• Geomechanics and Engineering
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• v.13 no.3
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• pp.505-515
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• 2017

Based on the collapse characteristics of a shallow rectangular cavity, a three-dimensional failure mechanism which can be used to study the collapsing region of the rock mass above a shallow cavity roof is constructed. Considering the effects of surcharge pressure and surface bolt on the collapsing block, the external rate of works produced by surcharge pressure and surface bolt are included in the energy dissipation calculation. Using variational approach, an analytic expression of surface equation for the collapsing block, which can be used to study the collapsing region of the rock mass above a shallow cavity roof, is derived in the framework of upper bound theorem. Based on the analytic expression of surface equation, the shape of the collapsing block for shallow cavity is drawn. Moreover, the changing law of the collapsing region for different parameters indicates that the collapsing region of rock mass decreases with the increase of the density of surface bolt. This conclusion can provide reference for practicing geotechnical engineers to achieve an optimal design of supporting structure for a shallow cavity.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1365-1381
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• 2023

In this paper, a procedure for evaluating the structural integrity of the PCSG (Printed Circuit Steam Generator) unit block is presented with a simplified FE (finite element) analysis technique by applying the homogenization method. The homogenization method converts an inhomogeneous elastic body into a homogeneous elastic body with same mechanical behaviour. This method is effective when the inhomogeneous elastic body has repetitive microstructures, and thus the method was applied to the sheet assembly among the PCSG unit block components. From the method, the homogenized equivalent elastic constants of the sheet assembly were derived. The validity of the determined material properties was verified by comparing the mechanical behaviour with the reference model. Thermo-mechanical analysis was then performed to evaluate the structural integrity of the PCSG unit block, and it was found that the contact region between the steam header and the sheet assembly is a critical point where large bending stress occurs due to the temperature difference.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.107-115
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• 2014

The reduced-bit transform based bit-plane matching algorithm (BPM) can obtain the block matching result through its simple calculation and hardware design compared to the conventional block matching algorithms (BMAs), but the block matching accuracy of BPMs is somewhat low. In this paper, reduced-bit transform based sum of the absolute difference (R-SAD) is proposed to improve the block matching accuracy in comparison with the conventional BPMs and it is shown that the matching process can be obtained using the logical operations. Firstly, this method transforms the current and the reference images into their respective 2-bit images and then a truth table is obtained from the relation between input and output 2-bit images. Next, a truth table is simplified by Karnaugh map and the absolute difference is calculated by using simple logical operations. Finally, the simulation results show that the proposed R-SAD can obtain higher accuracy in block matching results compared to the conventional BPMs through the PSNR analysis in the motion compensation experiments.

• Economic and Environmental Geology
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• v.18 no.1
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• pp.23-39
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• 1985

The northeastern part of Ogcheon zone which consisted mainly of Cambro-Ordovician arenaceous, argillaceous and calcareous formations and Carboni-Triassic arenaceous and argillaceous formations is delineated as the eastern mass of a thrust fault along Choongju-Moongyong-Cheongsan in the middle of the zone. The present study proposes a geotectonic line, Imgye-Samchog fault(see, figure 1) which divides the northeastern part into two blocks, Hambacksan block in the west and East coast block in the east. The igneous rocks in the Hambacksan block ranging from granite to gabbro are distributed in a symmetrical zones parallel to general direction of Ogcheon zone as follows (Fig. 2 and Table 2). Southeast igneous rock zone: it aligns Jurassic granites in its south and Precambrian leucocratic granites in its north. Central igneous rock zone: it aligns Cretaceous granites in its south and Jurassic granites, and some of diorite and gabbro in its north. Northwest igneous rock zone: aligns Jurassic granites in its south and huge batholithic granodiorite in its north. The distribution of the igneous rocks in the East coast block shows an entirely different features from those of Hanbacksan block. In the southern part of the block they assemble in a narrow area ranging in age from Early Proterozoic, through Middle to Late Proterozoic, Devonian, Jurassic, Cretaceous to Tertiary, whereas, the igneous rocks in the northern part of the block gathered to a restricted area, in ages of Middle Proterozoic and Cretaceous. The assemblage of the igneous rocks in the studied area shows a compositionally restricted, mixed S-type and I-type granites, $^{87}Sr/^{86}Sr$ > 0.706, rare volcanics and shortening with upright folding. These lithologic and structural features suggest that the igneous activity in this part related intimately to Hercynotype Orogeny of Pitcher(1979). Chronological episodes of igneous activity from Early Proterozoic to Early Tertiary in the northeastern part are figured.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.12
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• pp.918-922
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• 2009

Naturally, block mapping FTL works well for sequential writes while page mapping FTL does well for random writes. To exploit their advantages, a practical FTL should be able to selectively apply a suitable scheme between page and block mappings for each write pattern. To meet that requirement, we propose a hybrid mapping FTL, which we call Janus-FTL, that distributes data to either block or page mapping areas. Also, we propose the fusion operation to relocate the data from block mapping area to page mapping area and the defusion operation to relocate the data from page mapping area to block mapping area. And experimental results of Janus-FTL show performance improvement of maximum 50% than other hybrid mapping FTLs.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.956-965
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• 2008

H.264/AVC is the newest video coding standard of ITU-T VCEG and the ISO/IEC MPEG, offering a significant performance improvement over previous video coding standards. However, the computational complexity of H.264/AVC is drastically increased because of new technologies such as intra prediction, variable block size, quarter-pels motion estimation/compensation, etc. In this paper, we propose a fast intra prediction scheme which has two step processing. The first step is a fast block size decision which can be calculated only in one block without considering all cases of $4{\times}4$ block and $16{\times}16$ block. The complexity of the intra prediction can be reduced by using boundary difference values of macroblock. After selecting the block size, we can make mode decision using the neighbouring reference pixels and representative pixels of the block in the second step. The experimental results show that the proposed algorithm saved on the average 41.5% encoding time without any significant PSNR losses.

• Advances in concrete construction
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• v.5 no.5
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• pp.451-468
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• 2017

The problem of reducing the self-weight of reinforced concrete structures is very important issue. There are two approaches which may be used to reduced member weight. The first is tackled through reducing the cross sectional area by using voids and the second through using light weight materials. Reducing the weight of slabs is very important as it constitutes the effective portion of dead loads in the structural building. Eleven slab specimens was casted in this research. The slabs are made one way though using two simple supports. The tested specimens comprised three reference solid slabs and eight styropor block slabs having (23% and 29%) reduction in weight. The voids in slabs were made using styropor at the ineffective concrete zones in resisting the tensile stresses. All slab specimens have the dimensions ($1100{\times}600{\times}120mm$) except one solid specimens has depth 85 mm (to give reduction in weight of 29% which is equal to the styropor block slab reduction). Two loading positions or cases (A and B) (as two-line monotonic loads) with shear span to effective depth ratio of (a/d=3, 2) respectively, were used to trace the structural behavior of styropor block slab. The best results are obtained for styropor block slab strengthened by minimum shear reinforcement with weight reduction of (29%). The increase in the strength capacity was (8.6% and 5.7%) compared to the solid slabs under loading cases A and B respectively. Despite the appearance of cracks in styropor block slab with loads lesser than those in the solid slab, the development and width of cracks in styropor block slab is significantly restricted as a result of presence a mesh of reinforcement in upper concrete portion.

• Journal of Sensor Science and Technology
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• v.22 no.6
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• pp.404-409
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• 2013

We devised calibration procedure for industrial thermometers by a comparison method at the boiling point of nitrogen (${\sim}-196^{\circ}C$). The uncertainty of the calibration was 4 mK (k = 2). As experimentally demonstrated in this work, the effect of the atmospheric pressure on the boiling point of nitrogen can be easily detected by the thermometer. Therefore, when the boiling point of nitrogen is used for calibration of thermometer by comparison, either a reference thermometer must be used to provide the reference temperature or the effect of atmospheric pressure should be carefully considered. The use of a copper block with a large thermal mass soaked into the liquid nitrogen was proven to be more reliable, and the stability of the temperature immersed into the copper block was 1.4 mK. The temperatures at the thermometer wells, evaluated by the crossed-measurement method to compensate for the inaccuracy of the thermometers and the linear drift of the temperature of the copper block, were equivalent within 0.23 mK of standard uncertainty.

• Clinical Pain
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• v.19 no.2
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• pp.90-96
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• 2020

Objective: To investigate the diagnostic accuracy of two physical examinations (straight leg raise [SLR] and Bragard test) and electromyography (EMG) in patients with lumbosacral monoradiculopathy in acute and chronic state on confirmation of different diagnostic criteria (MRI vs MRI and diagnostic selective nerve root block [DSNRB]). Method: We identified 297 participants retrospectively from the departmental database. MRI evidence of L5 or S1 nerve root compression and a positive result in diagnostic SNRB served as reference standards. They were divided into two groups by the symptom duration: lasting more than 12 weeks in the chronic group and less than 12 weeks in the acute group. The diagnostic value of clinical tests and EMG were compared. Results: The clinical tests (SLR and Bragard test) done in acute stage on detection by MRI and DSNRB had the highest sensitivity (68%) compared to the chronic stage (63%), but sensitivity was low (57%) on confirmation of MRI alone. However, there was no significant difference on sensitivity and specificity of EMG regardless of reference standards and symptom duration. Electromyography was a significant predictor of neuropathic abnormalities on both acute (OR, 6.3; 95% CI, 2.4 to 16.7; p<0.01) and chronic (OR, 6.8; 95% CI, 2.9 to 16.3; p<0.01). Conclusion: In general, individual physical tests are easy to do and a combination of those tests could be a sensitive indicator of L5 or S1 radiculopathy. Furthermore, the use of provocation tests could provide useful information, especially in proceeding therapeutic selective nerve root block.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.3
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• pp.391-399
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• 2023

In this paper, we presents for the first time an implementation using T-table for PIPO-64/128, 256 which are lightweight block ciphers. While our proposed implementation requires 16 T-tables, we show that the two types of T-tables are circulant and obtain variants implementations that require a smaller number of T-tables. We then discuss trade-off between the number of required T-tables (code size) and throughput by evaluating the throughput of the variant implementations on an Intel Core i7-9700K processor. The throughput-optimized versions for PIPO-64/128, 256 provide better throughput than TLU(Table-Look-Up) reference implementation by factors of 3.11 and 2.76, respectively, and bit-slice reference implementation by factors of 3.11 and 2.76, respectively.