• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.163-171
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• 2003

Most of existing beam-to-column connections are reinforced symmetrically because of reverse action cause by earthquake but in the weak-earthquake region like Korea connections reinforced asymmetrically can be used. Specially, the connections between CFT(Concrete Filled Tube) column and H-shape beam can be applied by simplified lower diaphragm. The tensile capacity of Combined Cross Diaphragm for upper reinforcing was tested by simple tension test and four types for lower reinforcing; Combined Cross, None, Horizontal T-bar and Vertical Plate were tested by ANSI/AISC SSPEC 2002 loading program. Horizontal T-bar and stud bolts in vertical flat bar transmit tensile stress from bottom flange of beam to filled concrete. All test specimens were satisfied 0.01 radian of inelastic rotational requirement in ordinary moment frame of AISC seismic provision. As the results of parametric studies, simplified lower diaphragms demonstrated an outstanding strength, stiffness and plastic deformation capacity to use sufficient seismic performance in the field.

• Journal of the Korea Concrete Institute
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• v.16 no.6 s.84
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• pp.785-794
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• 2004

This paper describes a new refined truss modeling technique derived based on the well-known relationship of V=dM/dx=zdT/dx+Tdz/dx in a reinforced concrete beam subjected to combined shear and moment loads. The core of the model is that a new perspective on the shear behavior can be gained by considering the variation of the internal arm length along the span, so that the shear resistance mechanism can be expressed by the sum of two base components; arch action and beam action. The sharing ratio of these two actions is determined by accounting for the compatibility of deformation associated to the two actions. Modified Compression Field Theory and the tension-stiffening effect formula in CEB/FIP MC-90 are employed in calculating the deformations. Then the base equation of V=dM/dx has been numerically duplicated to form a new refined truss model.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.487-494
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• 1996

The neurogenic responses of tracheal smooth muscles to electrical field stimulation (EFS) is biphasic, consisting firstly of cholinergic contraction followed by a slow and sustained relaxation. It is well known that a sustained relaxation involves the inhibitory non-adrenergic non-cholinergic systems. This study was done to Investigate the relaxing agents and their action mechanisms by use of an organ bath with plati- ilum . The tracheal smooth muscle relaxation due to EFS was suppressed by L-NAME, the WO (Nitric Oxide) synthase inhibitor, and these effects were reversed by L-arginine, the precursor of NO. Also, L-WAME (HG-nitro-L-arginine methyl ester) increased the basal tension. Nitroprusside, the NO-donor, suppressed the tracheal basal tension greatly. Methylene blue, the inhibitor of guanylate cyclase, decreased EFS-induced relaxations and increa ed basal tension. Forskolin and isoprenaline, which are activators of adenylate cyclase, suppressed tracheal basal tension in the same way as nitroprusside. TEA (tetraethylammonium), the non-specific K'channel blocker, and apamin, the Ca"-activated K'channel blocker, increased tracheal basal tension and EFS-induced relaxations. Our results indicate that Pr3 Is released upon stimulation of the NANC (Won Adrenergic Won Cholinergic) nerves in guinea-pig tracheal smooth muscle and that the release of NO related with the K+ channel, as well as the release of other inhibitory agents< e. g.)VIP (Vasoactive Intestinal Polypeptide), PHI (Peptide Histidine Isoleusine) > mediated via CAMP (cyclic Adenosine Monophosphate) may be Involved In sustained relaxation.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.3
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• pp.197-210
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• 2000

Suppressive role of $Na^+-Ca^{2+}$ exchange in myocardial tension generation was examined in the negative frequency-force relationship (FFR) of electric field stimulated left atria (LA) from postnatal developing rat heart and in the whole-cell clamped adult rat ventricular myocytes with high concentration of intracellular $Ca^{2+}$ buffer (14 mM EGTA). LA twitch amplitudes, which were suppressed by cyclopiazonic acid in a postnatal age-dependent manner, elicited frequency-dependent and postnatal age-dependent enhancements after $Na^+-reduced,\;Ca^{2+}-depleted$ (26 Na-0 Ca) buffer application. These enhancements were blocked by caffeine pretreatment with postnatal age-dependent intensities. In the isolated rat ventricular myocytes, stimulation with the voltage protocol roughly mimicked action potential generated a large inward current which was partially blocked by nifedipine or $Na^+$ current inhibition. 0 Ca application suppressed the inward current by $39{\pm}4%$ while the current was further suppressed after 0 Na-0 Ca application by $53{\pm}3%.$ Caffeine increased this inward current by $44{\pm}3%$ in spite of 14 mM EGTA. Finally, the $Na^+$ current-dependent fraction of the inward current was increased in a stimulation frequency-dependent manner. From these results, it is concluded that the $Ca^{2+}$ exit-mode (forward-mode) $Na^+-Ca^{2+}$ exchange suppresses the LA tension by extruding $Ca^{2+}$ out of the cell right after its release from sarcoplasmic reticulum (SR) in a frequency-dependent manner during contraction, resulting in the negative frequency-force relationship in the rat LA.

• Journal of Korean Association for Spatial Structures
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• v.9 no.3
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• pp.67-74
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• 2009

Presently means of utilizing sensors such as Piezoelectric(PZT) Element for evaluating the affect of oscillator, strain gauge for analyzing physical changes and use of Fiber Bragg Grating(FBG) Sensor are widely practiced in the field. In this study, PZT and FBG sensors were used to tearing damage of cable systems in these sensors. Cable systems are a construction of elements carrying only tension and no compression or bending in membrane structure. But damage detection of cable systems by using existing safety diagnosis is difficult to detect the characteristic change of overall structural action. If cable snaps are occurred to cable release and tear in tension structures, these are set up a vibration. So, we used piezo-electric materials and result of experiment using this was compared with result of experiment using FBG sensors The purpose of this research is to develop of damage detection method of cable system in tensile stress.

• Steel and Composite Structures
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• v.23 no.4
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• pp.473-481
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• 2017

Steel plate shear wall (SPSW) system has been increasingly used for lateral loads resisting system since 1980s when the utilization of post-buckling strength of SPSW was realized. The structural response of SPSWs largely depends on the behavior of the surrounded beams. The beams are normally required to behave in the elastic region when the SPSW fully buckled and formed the tension field action. However, most modern design codes do not specify how this requirement can be achieved. This paper presents theoretical investigation and design procedures of manually calculating the plastic flexural capacity of the beams of SPSWs and can be considered as an extension to the previous work by Qu and Bruneau (2011). The reduction in the plastic flexural capacity of beam was considered to account for the presence of shear stress that was altered towards flanges at the boundary region, which can be explained by Saint-Venant's principle. The reduction in beam web was introduced and modified based on the research by Qu and Bruneau (2011), while the shear stress in the web in this research is excluded due to the boundary effect. The plastic flexural capacity of the beams is given by the superposition of the contributions from the flanges and the web. The developed equations are capable of predicting the plastic moment of the beams subjected to combined shear force, axial force, bending moment, and tension fields induced by yielded infill panels. Good agreement was found between the theoretical results and the data from previous research for flexural capacity of beams.

• Structural Engineering and Mechanics
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• v.59 no.6
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• pp.1121-1137
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• 2016

A large number of structure in the world were build with poor seismic details, with or without any lateral load resisting system like concentrically braced frames and steel plate shear walls. These structures can reveal deteriorating hysteretic behaviors with stiffness and strength degradation. Therefore, seismic retrofitting of such structures for drift control has vital importance. In this study a retrofit methodology has been developed, which involves diagonal bracing of steel frames with different cable arrangements. In the experimental and numerical program 5 different lateral load resisting system were tested and results compared with each other. The results indicated that multi-cable arrangements suggested in this study showed stable ductile behavior without any sudden decrease in strength. Due to the usage of more than one diagonal cable, fracture of any cable did not significantly affect the overall strength and deformation capacity of the system. In cable braced systems damages concentrated in the boundary zones of the cables and beams. That is why boundary zone must have enough stiffness and strength to resist tension field action of cables.

• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.251-269
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• 2016

In common structural systems, there are some limitations to provide adequate lateral stiffness, high ductility, and architectural openings simultaneously. Consequently, the concept of T-Resisting Frame (TRF) has been introduced to improve the performance of structures. In this study, Configuration of TRF is a Vertical I-shaped Plate Girder (V.P.G) which is placed in the middle of the span and connected to side columns by two Horizontal Plate Girders (H.P.Gs) at each story level. System performance is improved by utilizing rigid connections in link beams (H.P.Gs). Plastic deformation leads to tension field action in H.P.Gs and causes energy dissipation in TRF; therefore, V.P.G. High plastic deformation in web of TRF's members affects the ductility of system. Moreover, in order to prevent shear buckling in web of TRF's members and improve overall performance of the system, appropriate criteria for placement of web stiffeners are presented in this study. In addition, an experimental study is conducted by applying cyclic loading and using finite element models. As a result, hysteresis curves indicate adequate lateral stiffness, stable hysteretic behavior, and high ductility factor of 6.73.

• Earthquakes and Structures
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• v.13 no.5
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• pp.473-484
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• 2017

The objective of this paper is to report on a study of the use of unstiffened thin steel plate shear walls (SPSWs) for the seismic performance improvement of reinforced concrete frames with deficient lateral rigidity. The behaviour of reinforced concrete frames during seismic activities was rehabilitated with an alternative and occupant-friendly retrofitting scheme. The study involved tests of eight 1/3 scale, one bay, two storey test specimens under cyclic quasi-static lateral loadings. The first specimen, tested in previous test program, was a reference specimen, and in seven other specimens, steel infill plates were used to replace the conventional infill brick or the concrete panels. The identification of the load-deformation characteristics, the determination of the level of improvement in the overall strength, and the elastic post-buckling stiffness were the main issues investigated during the quasi-static test program. With the introduction of the SPSWs, it was observed that the strength, stiffness and energy absorption capacities were significantly improved. It was also observed that the experimental hysteresis curves were stable, and the composite systems showed excellent energy dissipation capacities due to the formation of a diagonal tension field action along with a diagonal compression buckling of the infill plates.

• Journal of the Korean Society of Costume
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• v.53 no.5
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• pp.65-77
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• 2003

Due to the rapid changes occurring in many aspects of contemporary society, the need for a means to actively combat widespread feelings of emptiness and alienation among the public, while satisfying its visual pleasure, is increasing. Thus the need for humorous elements which bring freedom to the human psyche is urgently requested. Of course, the field of fashion cannot be left out in this trend, and humor image design is a good example of this. Humor image in fashion endeavors to release the tension accumulated in the modern world, while trying to find a way to recover the original pureness of mankind. Another aspect currently important is computers. The creation of images in modern visual art relies a lot upon computers. Traditional visual processes such as painting, photography and video are now merged within digital technology. and are now quite symbiotic to each other. With the development of computers came computer art. which uses all applicable functions of a computer to create art. Any artistic action which uses a computer in any stage of its creation can be called computer art. The common factor in humor and computer art in modern fashion can be classified as follows : repetition, deformation and distortion. exaggeration and abridgement. juxtaposition. and Tromp l'oeil. This study has placed its objective on the fusion of humor image fashion and computer art, by manufacturing a work with humor and computers, two important aspects of modern culture. Expanding the field of fashion design while promoting creativity In fashion by finding a verging point between art and science is also necessary. I have designed and made five costumes using the above cited techniques in computer humor images, on a theoretical basis.