• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2237-2246
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• 2010

In this paper, the performance of a RCO-MAC protocol is evaluated using a different traffic model. Data frames are assumed to generate based on an exponential distribution from one source node and then directly to be stored into the input buffer in the source node. System throughput, average access delay and average system delay are used as a performance measure. Performance evaluation is carried out by the computer simulation. Numerical results show that the RCO-MAC scheme offers 18% higher system throughput than the rDCF scheme. In addition, the numerical results show that the RCO-MAC protocol also offers the better average system delay under any traffic load than that by the rDCF scheme, which was not obtained in the previous research due to the saturated traffic model.

• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.497-506
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• 2020

CA mortar layer disengagement will give rise to the overall structural changes of the track and variation in the vibration form of the ballastless track. By establishing a vehicle-track-viaduct coupling analysis and calculation model, it is possible to analyze the CRTS-I type track structure vibration response while the track slab is disengaging with the power flow evaluation method, to compare the two disengaging types, namely partial contact loss at one edge beneath track slab and partial contact loss at midpoint beneath track slab. It can also study how the length of disengaging influences the track structures vibration power. It is showed that when the partial contact loss beneath track slab, and the relative vibration energy level between the rail and the track slab increases significantly within [10, 200]Hz with the same disengaging length, the partial contact loss at one edge beneath track slab has more prominent influence on the vibration power than the partial contact loss at midpoint beneath track slab. With the increase of disengaging length, the relative vibration energy level of the track slab grows sharply, but it will change significantly when it reaches 1.56 m. Little effect will be caused by the relative vibration energy level of the viaduct. The partial contact loss beneath the track slab will cause more power distribution and transmission between the trail and track slab, and will then affect the service life of the rail and track slab.

• Resources Recycling
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• v.10 no.6
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• pp.22-28
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• 2001

A study on the recovery of yttrium was conducted using the phosphor sludges generated in the recycling process of obsolete CRTs. Yttrium was leached by HCl and $HNO _3$. The leaching efficiency of yttrium was extensively investigated in terms of acid concentration, leaching temperature and time, and pulp density. Yttrium and lead was recovered from leaching solutions also by precipitation method. The leaching behavior of yttrium was similar in both acids. The leaching efficiency of yttrium for both acids increased with time at the conditions of 3.0M, $90^{\circ}C$, and 280 g/L of pulp density. After 40 minutes, it was saturated to 93% and 90% for HCl and HNO$_3$respectively. Yttrium was recovered from leaching acid solution by the addition of $H_2$$C_2$$O_4$while lead was removed as $PbSO_4$by $Na_2$ $SO_4$.

• The Transactions of the Korea Information Processing Society
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• v.6 no.7
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• pp.1929-1940
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• 1999

In this paper a VLSI design for the automatic magnetizing and inspection system has been presented. This is a design of a peripheral controller, which magnetizes CRTs and computer monitors and controls the automatic inspection system. We implemented a programmable peripheral interface(PPI) circuit of the control and protocol module for the magnetizer controller by using a 0.8um CMOS SOG technology of ETRI. Most of the PPI functions have been confirmed. In the conventional method, the propagation/ramp delay model was used to predict the delay of cells, but used to model on only a single cell. Later, a modified "linear delay predict model" was suggested in the LODECAP(LOgic DEsign CAPture) by adding some factors to the prior model. But this has not a full model on the delay chain. In this paper a new " delay predict equation" for the design of the timing control block in PPI system has been suggested. We have described the detail method on a design of delay chain block according to the extracted equation and applied this method to the timing control block design. And we had descriptions on the other blocks of this system.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6115-6120
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• 2014

Background: To compare the KKU-model rectal tube (KKU-tube) and the conventional rectal tube (CRT) for checking rectal doses during high-dose-rate intracavitary brachytherapy (HDR-ICBT) of cervical cancer. Materials and Methods: Between February 2010 and January 2011, thirty -two patients with cervical cancer were enrolled and treated with external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT). The KKU-tube and CRT were applied intrarectally in the same patients at alternate sessions as references for calculation of rectal doses during ICBT. The gold standard references of rectum anatomical markers which are most proximal to radiation sources were anterior rectal walls (ARW) adjacent to the uterine cervix demonstrated by barium sulfate suspension enema. The calculated rectal doses derived from actual anterior rectal walls, CRT and the anterior surfaces of the KKU-tubes were compared by using the paired t-test. The pain caused by insertion of each type of rectal tube was assessed by the visual analogue scale (VAS). Results: The mean dose of CRT was lower than the mean dose of ARW ($Dmean_0-Dmean_1$) by $80.55{\pm}47.33cGy$ (p-value <0.05). The mean dose of the KKU-tube was lower than the mean dose of ARW ($Dmean_0-Dmean_2$) by $30.82{\pm}24.20cGy$ (p-value <0.05). The mean dose difference [($Dmean_0-Dmean_1$)-($Dmean_0-Dmean_2$)] was $49.72{\pm}51.60cGy$, which was statistically significant between 42.32 cGy -57.13 cGy with the t-value of 13.24 (p-value <0.05). The maximum rectal dose by using CRT was higher than the KKU-tube as much as 75.26 cGy and statistically significant with the t-score of 7.55 (p-value <0.05). The mean doses at the anterior rectal wall while using the CRTs and the KKU-tubes were not significantly different (p-value=0.09). The mean pain score during insertion of the CRT was significantly higher than the KKU-tube by a t-score of 6.15 (p-value <0.05) Conclusions: The KKU-model rectal tube was found to be an easily producible, applicable and reliable instrument as a reference for evaluating the rectal dose during ICBT of cervical cancer without negative effects on the patients.