• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.1
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• pp.12-22
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• 2000

This paper presents the window-based permit distribution scheme for efficient medium access control to support multiclass traffic in APON(ATM over passive optical network). The proposed MAC protocol considers the characteristics of QoS(Quality of Service) for various traffic classes. A periodic RAU(request access unit) in upstream direction, includes dedicative request fields for each traffic category within the request slot. The transmission of upstream cell is permitted by the proposed window-based spacing scheme which distributes the requested traffic into several segments in the unit of one spacing window. The delay sensitive traffic source such as CBR or VBR with the stringent requirements on CDV and delay, is allocated prior to any other class. In order to reduce the CDV, so that the permit arrival rate close to the cell arrival rate, Running-Window algorithm is applied to permit distribution processing for these classes. The ABR traffic, which has not-strict CDV or delay criteria, is allocated flexibly to the residual bandwidth in FIFO manner. UBR traffic is allocated with the lowest priority for the remaining capacity. The performance of proposed protocol is evaluated in terms of transfer delay and 1-point CDV according to various offered load. The simulation results show that our protocol has the prominent improvement on CDV and delay performance with compared to the previous protocol.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.24-35
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• 2012

In this paper, we propose a dynamic lane control scheme with a traffic predictor module and a rate controller for reconciling with commercial optical PHY modules in energy efficient optical Ethernet systems. The commercial high speed optical Ethernet system capable of 40/100Gbps employs 4 or 10 multiple optical transceivers over WDM or multiple optical links. Each of the transceivers is always turned on even if the link is idle. To save energy, we propose the dynamic lane control scheme. It allows that several links may be entirely turned off in a low traffic load and frames are handled on the remaining active links. To preserve the byte order even if the number of active links may be changed, we propose a rate controller to be sat on the reconciliation sublayer. The main role of the controller is to insert null byte streams into the xGMII of inactive lanes. For the PHY module, the null input streams corresponding to inactive lanes will be disregarded on inactive PMDs. It is very handy to implement the rate controller module with MAC in FPGA without any modification of commercial PHYs. It is very crucial to determine the number of active links based on the fluctuated traffic load, we provide a simple traffic predictor based on both the current transmission buffer size and the past one with different weighting factors for adapting to the traffic load fluctuation. Using the OMNET++ simulation framework, we provide several performance results in terms of the energy consumption.

• Journal of Animal Environmental Science
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• v.11 no.1
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• pp.11-16
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• 2005

The round bale wrappers are generally used for rice straw after the harvesting of low land rice by combine harvester. In this situation, the bale wrappers should be well adapted under the travelling over raised borders and temporary ditches in soft soil of narrow rice fields. The study was conducted to improve the performance of bale wrapper through the new design for compact size, lowered gravity center and lowered power consumption. The prototype of round bale wrapper had been designed and assembled to tractor with three point hitch mounted. The machine type is one roll driving system with one roll for rotating and one roll for wrapping. The driving torque and work performance of the machines were measured and analysed. The torque requirement of the prototype and conventional type was 6kgf-m and 12kgf-m, respectively. The prototype shaved less friction resistance between bale driving roll and round bale. and the power requirement can also be reduced from 12kgf-m in the conventional to 6kgf-m in the prototype. The work efficiency of the new bale wrapper was $45\%$ higher than the conventional wrapper, and the working cost of the prototype can be reduced $17\%$ than that of the conventional.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.819-828
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• 2007

Two experiments were conducted to observe the effects of direct fed microbials on metabolic characteristics in sheep and milking performance in dairy cows. A metabolic trial with four ruminally cannulated sheep(60±6kg) was conducted in a 4×4 Latin square design to investigate the supplementation effects of Saccharomyces cerevisiae, Clostridium butyricum or mixed microbes of S. cerevisiae and C. butyricum on ruminal fermentation characteristics and whole tract digestibility. Sheep were fed 1.25 kg of total mixed ration(TMR, DM basis) supplemented with S. cerevisiae (2.5g/day), C. butyricum (1.0g/day) or its mixture(S. cerevisiae 1.25g/day+C. butyricum 1g/day), twice daily in an equal volume. But control sheep were fed only TMR. A feeding trial with 28 lactating Holstein cattle was also conducted for 12 weeks to investigate the effects of the same microbial supplements as for the metabolic trial on milking performance. The cows were fed the TMR(control), and fed S. cerevisiae(50g/day), C. butyricum(15g/day) or its mixture (S. cerevisiae 25g/day + C. butyricum 7.5g/day) with upper layer dressing method. Total VFA concentration and the digestibility of whole digestive tract in the sheep increased by supplementation of S. cerevisiae, C. butyricum or their combined microbials compare to control group. The proportion of propionic acid at 1h(P<0.039) and 3h(P<0.022) decreased by supplementation of S. cerevisiae while tended to increase acetic acid proportion at the same times. Daily dry matter intake(DMI) was not influenced by the microbial treatments, but milk yield(P<0.031) and feed efficiency(milk yield/DMI, P<0.043) were higher for the cow received C. butyricum than those for other treatments. The milk fat content was higher (P<0.085) when cows fed S. cerevisiae(4.11%) than that fed the control (4.08%), the diets with C. butyricum (3.85%) and the microbial mixture. Based on the results obtained from the current experiments, supplementation of C. butyricum or mixture with S. cerevisiae might be increased milk fat content and milk productivity of lactating daily cows. (Key words:Saccharomyces cerevisiae, Clostridium butyricum, Fermentation characteristics,

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.409-414
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• 2008

In mobile ad hoc networks, most of on demand routing protocols such as DSR and AODV do not deal with traffic load during the route discovery procedure. To solve the congestion and achieve load balancing, many protocols have been proposed. However, the existing load balancing schemes has only considered avoiding the congested route in the route discovery procedure or finding an alternative route path during a communication session. To mitigate this problem, we have proposed a new scheme which considers the packet bursting mechanism in congested nodes. The proposed packet bursting scheme, which is originally introduced in IEEE 802.11e QoS specification, is to transmit multiple packets right after channel acquisition. Thus, congested nodes can forward buffered packets promptly and minimize bottleneck situation. Each node begins to transmit packets in normal mode whenever its congested status is dissolved. We also propose two threshold values to define exact overloaded status adaptively; one is interface queue length and the other is buffer occupancy time. Through an experimental simulation study, we have compared and contrasted our protocol with normal on demand routing protocols and showed that the proposed scheme is more efficient and effective especially when network traffic is heavily loaded.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.92-105
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• 2015

WBAN (Wireless Body Area Network) is a network which is to consistently monitor body signals with implanted or attached sensor nodes. Especially, nodes that are used in medical services have to operate with low power consumption since they are hard to replace, and have to guarantee high data rate and low transmission delay for consistent signal monitor. In this paper, we propose an algorithm that aims to reduce transmission delay and power consumption, and guarantees stable throughput, by assuming the number of active nodes, and followed by dynamically adjusting the random access period and transmission possibilities in a superframe. The assumed number of active nodes may be incorrect since it only relies on the channel status of a previous superframe. Therefore, we assume the number of active nodes and define a pattern. And revise the number of the active nodes with the defined pattern. To evaluate the performance of the proposed algorithm, we have implemented a WBAN environment with the MATLAB. The simulation results show that the proposed algorithm provides better throughput, low power consumption, and low transmission delay when compared to the slotted ALOHA of the IEEE 802.15.6.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.95-101
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• 1985

Fascioliasis in cattle is one of the most common and very serious trematode diseases in Korea. In the present study, the enzyme linked immunosorbent assay (ELISA) was applied in the diagnosis of fascioliasis using antigen of Fasciela hepatica, perokidase of conjugate anti-cattle Is G and orthophenylenediamine as a substrate by micro-method technique of Volley et at. (1976b) and MacLaren (1978) with a slight modification. Results obtained from the present study are as follows. 1. In assay for optimal dilution of stock antigen, the antigen (protein contents; 0. Bmgymz) was diluted from 1150 to 1/600 with carbonate buffer (pH 9.6), and then absorbance values were measured with 1/100 diluted sera. The regression equations between the OD values of ELISA and dilution of antigen were log Y: -0.181-0.00127X in infected sera, and log Y: -0.578-0. 000879X in normal sera. The significantly higher (p<0.05) OD value was observed in the former. 2. In assay for optimal dilution of sera, the sera were diluted from 1125 to 1/400 with in PBSJ Tween 20 (pH 7.4), and absorbance values were measured with 1/200 diluted antigen. The regression equation between the OD values of ELISA and dilution of sera were log Y: -0.1540-0.0007238X in infected sera and log Y: -0.4834-0.00116X in normal sera. The former was higher than the latter (p<0.05). 3. In the 27 cases of negative intradermal test, OD values of the ELISA are $0.447{\pm}0.144$, the 95% confidence interval (Mean+2 H SD) of the values was 0.735, and there was no case over the values. Therefore, the sensitivity of the antigen to diagnose fascioliasis was 100% in the negative case. The OD value 0.7 which is designed as a criterion (detection level of positive one) is useful for the performance of the ELISA in fascioliasis. 4. According to the OD value of criterion in the regression equations, the optimal dilutions of stock antigen and serum were 1/250 and 1/100, respectively. 5. In the 58 cases of fascioliasis from which the adult could be found in the bile ducts, the OD value was $0.846{\pm}0.224$. The 75% (44 cattle) among them had higher value with compared to the criterion, and the 60% (20 cattle) of the cases of proliferative cholangitis of 33 cattle which had been infected previousely with Fasciola sp. is higher than the criterion. 6. Prevalence of fascioliasis was 43.4% in the application of the ELISA to 272 cattle which were reared in Jeonbug district.

• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.6-16
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• 2008

An instable wireless channel condition causes more packet losses and retransmissions due to interference, fading, station mobility, and so on. Therefore video streaming service over a wireless networks is a challenging task because of the changes in the wireless channel conditions and time-constraints characteristics of the video streaming services. To provide efficient video streaming over a wireless networks, QoS-enhanced MAC protocol, IEEE 802.11e, is standardized recently. Tn this paper, we propose a new network-adaptive H.264 video streaming mechanism in the IEEE 802.11e wireless networks. To improve the quality of video streaming services, video stream has to adapt to the changes in the wireless channel conditions. The wireless channel conditions are estimated by the packet loss probability and informed to the application layer by the cross-layering. According to the wireless channel information, the video streaming application filters out the low-priority data. This adaptation mechanism efficiently uses system resources because it drops the low-priority data in advance. Therefore, our cross-layer design can provide improved video streaming services to the end-user. Through the implementation and performance evaluation, we prove that the proposed mechanism improves the QoS of the video streaming by providing the smoothed playback.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.185-191
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• 2015

This paper suggest the safety class communication board in order to design the safety network of the nuclear safety class controller. The reactor protection system use the digitized networks because from analog system to digital system. The communication board shall be provided to pass the required performance and test of the safety class in the digital network used in the nuclear safety class. Communication protocol is composed of physical layer(PHY), data link layer(MAC: Medium Access Control), the application layer in the OSI 7 layer only. The data link layer data package for the cyber security has changed. CRC32 were used for data quality and the using one way communication, not requests and not responses for receiving data, does not affect the nuclear safety system. It has been designed in accordance with requirements, design, verification and procedure for the approving the nuclear safety class. For hardware verification such as electromagnetic test, aging test, inspection, burn-in test, seismic test and environmental test in was performed. FPGA firmware to verify compliance with the life-cycle of IEEE 1074 was performed by the component testing and integration testing.

• Journal of Digital Convergence
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• v.19 no.1
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• pp.475-483
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• 2021

The purpose of this study is to identify the temporal and spatial characteristics of pass accuracy by utilizing the second processing data and official records collected from the 2018 FIFA World Cup Russia video data. For a total of 128 games, the success rate of passes based on the results of the game, passing time, and passing position was two-way ANOVA with repeated measure. The results showed no difference between winning and losing groups, and no interaction effects were found for passing time and location. The difference in passing time was high in the first half, with the highest success rate in the middle of the first half (79.2%) and the middle of the second half (77.9%) in the 15~30 minutes and the 60~75 minutes. Pass success rates were in the order of defense-midfield area (83.9%), midfield-attack area (81.7%), defense area (70.6%) and attack area (61.1%). In conclusion, there was no difference in the passing success rate of the winning and losing teams depending on the characteristics of the relative competitive strength of the World Cup games, and it is believed that follow-up research is needed to analyze the game contents rather than the factors of the winning and losing in the future.