• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.5
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• pp.17-23
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• 1995

A numerical analysis on engine coolant is made by the use of FVM based general purpose 3 dimensional Navier-Stokes solver, TURB-3D. Numerical solutions are verified by comparison with the experimental data of Lotus model. The results show a good qualitative as well as quantitative comparison. Coolant flow rate control is attempted through adjusting the cross section area of passage base on the results of an original coolant passage. It is concluded from the results that the flow rate control is possible as attempted, and thus can be used in the real engine design.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.313-319
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• 2000

As the interest of flexible manufacturing systems and computer integrated manufacturing systems increase, the distribution of centralized control systems using industrial control networks is getting more attention. In this paper, we investigate the rate-based traffic control of industrial control networks to improve the performance regarding the throughput, fairness, and error rates. Especially, we consider the protocol of Lon-$Works^{(TM)}$ which consists of all OSI 7-layers and supports various communication media at a low cost. Basically, the proposed rate-based traffic control system is closed loop by utilizing the feedback channel errors, which shows improved performance when compared with other industrial control networks commonly operated in open loop. To this end, an additional network node called monitoring node is introduced to check the channel status without increasing the channel load. The Proposed control loop is in effect whenever the feedback channel error becomes greater than an admittable value. We demonstrate the improved performance of the controlled network system in view of throughput and fairness measures by implementing the lab-scale network system based on LonWorks and through the experimentation upon it.

• Journal of Korean society of Dental Hygiene
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• v.15 no.3
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• pp.363-369
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• 2015

Objectives: The purpose of this study is to investigate the cognition and practice of infection control in the dental hygienists. Methods: A self-reported questionnaire was completed by 220 dental hygienists in Busan and Gyeongnam from August 1 to 31, 2014. The questionnaire was adapted from Nam. The questionnaire consisted of four questions of the general characteristics of the subjects, two questions of infection control factors, four questions of clinic environment, 50 questions of awareness of infection control, and 50 questions of infection control practice. Cronbach's alpha in the awareness of infection control was 0.958 and that in infection control practice was 0.950. Results: The dental hygienists in the large scale hospitals tended to have higher score of cognition and practice of infection control thatn those in the small scale hospitals(p<0.001). Small scale hospitals tended to have lower infection rate than the large scale hospitals. The education for the infection control guideline reduced the infection prevalence rate. Conclusions: In order to reduce the infection prevalence rate, it is necessary to educate the dental hygienists continuously and to provide the infection control guideline to the dental clinics.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.534-542
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• 1999

A sell-designed rate control strategy can improve overall picture quality for video transmission over a constant bit rate channel and the rate control method is not a normative part of MPEG-video standard, the performance of MPEG video codec can be quite different depends on how to implement the rate control scheme. The rate control scheme proposed in MPEG show good results when scene changes is not occurred. But it has weakness that it does not properly handle scene-changed pictures. Therefore picture quality after scene change is deteriorated, and possibility of overflow occurrence becomes high. In this paper, a new method for detection of scene change occurrence using local variance and a new determination scheme for adaptive quantization parameter, mqunt, which can consider local characteristic of an image by using previously computed the local variance from the scene change detection part are proposed. IN addition, and adaptive rate control scheme which can handles scene changed picture very efficiently by scene-changed picture is proposed. Computer simulations are performed to verify the performance of the proposed algorithm. The suggested detection algorithm precisely detected scene change. And the proposed rate control scheme shows better rate control performance as compared with that of the conventional MPEG scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.833-841
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• 1997

In this paper, the hybrid LB-TJW(Leaky Bucket-Triggered Jumping Window) algorithm for multimedia traffic control is proposed and its performance is evaluated and analyzed. Its architecture is composed of the peak bit rate controller and the average bit rate controller. Generally, the cell which violates the peak bit rate is discraded in LBalgorithm, and the average bit rate of JW or TJW algorithm is better than that of LB algorithm. However, the hybrid LB-TJW algorithm passes it though the network if the cell does not violate the peak bit rate. If the cell violates the peak bit rate, the hybrid LB-TJW algorithm passes it to the average bit rate controller which perforithm to monitor the average bit rate of input traffic. The TJW algorithm monitors the cell that violates the average bit rate. If the cell does not violate the average bit rare, the LB-TJW algorithm passes it through the network. As simulation results, the cell loss rate and the buffer size of the LB-TJW algorithm is reduced to half as much as those of LB algortihm.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.307-320
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• 2017

The objective of this study is to identify the effectiveness of ESC(Electronic Stability Control) based on a meta analysis technique. Accident Rate, Fatal Crash Rate, Loss of Control Crash Rate were set as indexes of traffic safety evaluation. Also, reviews on the effectiveness of ESC were collected using keyword, 'ESC'. As a result, the Effect size of accident rate odd ratio was 0.90. When ESC system was applied on vehicles, accident rate decreased by 10%. Also, the Effect size of fatal crash rate odd ratio was 0.64. When ESC system was applied on vehicles, fatal crash rate decreased by 36%. Lastly, the Effect size of loss of control crash rate odd ratio was 0.73. When ESC system was applied on vehicles, loss of control crash rate decreased by 27%. The outcome of this study would be effectively used for developing polices and regulations for ESC installation obligation of commercial vehicles.

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.358-366
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• 2010

In the wireless network the congestion and delay occurs mainly when there are too many packets for the network to process or the sender transmits more packets than the receiver can accept. The congestion and delay is the reason of packet loss which degrades the performance of multimedia streaming. This paper proposes a novel transmission rate monitoring-based optimization mechanism to optimize packet loss and to improve QoS. The proposed scheme is based on the trade-off relationship between transmission rate monitoring and overhead monitoring. For this purpose this paper processes a source rate control-based optimization which optimizes congestion and delay. Performance evaluated RED, TFRC, and the proposed mechanism. The simulation results show that the proposed mechanism is more efficient than REC(Random Early Detection) mechanism and TFRC(TCP-friendly Rate Control) mechanism in packet loss rate, throughput rate, and average response rate.

• The Journal of Internal Korean Medicine
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• v.3 no.1
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• pp.23-32
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• 1986

As a result of administration of Coptidis Rhizoma extract and Zingiberis Rhizoma extract to Rat and Rabbit, its effect to the Gastric Juice Volume, Acidity, Pepsin out put of Rat and the movement of Intestine, Pulse Rate of Rabbit was as follows; 1. In the secretion of Gastric Juice, the Juice Volume in Coptidis Rhizoma administered group in contrast to Control Group, has increased in 30mg the increasing rate 21.4%, and has decreased in 300mg the decreasing rate 113.9%. But the Juice Volume in Zingiberis Rhizoma administered group has all decreased in 12, 30, 60, 120mg, and has remarkably decreased in 60mg the decreasing rate 62.9%. 2. The Gastric Acidity in Coptidis Rhizome administered group, in contrast to Control Group, has increased in 30, and 75mg, but no significant value, and has decreased in 300mg the decreasing rate 104.7%. But the Gastric Acidity in Zingiberis Rhizoma administered group has all decreased in 12, 30, 60 120mg, and has remarkably decreased in 60mg the decreasing rate 105.6%. 3. The Pepsin out-put in Coptids Rhizoma administered group, in contrast to Control group, has increased in 30mg the increasing rate 30.3%, and has decreased in 150, 300mg, no significant value. But the Pepsin out-put in Zingiberis Rhizoma administered group has all decreased in 12, 30, 60, 120mg, and has remarkably decreased in 60mg the decreasing rate 86.4%. 4. In the movement of Intestine, the contraction Coptidis Rhizoma administered group, in contrast before the administration, has increased in 12mg, but has begun to decrease in 30mg, and has remarkably decreased in 70mg. The contraction in Zingiberis Rhizoma administered group, in contrast before the administration, has all increased in 30, 60, 120mg. 5. In Pulse Rate, the pulsation, in contrast to Control group after 60, 120 180, 240min. has decreased in Coptidis Rhizoma administered group, and has increased in Zingiberis Rhizoma administered group, but no significant value.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.100-102
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• 1998

This paper presents technique to control blower at constant air volume rate using V/F Control. Especially, this control method have not pressure sensors to measure because of using torque-speed relation based on the fan laws. Therefore, this technique is very simple and practical.

• Journal of Korea Game Society
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• v.10 no.1
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• pp.35-45
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• 2010

This study sets a hypothesis on that the use of input control devices, which are similar to what we experience in real life, to control activities in games increases players' immersion rate, and compares general input control devices with dedicated input control devices in order to show appropriate results. Accordingly the process of the study is derived and the hypothesis is substantiated by understanding the relationship between game controlling activities and immersion rate. Overall satisfaction survey result on the use of dedicated devices shows that most players responded that they felt immersed enough in games when used dedicated devices and were highly satisfied. The use of the dedicated devices had positive impact on the increase of immersion rate in general. In order to increase immersion rate with controlling activities in games, the use of input control devices that are easy to handle and enable precise control is required, which shows that it will bring more fun and more increased immersion rate.