and the output optical power is also stabilized by using negative feedback. The output power of the transmitter is 0 dBm. The optical receiver consists of an InGaAs avalanche photodiode, a preamplifier. an automatic gain control amplifier, and a clock/data regenerator. We find an optimum decision threshold that gives the best receiver sensitivity form the measured V curve. The best sensitivity is -35.5dBm( BER-1*10S010T, PRBS=2S023T -1 ) and the overload power is -9 dBm. Finally, we achieve error free optical transmission with 98 km optical fibers. The exinction ration penalty of 2 dB. the chromatic dispersion penalty of 1 dB, and the total power penalty of 3.0 dB are measured. These results satisfy CCITT recommendation.

• Journal of Distribution Science
• /
• v.13 no.10
• /
• pp.35-44
• /
• 2015

Purpose - This study focuses on the voluntary performance of franchise customers as a result of inherent social motives. It examines the interplay between traits and motives, and their influence on customer citizenship behavior (CCB). Research design, data, and methodology - Empirical evidence from the responses of 288 university students, validates that individual traits are related to social motives, which provides a basis for CCB. The results suggest that social motives do influence an individual's intention to provide feedback, advocate, help, or tolerate. Structural Equation Modeling using AMOS 22 was employed to test the concept. Results - This research illustrates that extraversion has a dominant influence on affiliation motive, and agreeableness is a strong predictor of the altruism motive among franchise customers. Conclusion - All three traits have positive influence on the power motive. Power and altruism motives were found to be the main determinants of CCB in a social setting. The power motive was a better predictor of advocacy and tolerance. The altruism motive significantly predicted helping and tolerance. Feedback was only positively predicted by the affiliation motive.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.6
• /
• pp.102-113
• /
• 1996

An experimental and theoretical study on a pneumatic servo system has been conducted using on-off valves and a pneumatic cylinder. A V/I converter has been designed for rapid rising and falling of the solenoid current, which significantly improves the positioning accuracy and settling time of the servo system by shortening the valve opening time. Pulse width modulation was modified to operate on-off valves effectively. A state feedback controller which feeds back position, velocity and acceleration is used to control the system. The influence of controller gains on the system performance is studied to develop a scheme that automatically adjusts the gains using fuzzy logic theory. It is shown experimentally that the proposed fuzzy logic tuner works satisfactorily. A new method for measurements of valve effective areas is proposed, and a partially polytropic model is applied to simulation of the pneumatic system. Simulated results show good agreement with experimental data.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.2A
• /
• pp.140-146
• /
• 2004

In this paper we proposed the reducing method of feedback information for transmitting of adaptable data rate in multi-user OFDMA/FDD systems. In order to transmit downlink channel information to Base-Station(BS) through the limited uplink control channel, the proposed algorithm exploits the channel variation level which describes the similarity among the adjacent clusters and uses just one modulation and coding scheme(MCS) level representing channel information of all clusters'. We investigated the performance in single cell environment. It has a similar overhead for feedback information with conventional algorithm and has better performance in that bandwidth efficiency and outage probability than the conventional algorithms.

• Proceedings of the KIEE Conference
• /
• 1990.07a
• /
• pp.532-534
• /
• 1990

We suggest a new energy function that improves the area complexity of the Hopfield Crossbar Network. Through converting data representation to an encoded format, we reduce the number of nodes of the network, and thus reduce the entire size. We apply this approach to the layer assignment problem, and use the modified delayed self-feedback Hopfield Network. Area complexity of the existing network for layer assignment ploblem is improved from O( $N^2L^2$ ) to O($N^2$(log L)$^2$).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.9
• /
• pp.4242-4263
• /
• 2017

Multi-User Multiple-Input Multiple-Output (MU-MIMO) technology has recently attracted significant attention from academia and industry because of it is increasingly important role in improving networks' capacity and data rate. Moreover, MU-MIMO systems for the Fifth Generation (5G) have already been researched. High Quality of Service (QoS) and efficient operations at the Medium Access Control (MAC) layer have become key requirements. In this paper, we propose a downlink MU-MIMO MAC protocol based on adaptive Channel State Information (CSI) feedback (called MMM-A) for Wireless Local Area Networks (WLANs). A modified CSMA/CA mechanism using new frame formats is adopted in the proposed protocol. Specifically, the CSI is exchanged between stations (STAs) in an adaptive way, and a packet selection strategy which can guarantee a fairer QoS for scenarios with differentiated traffic is also included in the MMM-A protocol. We then derive the expressions of the throughput and access delay, and analyze the performance of the protocol. It is easy to find that the MMM-A protocol outperforms the commonly used protocols in terms of the saturated throughput and access delay through simulation and analysis results.

• Journal of Korean society of Dental Hygiene
• /
• v.20 no.4
• /
• pp.469-478
• /
• 2020

Objectives: The aim of this study was to investigate the impact of oral hygiene education provided by dental hygienists in patients with dental implants. Methods: Data were obtained from a survey that involved 300 patients who had one or more dental implants. Based on the calculated sample size (n = 274), 300 questionnaires were used for further analyses. Results: The patients who received oral hygiene education had higher levels of satisfaction after dental implant surgery (p<0.05). Patients who had repeated educational sessions, in the form of interactive or hands-on sessions or lectures, with continuous feedback had higher scores for oral hygiene maintenance (p<0.05). Conclusions: This study indicated that patients who received oral hygiene education, in the form of interactive or hands-on sessions or lectures, with continuous post-educational feedback were better at maintaining oral hygiene.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.4
• /
• pp.443-450
• /
• 2014

This paper presents a 20-Gb/s optical receiver circuit fabricated with standard 65-nm CMOS technology. Our receiver circuits are designed with consideration for parasitic inductance and capacitance due to bonding wires connecting the photodetector and the circuit realized separately. Such parasitic inductance and capacitance usually disturb the high-speed performance but, with careful circuit design, we achieve optimized wide and flat response. The receiver circuit is composed of a transimpedance amplifier (TIA) with a DC-balancing buffer, a post amplifier (PA), and an output buffer. The TIA is designed in the shunt-feedback configuration with inductive peaking. The PA is composed of a 6-stage differential amplifier having interleaved active feedback. The receiver circuit is mounted on a FR4 PCB and wire-bonded to an equivalent circuit that emulates a photodetector. The measured transimpedance gain and 3-dB bandwidth of our optical receiver circuit is 84 $dB{\Omega}$ and 12 GHz, respectively. 20-Gb/s $2^{31}-1$ electrical pseudo-random bit sequence data are successfully received with the bit-error rate less than $10^{-12}$. The receiver circuit has chip area of $0.5mm{\times}0.44mm$ and it consumes excluding the output buffer 84 mW with 1.2-V supply voltage.