• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.1-10
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• 1992

In this study, the 'Comb-structure' model which has been developed from truss analogy is modified in order to be applied to the shear analysis of partially prestressed concrete members. The proposed 'Comb-structure' model is modified so that the position, the slope of concrete compressive chord and the slope of concrete diagonal strut may change according to the magnitude of loads and prestress. For the proposed mechanical model, non-linear beam and truss elements are used. By modifying the 'Compression-Field' theory, the equation to determine the slope angle of concrete diagonal strut can be induced. The anaysis results by the proposed 'Comb-structure' model are compared with the experimental results and validity of model is examined. It shows that the the result of 'Comb-structure' analysis lies between that of the modified M$\ddot{o}$rsch theory and classical M$\ddot{o}$rsch theory, and close to the measured value after cracking. The deflection of the beam and the stress of stirrup show good agreement, so it can be concluded that the proposed 'Comb-structure' analysis model explains the shear behavior of partially prestressed concrte beams after crack initiation.

• Korean Journal of Materials Research
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• v.19 no.8
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• pp.447-451
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• 2009

The long-period stacking order (LPSO) structures and stacking faults (SFs) in rapidly solidified powder metallurgy (RS P/M) $Mg_{97}Zn_1Y_2$ alloy were investigated by high resolution transmission electron microscopy (HRTEM) observations. The 18R-type LPSO structure with a stacking sequence of ACBCBCBACACACBABAB and a period of 4.86 nm was observed in the as-extruded RS P/M $Mg_{97}Zn_1Y_2$ alloy. After annealing at 773 K for 5 hr, the 18R-type LPSO structure was transformed to the 14H-type LPSO structure with a stacking sequence of ABABABACBCBCBC and a period of 3.64 nm. The 24R-type LPSO structure containing 24 atomic layers of ABABABABCACACACABCBCBCBC with period of 6.18 nm coexists with the 14H-type LPSO structure in the same grains. The LPSO structures contain intrinsic Type II SFs such as BCB/CABA and ABA/CBCB stacking sequences of a closely packed plane.

• Journal of Korean Association for Spatial Structures
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• v.18 no.1
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• pp.93-100
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• 2018

The retractable roof structures have actions of various types of loads and external forces depending on the retraction and operation conditions of the roof in terms of efficiency of control and maintenance as the aspect of structural plan. In particular, there is a need for studies on the establishment of retraction controlled wind velocity to maintain the stable control and usability of roof structure against strong winds or sudden gusts during the retraction of the roof. In this paper, it was intended to provide basic materials for the development of guidelines on the operation and maintenance of domestic retractable buildings with large space by analyzing the factors affecting the retraction controlled wind velocity for the overseas stadiums with the large spatial retractable roof structures where the sliding system was applied on the steel retractable systems. As a result, the controlled wind velocity tends to decrease as the retractable roof area increases. On the other hand, the controlled wind velocity tends to increase as the retraction time increases. In addition, in the space-grid roof structures, the spherical roof structures type showed the average controlled wind velocity of 10m/sec lower than that of 17.3m/sec for curved-roof structure type, and in the curved-roof structure type, the truss roof structure showed the average controlled wind velocity of 8.9m/sec which is lower than that of 17.3m/sec for the space for the space-grid roof structure.

• Cross-Cultural Studies
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• v.23
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• pp.7-32
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• 2011

In this article, we tried to introduce a little-known work of M.A. Bulgakov "Snowstorm" and provide some various clues for reading this short story. This study is focused on "snowstorm-plot", grasping the structure and the theme of the present work. To this end, in the Chapter II we tired to seek for the meanings of Bulgakov's "snowstorm" based on intertextuality shown from the works by those writers such as Pushkin, Gogol and Tolstoy. In this short story "snowstorm" is presented not only as a natural phenomenon but as a "participant" which provides young doctor-narrator with short time break and let him go to a dying bride, and at last place him on the crossroads of life and death. Indeed "snowstorm" plays a role of the framed structure of Bulgakov's text. In the Chapter III we observed the creative expression of Bulgakov's work which is comprised of overlappings with dream and reality. In other words, in the short story "Snowstorm" the outside and the inside story of frame are described as a dream of the one same night. We can guess that the Shermetievo story is a kind of dream of young doctor who fell asleep in Tuesday night, asking himself "how many patients will come tomorrow?". By the way the Shermetievo story unfolds as an incident which is happened on Wednesday. In this way in Bulgakov's "Snowstorm" it is hard to draw clear lines of demarcation between dream and reality. Therefore existential themes like these "Life and Death", "Professional calling and personal conscience", "The great nature and the week human being" are resonated with original structure "Dream in Dream".

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.1
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• pp.67-74
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• 1998

This paper performed terrain analysis using DTM(digital terrain model) with TIN/ GRID structure on PC environment. Contour layer from 1:5,000 scale map was used to produce DTM. DTHs were produced with and without considering breakline for each data structure. Processing time, file size, mean elevation and standard variation were analyzed for each DTM. slope map, aspect map were analyzed for grid structure with consideration of TEX>$5\times{5m},\;l0\times{10m},\;15\times{15m},\;l0\times{30m},\;45\times{45m},\;60\times{60m}$ cell size respectively. The results suggest following; The incorporation of breakline does improve mapping accuracy for highly disturbed landscape, Mean elevation doesn't increase as the grid size increases, while processing time, storage room is significantly lessened. Thus, the optimal grid size must be determined in advance for efficient application. slope decreases, while aspect increases as grid size is increasing.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.253-259
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• 2000

This thesis investigated the behavior of super structure by varying the factors such as the change of pile rigidity, the characteristics of soil and the constraint condition of support. The results of this study are as follows; 1. The pile rigidity in the Fig 3.3 computed by the rotating deformed plane method becomes the elastic range at approximately about 5.1 m (D : 1.0 m) below the ground level. This result is consistent with the previous study that the pile deformation occurs approximately 3 to 6 times pile diameter from the pile head. 2. The values of forces and deformations for the structure-pile system in Y-direction appeared larger than that in X-direction, since the pile rigidity and constraint condition of support were changed as shown Fig.3.5 to 3.8. 3. The current practice for the analysis of structure-pile system has not considered the variation of pile rigidity and the constraint condition of support. So, the analysis of structure-pile system with large difference in super-structure rigidity must includes these factors in both X and Y directions.

• Kyungpook Mathematical Journal
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• v.50 no.4
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• pp.455-463
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• 2010

The differentiable manifold with f - structure were studied by many authors, for example: K. Yano [7], Ishihara [8], Das [4] among others but thus far we do not know the geometry of manifolds which are endowed with special polynomial $F_{a(j){\times}(j)$-structure satisfying $$\prod\limits_{j=1}^{k}\;[F^2+a(j)F+\lambda^2(j)I]\;=\;0$$ However, special quadratic structure manifold have been defined and studied by Sinha and Sharma [8]. The purpose of this paper is to study the geometry of differentiable manifolds equipped with such structures and define special polynomial structures for all values of j = 1, 2,$\ldots$,$K\;\in\;N$, and obtain integrability conditions of the distributions $\pi_m^j$ and ${\pi\limits^{\sim}}_m^j$.

• Journal of the Korea Computer Industry Society
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• v.6 no.5
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• pp.783-790
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• 2005

In this paper, we have simulated a Symmetric Dual-gate Single-Si TFT which has three split floating n+ zones. This structure reduces the kink-effect drastically and improves the on-current. Due to the separated floating n+ zones, the transistor channel region is split into four zones with different lengths defined by a floating n+ region, This structure allows an effective reduction of the kink-effect depending on the length of two sub-channels. The on-current of the proposed dual-gate structure is 0.9mA while that of the conventional dual-gate structure is 0.5mA at a 12V drain voltage and a 7V gate voltage. This result shows a 80% enhancement in on-current. Moreover we observed the reduction of electric field in the channel region compared to conventional single-gate TFT and the reduction of the output conductance in the saturation region. In addition, we also confirmed the reduction of hole concentration in the channel region so that the kink-effect reduces effectively.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.60.2-60.2
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• 2014

Hierarchical structure of star-forming regions is widespread and may be characteristic of all star formation. We studied the hierarchical structure of star-forming regions in the Local Group galaxies (M31, M33, Phoenix, Pegasus, Sextans A, Sextans B, WLM). The star-forming regions were selected from Galaxy Evolution Explorer (GALEX) far-UV imaging in various detection thresholds for investigating hierarchical structure. We examined the spatial distribution of the hot massive stars within star-forming regions from Hubble Space Telescope (HST) multi-band photometry. Small compact groups arranged within large complexes. The cumulative mass distribution follows a power law. The results allow us to understand the hierarchical structure of star formation and recent evolution of the Local Group galaxies.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.83.1-83.1
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• 2010

In the last meeting of KAS, we reported the first statistical study of Faraday rotation measure (RM) in the large-scale structure of the universe using the data of cosmological structure formation simulations. With a turbulence dynamo model for the intergalactic magnetic field (IGMF), we predicted that the root mean square of RM through filaments is \sim 1 rad/m^2. Future radio observatories such as the Square Kilometer Array (SKA) could detect this signal level. However, it is known that the typical foreground galactic RM is a few tens and less than ten rad/m^2 in the low and high galactic latitudes, respectively. So the RM in the large-scale structure could be detected only after the foreground galactic RM is removed. In this talk, we show how we remove the foreground galactic RM and what we obtain from the masked data, by using some noise models and masking techniques. Our results can be used to simulate future RM observations by SKA, and eventually to constrain the origin and evolution of the IGMF in the large-scale structure.