• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.889-897
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• 2002

In this paper, we propose an improved block coding scheme for PAPR reduction in the OFDM communication system. Unlike the conventional block coding scheme which uses one block encoder of subcarrier N, two block encoders of subcarrier N/2 is used for the proposed block coding scheme. This not only improves the coding gain, but enhances the spectral efficiency by twice due to the increment of code rate. PAPR Reduction performance is the same as the conventional block coding. When BER is $10^{-4}$, the proposed block coding scheme has coding gain of 0.5 dB than the conventional scheme.

• Journal of the Korean Institute of Educational Facilities
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• v.8 no.1
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• pp.5-14
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• 2001

The purpose of this study is to clarify the block type of school buildings based on present conditions, by picking up elementary school buildings of Chungbuk Province in Korea. The summary of the block types can be given below. 1) Elementary school buildings(495) in Chungbuk Province are almost built in an average block of 1.7school(290). 2) The block types of school buildings are classified with "-", "ㄱ", "ㄷ", and parallel type. There are many "-" types over and parallel types in the second place of them. 3) The "-" block types are uniformly distributed with 166 elementary schools, below 6 classroom, 7through 24classrooms, beyond 25 classrooms. The "ㄱ" block types are 8 schools, and built as the wing of "-" block type in a limited space. The parallel types are classified with 2 3 lines according to the numbers of paralleled school buildings. The 2 parallel types are firstly represented with more than 95 classrooms, and 5 schools of "ㄷ" types, built as the wing of 2 parallel types, are only represented over 25 classrooms. The 3 parallel types are only 16 schools of all. They are uniformly seen in old and new school buildings.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.1-9
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• 2014

PURPOSES : This study aims to evaluate the performance of interlocking block pavement system for low speed highway. METHODS : Through on-site monitoring, environmental impact assessment of interlocking block pavement such as heat island reduction, traffic safety, noise pollution were evaluated as compared with asphalt pavement. Also the pavement condition and roughness were evaluated according to performance period. RESULTS : Surface temperature of interlocking block pavement was about 7 degree lower than asphalt pavement in midsummer. Compared to asphalt pavement, vehicle speed reduction effect of interlocking block pavement was about 2kph. For low speed driving, the noise pollution was measured at a similar level for both asphalt and interlocking block pavement. After 42month service period, the breakage of block was only 0.24% for the whole surveyed area. IRI of interlock block pavement was estimated within the range of 5~8m/km. CONCLUSIONS : Depending on the performance monitoring results such as heat island reduction, providing traffic safety and keeping a good pavement condition for a long service period, it assures that interlocking block pavement was applicable for low speed road.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.7
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• pp.553-564
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• 1990

The co-efficient matrix of linear second-order partial differential equations in the general form is partitioned with (n-1)x(n-1) submartices and is transformed into the block tridiagonal system. Then the cyclic odd-even reduction technique is applied to this system with the large-grain data granularity and the block cyclic reduction algorithm to solve unknown vectors of this system is created. But this block cyclic reduction technique is not suitable for the parallel processing system because of its parallelism chanigng at every computing stages. So a new algorithm for solving linear second-order partical differential equations is presentes by the block cyclic reduction technique which is modified in order to keep its parallelism constant, and to reduce gteatly its execution time. Both of these algoriths are compared and studied.

• 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.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.1 s.149
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• pp.157-166
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• 2006

The human body, which is composed of concave and convex curvatures, makes it difficult to transfer into 2D patterns directly from 3D data. In previous studies. Jeong, et al.(2004) suggested the block method was fester and easier when dealing with the triangular patches of male's upper dress form. Although the block method is useful to make a pattern, the information(area, length, etc.) from a 2D pattern would be different depending on the direction of the block method. As a result horizontal and diagonal block methods were suggested as optimal methods for 2D tight-fitting patterns. These block methods were closer to the original area of the 3D scan data than the vertical block method. The total area of the 2D pattern obtained by the horizontal and diagonal block methods showed little differences. In case of the horizontal and diagonal block methods, the total error of the 2D pattern area ranged from $0.01\%\~0.25\%$. In comparing the length of the 2D pattern with that of the 3D scan data, the obtained 2D pattern was $0.1\~0.2cm$ shorter than the 3D scan data, which was within the acceptable range of errors in making clothes. 3D space distribution images between the body surface and the experimental clothing were also measured and $3\%$ enlargement of the original pattern was verified as the adequate adjustment.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.3
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• pp.179-184
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• 2022

In this paper, we are going to study how we can automatically determine the number of convolutional filters for the optimal model without a search algorithm. This paper proposes HSE Block by connecting SE Block proposed in SENet to a convolutional neural network and connecting a convolutional neural network not learned at the bottom. An experiment was conducted to increase the number of filters by one per 3 epoch using two datasets for the HSEBlock model and to increase the number of filters by the value in the filter. Based on this experiment, the model was constructed with multi-layer HSE Block instead of layer HSE Block, and the experiment was carried out using a dataset that was more difficult to learn than the one used in the previous experiment. The effect of HSE Block was verified by conducting an experiment with the number of HSE Blocks set to 2, 3, 4, and 5 on a dataset that is more difficult to learn than before.

• Journal of the Korean Ceramic Society
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• v.31 no.1
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• pp.62-68
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• 1994

It is compared the structures of the S-block in the Ba-Co-Zn Y-type hexagonal ferrites (Ba2Co2-xZnxFe12O22, x=0~2) and the Co-Zn spinel ferrites (Co1-xZnxFe2O4, x=0~1) expressed by a hexagonal axis system (space group R3m). The structures have been refined with a Rietveld analysis of the powder X-ray diffraction pattern with high precision (Rwp<0.13, RI<0.03). The overal dimension of the S-block is slightly different from the 1/3 of a hexagonal spinel unit cell as follow: 1.6~2.0% longer c-axis, 1.3~1.6% shorter a-axis and about 1% smaller volume. Upto Zn:Co=1:1 in the Ba-Co-Zn Y-type hexagonal ferrites, the zinc substitute primarily the tetrahedral sites in the S-block. Beyond that the zinc seems to go into the T-block as well.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.167-169
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• 2005

The occurrence of a single bit error in transmission bitstream leads to serious temporal and spatial errors. Because moving picture coding as MPEG-2 based on block coding algorithm uses variable length coding and motion compensation coding algorithm. In this paper, we propose algorithm to conceal occurred error of I-frames in transmission channel using data of the neighboring blocks in decoder. We divide a damaged macroblock of I-frame into four sub blocks and compose new macroblock using the neighboring blocks for each sub block. We estimate the block with minimum difference value through block matching with previous frame for new macroblocks and replace each estimated block with damaged sub block in the same position. Through simulation results, the proposed algorithm will be applied to a characteristic of moving with effect and shows better performance than conventional error concealment algorithms from visual and PSNR of view.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.33.2-33.2
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• 2009

Block copolymer lithography has attracted great attention for emerging nanolithography since nanoscaleperiodic patterns can be easily obtained through self-assembly process without conventional top-down patterning process. Since the morphologies of self-assembled block copolymer patterns are strongly dependent on surface energy of a substrate, suitable surface modification is required. Until now, the surface modification has been studied by using random copolymer or self-assembled mono layers (SAMs). However, the research on surface modifications has been limited within several substrates such as Si-based materials. In present study, we investigated the formation of block copolymer on Au substrate by $O_2$ plasma treatment with the SAM of 3-(p-methoxy-phenyl)propyltrichloro-silane [MPTS, $CH_3OPh(CH_2)_3SiCl_3$]. After $O_2$ plasma treatment, the chemical bonding states of the surface were analyzed by X-ray photoelectron spectroscopy (XPS). The static contact angle measurement was performed to study the effects of $O_2$ plasma treatment on the formation of MPTS monolayer. The block copolymer nanotemplates formed on Au surface were analyzed by scanning electron microscopy. The results showed that the ordering of self-assembled block copolymer pattern and the formation of cylindrical nano hole arrays were enhanced dramatically by oxygen plasma treatment. Thus, the oxidation of gold surface by $O_2$ plasma treatment enables the MPTS to form the monolayer assembly leading to surface neutralization of gold substrates.