• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.3
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• pp.19-27
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• 2011

Due to the growth of optical fiber network technologies, most networks recently support several tens of Gb/s bandwidth. UDT(UDP-based Data Transfer protocol) is an optimized protocol for bulk data transmission on the network, which has the high bandwidth and long delay time. It periodically controls the sending rate on the fixed sync-interval, 0.01 sec. Here, if the network traffic status varies quickly, available network bandwidth is not able to be properly utilized in-between the sync-intervals. In this paper, we propose an adaptive rate control method with considering the network traffic status in-between the sync-interval periods. The network traffic status is determined based on the RTT variances. With dividing the network status into four classes, the proposed method performs a new rate control by adjusting the inter-packet sending period for a corresponding class. As a simulation result, the proposed method improves the message delivery throughput as well as stability than that of the existing UDT Protocol.

• Journal of Biomedical Engineering Research
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• v.29 no.6
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• pp.443-450
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• 2008

The purpose of this study is to measure both ECG and BCG(Ballistocariograph) signal of a subject on moving or resting wheelchair and detect the heart rate and respiratory rate and transmit an event message to remote server on emergent situation. To acquire ECG and BCG data, amplifier circuits were composed to be suitable for their characteristics. The output signals were converted to digital data and stored in bio-signal archiving media(SD card). CDMA module was used to transmit the event data on ECG electrode detachment and the received data was monitored by the developed C# application program. 5 volunteers participated in the experiment to evaluate the validity of the developed device. When the event occurs in each subject, 48 Kbyte data, stored for 32 seconds from that point, was transmitted to remote server through CDMA cellular phone network correctly. The received data of ECG, BCG, and 3-axial acceleration could be archived in server and the heart rate and respiratory rate could be measured and analyzed. The developed device in this study could acquire the ECG and BCG data of subjects on wheelchair simultaneously and measure their heart rate and respiratory rate. In addition, event data was verified to be transmitted to remote server without any errors.

• Archives of design research
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• v.13
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• pp.15-24
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• 1996

No mater how brilliant brain a man has, as time goes by, it is certain to fall into a lapse of memory phenomenon in according to cease to exist as a matter of course. But as previously stated, there is no room for douby, if we make advertising information for being changed into a sign which is to be treated easily and simplified, we can easily memory and withdraw it. In other words, the information is to be coded simpler, the memory and recollection of it is to be easier as wll as we can raise the precision rate. Good many advertising today, it appears, try to raise the acknowlegement rate with shock of good-sized and exposure frequency. In this advertising form, we can aspire to the intention of advertiser to try to get lapse of the message of advertising. Of course, even if it cannot be an index of every advertising information called simplified memory and recollection rate, it should be emphasized that it cannot but have something to do with the consumer's memory. Which to be obtained by invested advertisement. As for it, there are so many things to be taken charge of a lots of content by graphic designer: to be obtained mental distribution of resources inconnected with a desire of consumer, to be converted memory information into being less than that and treated easier, and to be correlated the memory information with the previously known things.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.139-143
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• 2019

Measurement of flow rate is required in various fields. Water meters are often used at home, and flow meters are used in water and sewage plants, petrochemical industries and so on.. A system is needed to monitor the flow rate in real time and notify immediately when flow rate is abnormal. Recently, with the development of the IoT it is possible to construct such devices at low cost. WeMos can be programmed with Arduino IDE as a mini wifii IoT module. The flow sensor can output a digital pulse proportional to the flow rate. In this paper, we developed the flow monitoring and warning system using WeMos and IoT technology. When the system operates, it calculates the flow rate, sends the value as JSON format to the server, monitors the flow rate as graph from the remote with the smartphone. We also implement the system to promptly send alert message to the smart phone using Pushbullet when the flow rate is abnormal.

• Journal of KIISE
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• v.44 no.12
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• pp.1296-1306
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• 2017

Recently, as the number of Internet of Things users has increased, IETF (Internet Engineering Task Force) has released the CoAP (Constrained Application Protocol). So Internet of Things have been researched actively. However, existing studies are difficult to adapt to streaming service due to low transmission rate that result from buffer underflow. In other words, one block is transmitted one block to client's one request according to the internet environment of limited resources. The proposed scheme adaptively adjusts the rate of CON(Confirmable) message among all messages for predicting the exact network condition. Based on this, the number of blocks is determined by using buffer occupancy rate and content download rate. Therefore it improves the quality of user experience by mitigating playback interruption. Experimental results show that the proposed scheme solves the buffer underflow problem in Internet of Things streaming environment by controlling transmission rate according to the network condition.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.121-129
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• 2012

In this paper, we proposed WBAN system model to management an application that requires low rate data transfer in IEEE 802.15.4. We have to use different wireless sensor network technology to transfer different date rate and emergency message in medical application service. A suitable system model for WBAN and a WBAN MAC protocol in order to solve these existing system problems are proposed. Firstly, the priority queuing was applied to contention access period, and the system model which could guarantee transmission of a MAC command frame was proposed. Secondly, the MAC frame was newly defined to use the system model which was proposed above. Thirdly, WBAN CSMA/CA back-off algorithm based on data transmission rate was proposed to enhance data throughput and transmission probability of the data frame which does not have priority in the proposed WBAN system. The proposed algorithm is designed to be variable CSMA/CA algorithm parameter, depending on data rate. For the evaluation of WBAN CSMA/CA algorithm, we used Castalia. As a result of the simulation, it is found that the proposed system model can not only relieve loads of data processing, but also probability of collision was decreased.

• Korean Journal of Health Education and Promotion
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• v.23 no.2
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• pp.77-89
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• 2006

Objectives: Recent studies have shown that tailoring to women's individual beliefs and stage of cancer screening adoption increase the probability that cancer screening will ensue. To identify variables associated with cancer screening behavior, many studies for cancer screening have used the Transtheoretical Model(TTM). This study was carried out to identity the cognitive and behavioral factors associated with breast cancer screening by stages of change among women, forties aged. Methods: Building on the TTM constructs, we collected the data to test the association with cognitive and behavioral factors for breast cancer screening by stage of change among women, forties aged (N=232), using the self-reported questionnaire. The stages of change were grouped according to screening participation and intention for breast cancer as precontemplation, contemplation, preparation, action, and maintenance. We found out the association between breast cancer screening and cognitive and behavioral factors, and testified the difference between stages of change by chi-square test, one-way ANOVA, and multiple comparison analysis(Duncan test). Results: Analyses of 232 women showed that participation on mammography was 68.1% within lifetime and 46.1% within last 2 years, and we found out the association with breast cancer screening participation, intention and cognitive-behavioral factors. The stages of change based on participation and intention were different from the decisional balance, the screening attitude, and the self-efficacy(p<0.01). The decisional balance was differ from stages of change because the difference on opinions about pros(positives) and cons(negative) were likely to significant by stages of change(p<0.05, p<0.01). Conclusion: To increase the screening rate for breast cancer, it should be developed the tailored message and recommend guideline. And the tailored message should be designed to increase the pros of breast cancer screening(mammography) and to decrease the cons, and considered the woman's stage of adoption.

• Korean Journal of Health Education and Promotion
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• v.22 no.2
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• pp.97-110
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• 2005

Objectives: Recent studies have shown that tailored messages for cancer screening to the beliefs and stage of cancer screening behavior of individual women increases the take-up probability. Many studies on cancer screening have used the Transtheoretical Model (TTM) to identify variables associated with cancer screening behavior. This study was carried out to identify the cognitive-behavioral factors associated with stomach cancer screening among women aged 40 years and over, and to develop and evaluate a tailored educational program for stomach cancer screening by stages of change. Methods: Building on the TTM constructs, we conducted a quasi-experimental study(N=283) to test the effectiveness of a tailored educational program for endoscopic stomach cancer screening. We carried out pre and post tests in the experimental group(N=162) and the control group(N=121), and the experimental group was subdivided into an on-line group(N=81) and an off-line group(N=81) by educational methodology using e-mail and the postal service. We used the chi-square test, trend test, and paired t-test to test the effectiveness of the program for stomach cancer using a tailored stage-matched messages. Results: To examine the effectiveness of the program for stomach cancer screening by the tailored stage-matched messages, the stage-matched materials were offered to the experimental group(N=162) four times for 4 weeks. The stage-matched materials consisted of the four types for stomach cancer. The tailored message was effective in changing the cognitive-behavioral factors, such as experience process, behavior process, con opinion for stomach cancer, self-efficacy, and the behavioral stages for stomach cancer screening. The stomach cancer screening adherence was higher for the stage-matched materials using postal mail than for those using e-mail. Conclusion: To improve the stomach cancer screening rate, the use of tailored messages for stomach cancer screening will be generated using an expert system. Therefore the implementation of tailored educational program will be supported a partnership between public and private health organizations and increasing awareness of the necessity of community-based interventions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.11
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• pp.932-938
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• 2017

Particle-in-cell method which blends Eulerian grids and Lagrangian particle is utilized to solve simplified hall-effect thruster. Since this study individually tracks not only neutrons and ions but also electrons, message passing interface(mpi) scheme is adopted for parallel computer cluster. Helical movement of an electron cloud in constant magnetic field is validated comparing with an exact solution. A plasma in radial magnetic field and axial electric field in a reaction cylinder is established. Electrons do double helix movement and are well anchored in a cylinder. Ionization of neutrons by impact with high-speed electrons generates ion particles. They are accelerated by axial electric field, which forms a plume of a plasma-effect thruster.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.393-402
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• 2017

Just like terrestrial cellular networks, underwater cellular communication networks, which can manage the overall network resource by adaptively allocating backhaul resource for each base station according to its ingress traffic, are necessary. In this paper, a new resource allocation protocol is proposed for the underwater cellular communication network, allocating backhaul resource of a base station proportional to its ingress traffic to the base station. This protocol is classified into two types dependent upon allocation period: the resource allocation protocol with adaptive period and that with fixed period. In order to determine a proper resource allocation protocol, the performance of the two protocols, in terms of reception rate, message overhead, and latency is compared and investigated via simulation. As a result, the resource protocol with adaptive period outperforms that with fixed period; the resource allocation protocol with fixed period results in a maximum of $10^2$ order longer queueing delay as well as $10^2$ order greater message overhead than that with adaptive period.