• Smart Structures and Systems
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• v.17 no.5
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• pp.819-835
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• 2016

In this paper, the activities carried out within the EU funded Clean Sky Joint Technology Initiative (JTI GRA) Project and aimed at developing a morphing flap, are illustrated. The reference device is a regional aircraft single slotted flap, enhanced with deforming capabilities to obtain improved hyper-lift performance. The design started with the identification of the internal architecture, intended to allow camber variations. A concentrated-hinge architecture was selected, for its ability to fit different curvatures and for the possibility of easily realizing an "armadillo-like" configuration, then avoiding the use of a complicate deformable skin. The flap layout is made of segmented ribs, elastically hinged each other and span-wise connected by conventional spars. Relative rotations of the rib elements are forced by SMA structural actuators, i.e., cooperating in the external loads absorption. Super-elastic SMA are used to make up recovery elastic elements, necessary to regain the original shape after activation. These further elements in turn contribute to the overall flap rigidity. After assessing the hinge number and the size of the SMA active and passive elements, the advanced design phase was dealt with. It was aimed at solving manufacturing issues and producing the executive drawings. The realized demonstrator was finally tested in lab conditions to prove its functionality in terms of whether target shape actuation or attained shape preservation under loads. On the basis of the numerical results and the experimental outcomes, precious hints were obtained for further developments of the concept.

• Wind and Structures
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• v.30 no.5
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• pp.465-474
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• 2020

Vortex-induced vibrations of a yawed flexible cylinder near a plane boundary are numerically investigated at a Reynolds number Re_n= 500 based on normal component of freestream velocity. Free to oscillate in the in-line and cross-flow directions, the cylinder with an aspect ratio of 25 is pinned-pinned at both ends at a fixed wall-cylinder gap ratio G/D = 0.8, where D is the cylinder diameter. The cylinder yaw angle (α) is varied from 0° to 60° with an increment of 15°. The main focus is given on the influence of α on structural vibrations, flow patterns, hydrodynamic forces, and IP (Independence Principle) validity. The vortex shedding pattern, contingent on α, is parallel at α=0°, negatively-yawed at α ≤ 15° and positively-yawed at α ≥ 30°. In the negatively- and positively-yawed vortex shedding patterns, the inclination direction of the spanwise vortex rows is in the opposite and same directions of α, respectively. Both in-line and cross-flow vibration amplitudes are symmetric to the midspan, regardless of α. The RMS lift coefficient C_L,rms exhibits asymmetry along the span when α ≠ 0°, maximum C_L,rms occurring on the lower and upper halves of the cylinder for negatively- and positively-yawed vortex shedding patterns, respectively. The IP is well followed in predicting the vibration amplitudes and drag forces for α ≤ 45° while invalid in predicting lift forces for α ≥ 30°. The vortex-shedding frequency and the vibration frequency are well predicted for α = 0° - 60° examined.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.60-68
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• 2010

In this study, the conventional plane tip, double squealer tip, and various groove tip blades were tested in a linear cascade in order to measure the effect of the tip shapes on tip surface heat transfer coefficient distributions. Detailed heat transfer coefficient distributions were measured using a hue-detection based transient liquid crystals technique. Two tip gap clearances of 1.5% and 2.3% of blade span were investigated and the Reynolds number based on cascade exit velocity and chord length was $2.48{\times}10^5$. Results showed that the overall heat transfer coefficients on the tip surface with various grooved tips were lower than those with plane tip blade. The overall heat transfer coefficient on grooved along suction side tip was lower than that on the squealer tip.

• Structural Engineering and Mechanics
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• v.58 no.2
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• pp.199-216
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• 2016

A large number of bridges were built several decades ago, and most of which have gradually suffered serious deteriorations or damage due to the increasing traffic loads, environmental effects, and inadequate maintenance. However, very few studies were conducted to investigate the vibration behaviors of a damaged bridge under moving vehicles. In this paper, the vibration behaviors of such vehicle-bridge system are investigated in details, in which the effects of the concrete cracks and bridge surface roughness are particularly considered. Specifically, two vehicle models are introduced, i.e., a simplified four degree-of-freedoms (DOFs) vehicle model and a more complex seven DOFs vehicle model, respectively. The bridges are modeled in two types, including a single-span uniform beam and a full scale reinforced concrete high-pier bridge, respectively. The crack zone in the reinforced concrete bridge is considered by a damage function. The bridge and vehicle coupled equations are established by combining the equations of motion of both the bridge and vehicles using the displacement relationship and interaction force relationship at the contact points between the tires and bridge. The numerical simulations and verifications show that the proposed modeling method can rationally simulate the vibration behaviors of the damaged bridge under moving vehicles; the effect of cracks on the impact factors is very small and can be neglected for the bridge with none roughness, however, the effect of cracks on the impact factors is very significant and cannot be neglected for the bridge with roughness.

• Smart Structures and Systems
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• v.6 no.4
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• pp.373-388
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• 2010

The updated finite element model of K$\ddot{o}$m$\ddot{u}$rhan Highway Bridge on the Firat River located on the $51^{st}$ km of Elazi$\breve{g}$-Malatya highway is obtained by using analytical and experimental results. The 2D and 3D finite element model of the bridge is created by using SAP2000 structural analyses software, and the dynamic characteristics of the bridge are determined analytically. The experimental measurements are carried out by Operational Modal Analysis Method under traffic induced vibrations and the dynamic characteristics are obtained experimentally. The vibration data are gathered from the both box girder and the deck of the bridge, separately. Due to the expansion joint in the middle of the bridge, special measurement points are selected when experimental test setups constitute. Measurement duration, frequency span and effective mode number are determined by considering similar studies in literature. The Peak Picking method in the frequency domain is used in the modal identification. At the end of the study, analytical and experimental dynamic characteristic are compared with each other and the finite element model of the bridge is updated by changing some uncertain parameters such as material properties and boundary conditions. Maximum differences between the natural frequencies are reduced from 10% to 2%, and a good agreement is found between natural frequencies and mode shapes after model updating.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.4 no.1
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• pp.211-232
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• 1998

Because there were lots of side effects and tolerances to the existing anticancer therapeutics, the experiment extracting the anticancer effect from medicinal herbs is in progress liviely. Therefore the purpose of this study were to research the tendency and the course of anticancer studies. To research the tendency of anticancer studies, medicinal herbs of fifty three experimental papers were analyzed and to examine the course of studies, anticancer papers in the medical world were used. The obtained results were as follows: Methods of herbal medicinal treatments were elimination the pathogenic factor(祛邪) and supporting healthy energy(扶正) method used. In this study, immediately tumor bearing and immune response were the most important point. The subject of immediately tumor bearing was not in the specific cancer but in the influence on the life span of general cencerous cells. In the experimental study of immune response, the effect on NK cell activity of medicinal herbs most studied. The combined usage of medicinal herbs and anticancer agent mostly intended to know whether it inhibits the tumor cell growth. The serum test and blood cell number test show if medicinal herbs inhibit side effect of anticancer agent. More than 80 percents of used medicinal herbs, there were anticancer activities. However anticancer experimental studies using medicinal herbs two weak points. The one, it was difficult to choose a prescription according to differentiation of symptoms and signs(辨證論) of the Oriental Medicine, because we put to the test not a man but a mouse. The other, as we observed the indirect effect of the whole physiological regulation caused by synergic effects of the complex prescription, we don't understand the detailed mechanism of the herb. Therefore, if the anticancer effect of the herb is proved the experiment, we should research the concrete medical action of medicinal herbs and immunological analysis of herbal medicines to the body.

• Journal of Nutrition and Health
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• v.28 no.11
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• pp.1091-1099
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• 1995

The cyutotoxic effects of hot water soluble polysaccharides extract(PS) from the mushroom, Lentinus edodes, and in combinations with vitamin A or vitamin E on life span of ICR mice bearing P388 cancer cells and in vitro against P388 cancer cells were examined. The chemical components of PS and fractions were analyzed and survival time and cell number of P388 treated with extract fractions with and without vatamin A or E supplementation were also measured. The results obtained were summarized as follows; The extract of fraction B was shown to have the highest antitumor activity against P388 implanted in ICR mice. The antitumor fraction B was consisted of 82.0% of polysaccharide and 4.2% of protein. All three fractions seemed to have in vivo antitumor activity against P388, and fraction B showed the highest activity, In vitro P388 cell growht was inhibited 76%, 89%, 54% by the addition of fraction A, B and C respectively. Vitamin A or E did not appear to have any accelerating effects on either in vivo or in vitro cell cytotoxicity when each of them was combined with the PS and fractions. All three fractions contained more than 68% of polysaccharides. The fraction B showed the highest value of 88% in polysaccharides. Monsaccharides of the fraction B were identified as galactose(59.1%), glucose(29.2%), fructose(2.8%) and uronic acid(4.2%). Hydrolysis of protein from the fraction B was didentifed to have 17 kinds of defined and 5 undifined amino acids. The inhibitory effects of the hot water extracts from mushroom against cancer cell growth of P388 were stronger than the control group. And the survival time of ICR mice was shown to be 161% between the control group and the experimental groups.

• Journal of Acupuncture Research
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• v.35 no.2
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• pp.95-100
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• 2018

Background: The aim of this study is to assess the feasibility of acupuncture treatment for the management of subacute and chronic post-thoracotomy pain in patients with traumatic multiple rib fractures. Methods: A total of 30 participants who have undergone thoracotomy after traumatic multiple rib fractures will be recruited. Participants will be invited and equally randomised into acupuncture plus usual care and usual care alone groups. A computer-generated random number sequence will be used and concealed using opaque, sealed, sequentially numbered envelopes. Twelve sessions of manual and electrical acupuncture performed by Korean medicine doctors will be provided over a span of 3 months to participants allocated to the acupuncture group. Participants in the usual care group will continue pain medication, exercise and physical therapy as required. Study feasibility will be measured based on the proportion of patients who complete the measurement of pain at 12 or 24 weeks after baseline. The clinical outcomes will include; the average pain intensity over the recent week at rest, movement and cough, quality of life, patient's global assessment of recovery, respiratory function measured by the pulmonary function test and use of pain medication at 4, 8, 12 and 24 weeks after enrolment. Adverse events will be recorded for all participants. Written informed consent will be obtained from all participants. The local ethics committee has approved the study. This pilot trial will inform further studies investigating the potential role of acupuncture for subacute and chronic post-thoracotomy pain in patients with traumatic multiple rib fractures.

• Wind and Structures
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• v.20 no.2
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• pp.349-361
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• 2015

Higher-mode vertical vortex-induced vibrations (VIV) have been observed on several steel box-girder suspension bridges where different vertical modes are selectively excited in turn with wind velocity in accordance with the Strouhal law. Understanding the relationship of VIV amplitudes for different modes of vibration is very important for wind-resistant design of long-span box-girder suspension bridges. In this study, the basic rectangular cross-section with side ratio of B/D=6 is used to investigate the effect of different modes on VIV amplitudes by section model tests. The section model is flexibly mounted in wind tunnel with a variety of spring constants for simulating different modes of vibration and the non-dimensional vertical amplitudes are determined as a function of reduced velocity U/fD. Two 'lock-in' ranges are observed at the same onset reduced velocities of approximately 4.8 and 9.4 for all cases. The second 'lock-in' range, which is induced by the conventional vortex shedding, consistently gives larger responses than the first one and the Sc-normalized maximum non-dimensional responses are almost the same for different spring constants. The first 'lock-in' range where the vibration frequency is approximately two times the vortex shedding frequency is probably a result of super-harmonic resonance or the "frequency demultiplication". The main conclusion drawn from the section model study, central to the higher-mode VIV of suspension bridges, is that the VIV amplitude for different modes is the same provided that the Sc number for these modes is identical.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1218-1226
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• 1999

In decoding the turbo codes, the sliding window BCJR algorthm, derived from the BCJR algorithm, permits a continuous decoding of the coded sequence without requiring trellis fermination of the constituent codes and uses reduced memory span. However, the number of computation required is greater than that of BCJR algorithm and no study on the effect of the window length has been reported. In this paper, we propose an eddicient sliding window type scheme which maintains the advantages of the conventional sliding window algorithm, reduces its computational burdens, and improves is BER performance. A guideline is first presented to determine the proper window length and then a computationally efficient sliding window BCJR algorithm is obtained by allowing the window to be forwarded in multi-step. Simulation results show that the proposed scheme outperforms the conventional sliding window BCJR algorithm with reduced complexity. It gains 0.1dB SNR improvements over the conventional method for the constraint length 3 and BER $10^{-4}$