• Journal of Korea Multimedia Society
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• v.15 no.5
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• pp.587-594
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• 2012

IEEE 802.15.6 standard technology is proposed for low-power wireless communication in, on and around body, where vital signs such as pulse, blood pressure, ECG, and EEG signals are transmitted as a type of data packet. Especially, these vital signs should be delivered in real time, so that the latency from slave node to hub node can be one of the pivotal performance requirements. However, in the case of IEEE 802.15.6 technology data retransmission caused by transmission failure can be done in the next superframe. In order to overcome this limitation, we propose an adaptive polling algorithm for IEEE 802.15.6 technology. The proposing algorithm makes the hub to look for an appropriate time period in order to make data retransmission within the superframe. Through the performance evaluation, the proposing algorithm achieves a 61% and a 73% latency reduction compared to those of IEEE 802.15.6 technology in the environment of 70% traffic offered load with 10ms and 100ms superframe period. In addition, the proposing algorithm prevents bursty traffic transmission condition caused by mixing retransmission traffic with the traffic reserved for transmission. Through the proposing adaptive polling algorithm, it will be possible to transmit time-sensitive vital signs without severe traffic delay.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.167-181
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• 2020

Analysis of variance (ANOVA) and multiple comparison analysis were performed for shear strengths categorized by breccia content of 5 wt.% (Case-I), 10 wt.%, (Case-II) and 15 wt.% (Case-III) in fault cores. The relationship between breccia contetnt and shear strength was quantitatively classified by calculating the mean and standard deviation of shear strength for each population in each case and then the grouping the breccia contents that had a statistically similar effect on the dispersion of shear strength. As a result, shear strength was clearly classified into group 1 (breccia content of 0-15 wt.%) and group 2 and 3 (breccia coantent of 15-30 wt.% and 30 wt.% or more) in Case-III. Shear strength of the standard line at breccia content of 15 wt.% were determined to be 43.6 kPa, 77.6 kPa, and 118.6 kPa at each normal stress (54 kPa, 108 kPa, and 162 kPa), respectively. In addition, the distribution range of cohesions is 0-43.6 kPa at breccia content of 15 wt.% or less, and 0-70.0 kPa at 15 wt.% or more. Distribution range of friction angles is 0-45.7 ° at breccia content of 15 wt.% or less, and 16.7-57.5 ° at 15 wt.% or more.

• Journal of the Korean Chemical Society
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• v.22 no.6
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• pp.380-385
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• 1978

Adsorption isotherms of o-xylene on Spheron 6, a graphitized carbon black, are obtained at various temperatures using a quartz beam microbalance. BET plots are made to estimate the molecular area of o-xylene from these isotherms. On Spheron 6, the molecular area of o-xylene (m.p $-25^{\circ}C$) remains constant until the temperature is increased up to $-15^{\circ}C$, but increases abruptly between $-15^{\circ}C$ and $-14^{\circ}C$, and then again remains constant thereafter. These results are interpreted as implying that the adsorbed o-xylene molecules are flatly localized on Spheron 6 with compact packing below $-15^{\circ}C$ while they gain a rotational degree of freedom around the benzene ring at the higher temperature.

• Journal of the Korean Ceramic Society
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• v.26 no.1
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• pp.139-145
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• 1989

An eutectic melt in the system(Bi2O3)0.85·(Nb2O5)0.15-6Bi2O3·SiO2 was unidirectionally solidfield at a rate of 0.5mm/h under a thermal gradient of 100℃/cm. Double crucibles and seed crystal plate were used in order to botain the composite crystals which had uniform microstructure throughout the ingot. The obtained composite crystals showed uniform microstructure, in which needle-like δ-(Bi2O3)0.85·(Nb2O5)0.15 crystals were arrayed in parallel in a matrix of γ-6Bi2O3·SiO2 single crystal. It was found that the <110> direction of δ-(Bi2O3)0.85·(Nb2O5)0.15 crystal was essentially parallel to the <111> direction of γ-6Bi2O3·SiO2 crystal in the composite crystals. A transverse thin plate of the composite crystals showed a high resolution optical transmission like an optical fiber array, and sharp chatoyancy was observed in the cabochon shaped composite crystals. Then, this may be useful for applications such as screen of a cathode ray tube or artificial cat's eye gem stones.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1087-1095
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• 2014

A recent major development in computer technology is the advent of the wearable computer system that is based on human-centric interface technology trends and ubiquitous computing environments. Wearable computer systems can use the wireless universal serial bus (WUSB) that refers to USB technology that is merged with WiMedia PHY/MAC technical specifications. In this paper, we focus on an integrated system of the wireless USB over the IEEE 802.15.6 wireless body area networks (WBAN) for wireless wearable computer systems supporting U-health services. And a communication structure that can differentiate QoS of U-health WBAN and WUSB traffic with different priorities is proposed for WUSB over IEEE 802.15.6 hierarchical protocol. In our proposal and performance evaluation, throughputs of U-health WBAN and WUSB traffic are analyzed under single and multiple QoS classes to evaluate the effectiveness of proposed QoS differentiating structure in WUSB over IEEE 802.15.6.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1619-1627
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• 2014

Wearable computer systems can use the wireless universal serial bus (WUSB) that refers to USB technology that is merged with WiMedia PHY/MAC technical specifications. In this paper, we focus on an integrated system of the wireless USB over the IEEE 802.15.6 wireless body area networks (WBAN) for wireless wearable computer systems supporting U-health services. And a communication structure that performs the time-synchronization is proposed for WUSB over IEEE 802.15.6 hierarchical protocol. Proposed time-synchronization mechanisms adopt the WBAN Polling Access and combine it with a time-synchronization middleware using time stamps. In our performance evaluations, time-synchronization performances with only WBAN Polling Access scheme are analyzed first. After that, performances combined with the time-synchronization middleware are analyzed to evaluate the effectiveness of proposed time-synchronization structure in WUSB over IEEE 802.15.6.

• Journal of Veterinary Clinics
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• v.25 no.5
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• pp.359-362
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• 2008

This study examined the efficacy of needle-acupuncture (AP) at Nei Guan (PC06) and Xin Shu (BL15) on canine tachycardia. A total of 18 beagle dogs were divided into three groups: a control (6 heads), PC06 (6 heads) and PC06 (6 heads) group. Tachycardia was induced by an intramuscular injection of glycopyrrolate. No treatment was given to the control group. Needle-AP at PC06 and BL15 were applied simultaneously at the same time as the glycopyrrolate injection for 20 minutes in PC06 and BL15 groups, respectively. The changes in R-R intervals and respiration rates were determined. The changes in the R-R intervals in the PC06 and BL15 groups were significantly higher than the control group. The R-R intervals of the BL15 group were significantly higher than in the PC06 group. The changes in the respiration rates in the PC06 group were similar to those of the control group. However, the respiration rates in the BL15 group were significantly lower than the control and PC06 groups. In conclusion, needle-AP at PC06 and BL15 is effective in assisting in the recovery from induced canine tachycardia. However, needle-AP at BL15 is more effective than that at PC06.

• Transactions of Materials Processing
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• v.15 no.6 s.87
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• pp.407-413
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• 2006

• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.23-31
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• 2000

The objective of this study was to develop an effective separation and quantification method for kerosene and diesel in a mixed petroleum fuel (gasoline, kerosene, and diesel) contaminated environmental samples. This investigation was directed to prove the hypothesis that if the source of petroleum fuels were identical, the peak-area ratios of a reference n-alkane to other n-alkane peaks should be a constant even at the different concentrations. In addition, experimental recovery rates were determined to select the reference peaks of kerosene and diesel for peak area ratio measurements. The experimental results showed that the peak area ratios were constant among the samples having different concentrations when the ratios were calculated from areas of $C_{l3}$, $C_{l4}$, and $C_{15}$ peaks for kerosene and $C_{l6}$ and $C_{l7}$ peak for diesel as reference n-alkane peaks. The recovery rates were evaluated by comparing the relative peak area ratios of each reference peaks after making pairs of the kerosene and diesel reference peaks in the samples contained a known amount of gasoline, kerosene, and diesel. The recovery rates(%) Were 107.0$_{{\pm}20.6}$/86.6/ sub $\pm$15.9/ for kerosene- $C_{13}$/diesel- $C_{16}$, 99.6$\pm$$_{17.2}$/86.6$_{{\pm}15.9}$ for kerosene- $C_{14}$/diesel- $C_{16}$, 73.9/$\pm$14.4//86.6$_{{\pm}sub 15.9}$ for kerosene- $C_{15}$ /diesel- $C_{16}$, 109.4$_{{pm}0.8}$/75.9$_{{pm}4.7}$ for kerosene- $C_{13}$/diesel- $C_{17}$, 107.4$_{{pm}7.9}$/75.9$_{{pm}4.7}$ for kerosene- $C_{14}$/diesel- $C_{17}$, and 95.7$_{{pm}4.6}$ /75.9/$\pm$14.6//75.9$_{{pm$}4.7}$ for kerosene- $C_{15}$ /diesel- $C_{17.}$ The above experimental results confirm that all of the reference peak pairs of kerosene and diesel are applicable to the quantitative analysis for the mixed fuel contaminated samples, but the kerosene- $C_{15}$ /diesel- $C_{l7}$ peaks are recommended since the pair has a lower standard deviation than the other pairs.s..s.s.s..s..s.s.s.s.s.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.838-839
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• 2016

IEEE 802.15.4 is the standard wireless link technology for low power, low cost, but long lifetime applications including wireless sensor network (WSN). Currently, whether or not IP architecture should be used in WSN over its 802.15.4 link is under dispute. Such kind of arguments may last for a long time without some convincing experimental measurements of real case performances of IP over 802.15.4 implementation, and thus prevent the advance of related research. In RFC4944, IETF proposed the 6LoWPAN specification to enable IPv6 communication over low power, wireless personal area networks. We try to alleviate the dispute and make the direction clearer to the community so as to promote further valuable research in this topic.