• Journal of Institute of Control, Robotics and Systems
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• v.17 no.2
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• pp.190-197
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• 2011

In industrial distributed control systems, sensors collect data from the physical environment periodically and transmit them to the actuators, which process the control operations based on the received data. For the effective operation of the control systems, the data transmitted by the sensors has to be delivered to the actuators reliably within the deadline, and if the message reception rate of the actuators becomes lower than a threshold, then the performance of the control systems drops greatly. This paper suggests a message routing protocol to transmit periodic messages reliably in a distributed control system based on wireless sensor networks. For reliable message transmission, the proposed protocol selects a routing path whose end-to-end message reception rate is the highest before transmitting data messages. The proposed protocol has the capability of maintaining a target message reception rate for each flow. To maintain the required target reception rate, each destination monitors the actual message reception rate periodically and transmits a feedback message to the source if it drops below the target reception rate. On receiving the feedback message, the source tries to find a new path which can satisfy the target rate. The performance of the proposed protocol has been evaluated using simulation and compared with other protocols in terms of the message reception rate, the message delay and delay jitter, and so on. The simulation results show that the proposed protocol has a higher message reception rate and comparable message delay and delay jitter to other protocols. The simulation results also show that the proposed protocol has an ability to adapt well to the dynamic network traffic change.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.190-195
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• 2004

In this paper, Error rate performance of Convolution coded DS-CDMA 16 QAM signal is analyzed using selective combining diversity reception techniques and maximal ratio combining diversity reception techniques under the environments of Rician fading. With the results of analysis, maximal ratio combining diversity reception techniques provides the performance improvement of about 3-8[㏈] over selective combining diversity reception techniques for the good error performance lot data communication. And it is found that a synergistic performance improvement is show to both diversity reception and Convolution coding, techniques overcoming mobile wireless data communication channel environment.

• Journal of IKEEE
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• v.16 no.1
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• pp.7-14
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• 2012

In this paper, a reception rate of terrestrial digital TV broadcasting service is analyzed and a novel method which can estimate the broadcasting coverage rate more objectively and reliably than the existing method is proposed. Previous method measures the reception rate by means of electric field intensity measurement or subjective video quality assessment. Because of limited measuring points, it inherently has measurement error and cannot consider the viewer's receiving conditions in real-time. In order to consider the viewer's population and receiving environment, morphology which characterizes the viewer's receiving environment is extracted using household census data of National Statistical Office and the land cover map of Ministry of Environment. Using the extracted geographical morphology, the reception rate of terrestrial digital TV broadcasting service is calculated with Spectrum Management Intelligence System (SMIs). Proposed method can calculate the reception rate more objectively and reliably than the existing methods because it fully considers the viewer's receiving environments in real-time.

• Journal of the Korea Society of Computer and Information
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• v.7 no.4
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• pp.188-198
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• 2002

In this paper, we propose an active network to support reliable data transmission in the mobile ad-hoc network. The active network uses DSR(Dynamic Source Routing) protocol as its basic routing protocol, and uses source and destination nodes as key active nodes. For reliable improvement the source node is changed to source active node to add function that its buffer to store the last data with the flow control for data transmission per destination node. The destination node is changed to destination active node to add function that it requests the re-transmission for data that was not previously received by the destination active node with the flow control for data reception per source active node As the result of evaluation. we found the proposed active network guaranteed reliable data transmission with almost 100% data reception rate for slowly moving mobile ad-hoc network and with more 95% data reception rate, which is improvement of 3.5737% reception rate compared with none active network, for continuously fast moving mobile ad-hoc network.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1224-1228
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• 2010

The existing cluster-based routing protocols have some problems. Firstly, because of selecting cluster head at random, they occur a node concentration problem. Secondly, they have a low reliability for data communication due to the less consideration of node communication range. Finally, data communication overhead is greatly increased because of sending all sensor node information to sink node for constructing clusters. To solve these problems, we in this paper, propose a cluster-based routing protocol using message reception success rate. Firstly, to solve the node concentration problem, we design a cluster head selection algorithm based on node connectivity and devise cluster spliting/merging algorithms. Secondly, to guarantee data communication reliability, we use message reception success rate. Finally, to reduce data communication overhead, we use only neighbor nodes information at both cluster construction and cluster head selection.

• Korean Journal of Remote Sensing
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• v.15 no.3
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• pp.209-216
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• 1999

KITSAT-3, the third satellite of KITSAT series which has been developed for the last four and half years with purely Korean design and implementation technology, was launched successfully at last. All subsystems were tested and validated during the initial operation of the satellite. During the initaial operation phase, the Earth imaging camera on board KITSAT-3 acquisited several tens of scenes all over the world and transmitted the image data to ground station. The quality of images and the reliability of data transmission-reception system were tested qualititively and quantititively, respectively. In this paper, we summarize the camera, data handling, on-board memory, and image data transmission system of KITSAT-3 as well as the image receiving and archiving system in ground station. The error rate of image data transmission and reception was tested during the initial operation phase. The average data transmission error rate satisfied the initial requirement of less than 1%. The error rate will be reduced through the continuous work of test and stabilization of the ground system hardware.

• Korea Journal of Hospital Management
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• v.14 no.4
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• pp.149-162
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• 2009

The purpose of this study is to design strategic hospital service based on each hospital's features. For this study, an assessment was conducted by 398 in-patents of one university hospital located in Seoul. The self-questionnaires, which were investigated from Oct. 15th to 29th in 2008, compared central reception desk with ward reception desk in satisfaction and re-use rate of patients. The major results of this study are as follow. First, according to each reception desk user, they have different satisfaction of it. As for the staff kindness, admission procedure, discharge procedure and manner of staff, those made patients be gratified as well. Second, when it comes to the intention of re-use, there were no significant features between them. Only convenience in admission and discharge procedure, however, was an attractive factor for the recommendation. Third, this study found out the reasons for higher re-use rate of central reception desk users. Regarding service, they were contented with the time for test and treatment. As for the hospital service, they would like to re-use this hospital because of convenient steps of paying interim fee and getting certificates. Forth, this study found out the reasons for higher re-use rate of ward reception desk users. As a point of hospital service view, they responded that respected privacy, hospital facility and general service were good for staying. As for the manner of staff, they mentioned nurses and staff in charge and whole staff members were kind. When it comes to the procedures of patient management, steps of discharge and paying interim fee were convenience. In conclusion, the results of this study suggest that providing a ward reception desk service can boost the satisfaction and re-use rate of in-patients. Furthermore, this strategic management method would be good for not only cutting the moving line but also efficient in-patient care system. These results can be used for the strategic hospital marketing field, as well. Even though this study has a limitation of the targeted populations which were only in a ward reception desk running hospital, it can say that having competitiveness in satisfaction of hospital service is good for promoting and differencing each hospital. Consequently, whole general management system would be adjusted first for differencing each hospital; however, this sort of additional factor should be concerned as well. I expect that this study would give meaningful data for designing strategic and differencing marketing method to lots of hospitals.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.124-132
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• 2017

This paper describes the Around View Monitoring (AVM) system for hydraulic excavators that prevents the safety accidents caused by blind spots and increases the operational efficiency. To verify the developed system, experiments were conducted with its prototype. The experimental results demonstrate its applicability in the field with the following values: 7m of a visual range, 15fps of image refresh rate, 300ms of working information data reception rate, and 300ms of surface condition data reception rate.

• Journal of IKEEE
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• v.7 no.1 s.12
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• pp.63-71
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• 2003

In this paper, we propose an DSR(Dynamic Source Routing) protocol to support QoS for reliable data transmission in the mobile ad-hoc network. The proposed algorithm uses DSR protocol to support QoS as its basic routing protocol, and uses the nodes which are between source and destination nodes as key QoS support. Because of moving nodes there is some problem that is restricted reliable data transmission. For solve this problem, source node set up the QoS link with destination node. The nodes that are located at QoS link and find out loss of transmission path save the transmitting data packets. Those search a new transmission path to destination node and transmit the saved data packet to destination node. As the result of evaluation, we found the proposed QoS network guaranteed reliable data transmission with almost 100% data reception rate for slowly moving mobile ad-hoc network and with more 96% data reception rate, which is improvement of 3.7737% reception rate compared with none QoS network, for continuously fast moving mobile ad-hoc network.

• Proceedings of the Safety Management and Science Conference
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• 2002.05a
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• pp.121-127
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• 2002

In this paper, we propose traffic management support and evaluate the performance through simulation. We suggest traffic management routing protocol that can guarantee reliance according to not only reduction of the Network traffic congestion but also distribution of the network load that prevents data transmission. For performance evaluation, we analyzed the average data reception rate and network load, considering the node mobility. We found that in the mobile Ad Hoc networks, the traffic management service increased the average data reception rate and reduced the network traffic congestion and network load in Mobile Ad Hoc Networks.