• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.77-85
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• 2013

The aim of this study is to investigate strength and water purification characteristics of effective microorganism-applied volcanic ash block using flexural strength test and water quality analysis. The specimens were prepared with volcanic ash from Mt. Baekdusan and Mt. Hallasan, and cement as the ratios of 3.5:1, 4.0:1, 4.5:1, 5.0:1 with and without metakaolin. Flexural strength degraded with increasing of the amount of volcanic ash, and increased with addition of metakaolin as a binder. Based on these results, the optimal ratio for fabricating volcanic ash-cement mixture block is determined as 3.5:1 with metakaolin. Furthermore, from water quality analysis on contaminated water, removal ability of effective microorganism-applied volcanic ash-cement mixture block and caged volcanic ash block against T-N, T-P and SS was highly evaluated because of adsorption due to the large specific surface area of volcanic ash. Hence, volcanic ash-cement mixture block and caged volcanic ash block possibly contribute to water purification.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.117-123
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• 2013

By calculating the spectral efficiency of symmetric balance incomplete block design(BIBD) codes satisfying BER=$10^{-9}$, it can be found that ideal BIBD code design with m=2 and various q's is effective when effective power is high($P_{sr}=-10$ dBm). But BIBD code design with q > 2 and various m's can be effective when effective power is low($P_{sr}=-25$ dBm).

• Journal of the Korea Society of Computer and Information
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• v.7 no.4
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• pp.102-107
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• 2002

Compression coding based on block coding has been applied in image and video compression standard. But there is no block effect measurement due to block based image coding. In this paper, we propose a objective block effects measurement to reconstructed image using subblock DCT coding. Experimental results show that the block effects measures given by the suggested method agree well with the subjective ranking. This new objective measurement is simple and effective in measuring the block effect in the reconstructed image.

• Radiation Oncology Journal
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• v.13 no.2
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• pp.199-203
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• 1995

Purpose: To evaluate the dose under lung block as a function of depth and the effectiveness of a block as a function of block width. Materials and Methods : Field size of mantle field was $22.8{\times}32.4cm^2.$ Dose distribution of the mantle field was measured with two dimensional water phantom system. To analyze the effectiveness of the lung block. central axis plane, 5cm off-axis plane, and 10cm off-axis plane were studied. Results: The dose under the lung block was recorded with maximum at the depth between 5cm and 10cm. In the central axis plane, dosimetric block width was $10-15\%$ less than physical block width. In the 5cm off-axis plane, dosimetric block width was $4-9\%$ less than physical block width. In the 10cm off-axis plane, dosimetric block width was $2\%$ less than physical block width. Conclusion: Depth dependence of the dose under the lung block was founded. Also, block width dependence of the lung block was founded. To induce the accurate relation between the physical block width and the 'effective' block width, it needs more detailed understanding of the variables involved.

• The Korean Journal of Pain
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• v.8 no.1
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• pp.139-143
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• 1995

Hyperhidrosis is the state of abnormal sweating on the palm, sole and axillary region. The main treatment of hyperhidrosis are surgical sympathectomy and a thoracic sympathetic ganglion block with neurolytics. Among them, a thoracic sympathetic ganglion block is used in pain clinic for the treatment of hyperhidrosis. I have successfully performed a thoracic sympathetic ganglion block on a 21 year old female patients with pure alcohol. I concluded that the thoracic sympathetic ganglion block was one of the most effective treatment of hyperhidrosis.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.65-74
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• 2014

IEEE 802.11n standard has introduced the new schemes in MAC and PHY layers to improve network throughput. Frame aggregation and Block ACK are mainly defined to increase the efficiency of the MAC layer. There exists still problem in IEEE 802.11n. When block ACK request and/or response frames are missing or received in error, the sender does not know the status (success/failure) of each frame in the aggregated large frame and retransmits all the frames. This can cause a lower network performance. To solve this problem, we propose a new effective scheme, called reduced retransmission of MPDUs (RRM) scheme. In the proposed scheme, when a sender does not receive a block ACK response frame, it just transmits a next data frame and requests a block ACK. Therefore, it can retransmits the erroneous frames. Performance of the proposed scheme is investigated by simulation. Our results show that the proposed scheme is very effective and improves the performance under a wide range of channel error conditions.

• The Korean Journal of Pain
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• v.5 no.1
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• pp.17-22
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• 1992

Splanchnic nerve block(SNP) is performed to relieve intractable upper abdominal cancer pain. Boas, in a technique using fluoroscopy, was the first to note the difference between transcrural celiac plexus block and retrocrural splanchnic nerve block(SNB). We have experienced 10 cases of SNB at the T12 level under control of fluoroscopy. Our results support this approach as an effective method for upper abdominal cancer pain control.

• The Korean Journal of Pain
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• v.30 no.2
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• pp.93-97
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• 2017

The sphenopalatine ganglion (SPG) is a parasympathetic ganglion, located in the pterygopalatine fossa. The SPG block has been used for a long time for treating headaches of varying etiologies. For anesthesiologists, treating postdural puncture headaches (PDPH) has always been challenging. The epidural block patch (EBP) was the only option until researchers explored the role of the SPG block as a relatively simple and effective way to treat PDPH. Also, since the existing evidence proving the efficacy of the SPG block in PDPH is scarce, the block cannot be offered to all patients. EBP can be still considered if an SPG block is not able to alleviate pain due to PDPH.

• The Korean Journal of Pain
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• v.4 no.2
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• pp.111-121
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• 1991

It has been well known that the splanchnic nerve block is effective for patients who suffer from intractable upper abdominal pain. However, it is unclear whether the effect of the splanchnic nerve block depends on varied alcoholic concentration. In this study, an attempt was made to use absolute ethanol on patients who recieved a splanchnic nerve block at Severance Hospital during the period from September l990 to April l991. The results are as follows; 1) Among the 33 patients, including 22 males and 1l females, the fifties and sixties were the major age groups. 2) Stomach cancer was the most common underlying disease(13 cases), with pancreatic can- cer next(9 cases). 3) The main locations of pain were the upper abdomen, epigastrium, and entire abdomen in decreasing order. 4) There were 17 cases who had had chemotherapy, and 1l cases of whom had had surgery before the splanchnic nerve block. 5) The volume of alcohol used was 12 ml bilaterally. 6) Among the 33 patients, 15.2% required a second block within two weeks of the first block. One case required a third block. 7) The most common complications of splanchnic nerve block were hypotension(33.3%), occasional transient sharp burning pain, flushing of face, pain on injection site, nausea, vomiting, dyspnea, chest discomfort and diarrhea. 8) The supplemental block most commonly used was a continuous epidural block. It was used both as a diagnostic block and to afford relief from pain before the splanchnic nerve block was done. 9) The interval between the receiving the absolute ethanol block and discharge was within 2 weeks in l5 cases. But, in the patients with poor general health, the interval between the splanchnic nerve block and discharge prolonged. The above results suggest that bilateral splanchnic nerve block done with absolute ethanol after an effective test block with 1% lidocaine under C-arm fluroscopic control is satisfactory and reliable. Still, 26.6% of the patients received a repeat block within 2 weeks. Insufficient spread of ethanol due to its small volume seems to be a major factor in the repeat block. Minimizing the incidence of repeat block remains a problem to be solved.

• Journal of Magnetics
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• v.19 no.1
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• pp.15-19
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• 2014

In this study, for 6-20 MeV electron beam energy occurring in a linear accelerator, the authors attempted to investigate the relation between the effective source-skin distance and the relation between the radiation field and the effective source-skin distance. The equipment used included a 6-20 MeV electron beam from a linear accelerator, and the distance was measured by a ionization chamber targeting the solid phantom. The measurement method for the effective source-skin distance according to the size of the radiation field changes the source-skin distance (100, 105, 110, 115 cm) for the electron beam energy (6, 9, 12, 16, 20 MeV). The effective source-skin distance was measured using the method proposed by Faiz Khan, measuring the dose according to each radiation field ($6{\times}6$, $10{\times}10$, $15{\times}150$, $20{\times}20cm^2$) at the maximum dose depth (1.3, 2.05, 2.7, 2.45, 1.8 cm, respectively) of each energy. In addition, the effective source-skin distance when cut-out blocks ($6{\times}6$, $10{\times}10$, $15{\times}15cm^2$) were used and the effective source-skin distance when they were not used, was measured and compared. The research results showed that the effective source-skin distance was increased according to the increase of the radiation field at the same amount of energy. In addition, the minimum distance was 60.4 cm when the 6 MeV electron beams were used with $6{\times}6$ cut-out blocks and the maximum distance was 87.2 cm when the 6 MeV electron beams were used with $20{\times}20$ cut-out blocks; thus, the largest difference between both of these was 26.8 cm. When comparing the before and after the using the $6{\times}6$ cut-out block, the difference between both was 8.2 cm in 6 MeV electron beam energy and was 2.1 cm in 20 MeV. Thus, the results showed that the difference was reduced according to an increase in the energy. In addition, in the comparative experiments performed by changing the size of the cut-out block at 6 MeV, the results showed that the source-skin distance was 8.2 cm when the size of the cut-out block was $6{\times}6$, 2.5 cm when the size of the cut-out block was $10{\times}10$, and 21.4 cm when the size of the cut-out block $15{\times}15$. In conclusion, it is recommended that the actual measurement is used for each energy and radiation field in the clinical dose measurement and for the measurement of the effective source-skin distance using cut-out blocks.