• Wind and Structures
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• v.32 no.3
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• pp.227-238
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• 2021

This study analyzed the pressure patterns and local pressure of tall buildings with corner modifications (recessed and chamfered corner) using wind tunnel tests and proper orthogonal decomposition (POD). POD can distinguish pressure patterns by POD mode and more dominant pressure patterns can be found according to the order of POD modes. Results show that both recessed and chamfered corners effectively reduced wind-induced responses. Additionally, unique effects were observed depending on the ratio of corner modification. Tall building models with recessed corners showed fluctuations in the approaching wind flow in the first POD mode and vortex shedding effects in the second POD mode. With large corner modification, energy distribution became small in the first POD mode, which shows that the effect of the first POD mode reduced. Among building models with chamfered corners, vortex shedding effects appeared in the first POD mode, except for the model with the highest ratio of corner modifications. The POD confirmed that both recessed and chamfered corners play a role in reducing vortex shedding effects, and the normalized power spectral density peak value of modes showing vortex shedding was smaller than that of the building model with a square section. Vortex shedding effects were observed on the front corner surfaces resulting from corner modification, as with the side surface. For buildings with recessed corners, the local pressure on corner surfaces was larger than that of side surfaces. Moreover, the average wind pressure was effectively reduced to 88.42% and 92.40% in RE1 on the windward surface and CH1 on the side surface, respectively.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.35-36
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• 2003

The purpose of this work is to investigate the surface modification of LDPE film via corona discharge treatment and subsequent graft polymerization, and their effect on the resulting dyeability is studied in terms of the surface functional groups, surface energetics, and acid-base interaction between the modified LDPE and the dyes used.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.1-19
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• 2002

The use of herbals has increased considerably while their efficacy and safety remain untested. This unsupported surge in demand has prompted a call for their clinical evaluation. One area in which evaluations are emerging is ginseng and diabetes. Growing evidence is accumulating from in vitro and animal models indicating that various ginseng species, American (Panax quinquefolius L), Asian (Panax ginseng C.A. Meyer), Korean Red, San-chi (Panax notoginseng [Burk.] P.R. Chen), and the non-panax species Siberian (Eleutherococcus senticossus) ginsing, and their fractions, saponins (ginsenosides) and peptidoglycans (panaxans for panax species and eleutehrans for Siberian ginseng), might affect carbohydrate metabolism and related signaling molecules. Recent human studies from our laboratory have also shown a blood glucose lowering effect of American ginseng (AG) and some other ginseng spices postprandially after acute administration and chronically after administration for 8-weeks in people with type 2 diabetes. Although generally encouraging, these data only indicate a need for more evaluations of ginsengs safety and efficacy. Because of poor industry standardization, it is not known whether all ginsengs will affect blood glucose. In this regards some ginseng batches have demonstrated null effects while others have even raised postprandial glycemia. Clinical research should therefore focus on components involved in its glucose lowering effects.

• Korean Journal of School Psychology
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• v.16 no.2
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• pp.207-230
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• 2019

This study examined the effect of Attention Feedback Awareness and Control Training(A-FACT) on attention bias and generalized anxiety symptoms in college students. A total of 31 college students with at least 10 points on the Generalized Anxiety Disorder 7-item (GAD-7) scale or at least 56 points on the Korean version of the Penn State Worry Questionnaire (K-PSWQ) with attention bias were randomly assigned to one of three groups: A-FACT( n = 11), Attention Bias Modification (ABM)(n = 10) and Active Placebo Control (APC)(n = 10). Participants in A-FACT group received real-time feedback on attention bias based on their Baseline Neutral Response time(BNR) during A-FACT using a dot probe task. Participants in the ABM group received standard ABM, and those in the APC performed a dot probe task that they were informed was a program to reduce attention bias, but feedback was not provided. A total of eight sessions was conducted twice a week over a 4-week period. After every two sessions, GAD-7, K-PSWQ and K-STAI were rated. The effect of attention bias modification training was rated by changes in the Attention Bias Score(ABS), and in GAD-7, K-PSWQ and K-STAI scores. The results of repeated measure ANOVA indicated that the A-FACT group showed a significant decrease in ABS as well as in GAD-7, K-PSWQ and K-STAI scores compared to the other groups. Current results suggest that self-regulatory control of attention, that is, recognition of bias through feedback in A-FACT, may be effective in alleviating attention bias and generalized anxiety symptoms by recognizing bias through feedback on bias in attention bias modification training.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1367-1370
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• 1997

This paper presents a vision algorithm for finding the centers of steam generator tubes using the generalized symmetry transform, which is used for ECT(Eddy Current Test) of steam generator tubes in nuclear power plants. The geometrical properties of the image representing steam generator tubes shows that they have amost circular or somewhat elliptic appearances and each tube has strong symmetry about its center. So we apply the generalized symmetry transform to finding centers of steam geneator tubes. But applying the generalized symmetry transform itself without any modification gives difficulties in obtaining the exact centers of steam generator tubes. But applying the generalized symmetry transform itself without any modification gives difficulties in obtaining the exact centers of tubes due to the shadow effect generated by the local light installed inside steam generator. Therefore we make the generalized symmetry transform modified, which uses a modified phase weight function in getting the symmetry magnitude in order to overcome the misleading effect by the local light. The experimental results indicate that the proposed vision algorithm efficiently recongnizes centers of steam generator tubes.

• Textile Coloration and Finishing
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• v.19 no.1 s.92
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• pp.45-52
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• 2007

Polyacrylonitrile(PAN) fiber was treated with low-temperature plasmas of argon and oxygen for surface modification, and its surface chemical structure and morphology were examined by a field emission scanning electron microscope(FESEM) and a Fourier-transform infrared microspectroscopy(IMS). The argon-plasma treatment caused the only mechanical effect by sputtering of ion bombardment, whereas the oxygen plasma brought about a chemical effect on the PAN fiber surface. The experimental evidences strongly suggested that cyclization of nitrile group and crosslinking were likely to occur in the oxygen-plasma treatment. On the other hand, with the argon-plasma treatment, numerous my pits resulted in ranging from several tens to hundreds nanometers in radius. The plasma sensitivity of functional groups such as C-H, $C{\equiv}N$, and O-C=O groups in the PAN fiber was dependent on their chemical nature of bonding in the oxygen-plasma, in which the ester group was the most sensitive to the plasma. Vacuum-ultraviolet(VUV) radiation emitted during plasma treatment played no substantial role to alter the surface morphology.

• IMMUNE NETWORK
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• v.5 no.4
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• pp.199-204
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• 2005

Background: ADP-ribosyl pyrophosphatases (ADPRase) has been known to catalyze the hydrolysis of ADP-ribose to ribose-5-phosphate and AMP. The role of ADPRase has been suggested to sanitize the cell by removing potentially toxic ADP-ribose. In this study, we examined the effect of nitric oxide on ADPRase activity in macrophages. Methods: ADPRase activity was measured in NO-inducing J774 cells. For in vitro experiments, recombinant human ADPRase was prepared in bacteria. Results: ADPRase activity was increased by the treatment of exogenous NO generating reagent, sodium nitroprusside (SNP), in J774 cells. The increased ADPRase activity was mediated by the post-translational modification, likely to cause cADP-ribosylation via nitrosylation of cysteine residue on the enzyme. The stimulation with endogeneous NO inducers, $TNF-{\alpha}/IFN-{\gamma}$, also increased ADPRase activity through NO synthesis. Futhermore, ADPRase activity may be mediated by the post-translational modification of ADPRase, ADP-ribosylation. Conclusion: These results indicate that NO synthesized by macrophage activation plays a critical role in the increase in ADPRase activity following ADP-ribose metabolism.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.25-32
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• 1998

Most recent seismic design codes include Response Modification Factor(RMF) for determining equivalent lateral forces. The RMF is used to reduce the linear elastic design spectrum to account for the energy dissipation capacity, overstrength and damping of the structure. In this study the RMF is defined as the ratio of the absolute maximum linear elastic base shear to the absolute maximum nonlinear base shear of a structure subject to the same earthquake accelerogram. This study investigates the effect of hysteretic model, as well as target ductility ratio and natural period on duct based RMF using nonlinear dynamic analyses of the SDOF systems. Special emphasis is given to the effects of the hysteretic characteristics such as strength deterioration and stiffness degradation. Results indicate that RMFs are dependent on ductility, period and hysteretic model.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.615-622
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• 2002

In this paper, the modification of double projection method for the adaptive analysis of Element-free Galerkin(EFG) method were proposed. As results of the double projection method, the smoothed error profile that is adequate for adaptive analysis was obtained by re-projection of error that means the differences of EFG stress and projected stress. However, it was found that the efficiency of double projection method is degraded as increase of the numerical integration order. Since, the iterative refinement to single step error estimation made the same effect as increasing of integration order, the application of the iterative refinement base on double projection method could be produced the inadequately refined analysis model. To overcome this defect, a modified scheme of double projection were proposed. In the numerical example, the results did not show degradation of double projection effect in iterative refinement and the efficiency of proposed scheme were proved.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2554-2557
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• 2008

Effect of a particle's spin is investigated numerically by considering the effect of lift occurring due to difference of rotations of a particle and of fluid such as the Saffman lift and Magnus force. These lift forces have been neglected in many previous works on particle-laden turbulence. The trajectory of particles can be changed by the lift forces, resulting in significant modification of the stochastic characteristics of heavy particles. Probability density functions and autocorrelations are examined of velocity, acceleration of solid particle and acceleration of fluid at the position of solid particle. Changes in velocity statistics are negligible but statistics related with acceleration are a little bit changed by particle's rotation. When a laden particle encounters with coherent structures during the motion, the particle's rotation might significantly affects the motion due to intermittently large fluid acceleration near coherent structures.