• Journal of Korean Physical Therapy Science
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• 제10권1호
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• pp.90-101
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• 2003

Gait analysis can provide a better understanding of how the alignment of the lower limb and foot can contribute to force observed at the knee. Anatomic and mechanical factors that affect loading in the knee pint can contribute to pathologic change seen at the knee in degenerative pint disease and should be considered in treatment plan. The purpose of this study is to present the gait analysis data and to determine whether there is any relationships between alignment of the lower limb, foot progression angle and knee pint moments in elderly healthy women with 3-dimensional motion analyzer. The results were as follows; 1. Cadence showed 114.8 steps/min, gait speed showed 1.05 m/s, time per a stride showed 1.06 sec, time per a step showed 0.53 sec, single-supporting phase was 0.41 sec, double-supporting phase was 0.24 sec, stride length was 1.04 m, Step length was 0.56 m. 2. According to the parameters of kinematics, the maximal knee flexion angle through swing phase showed left $46.82^{\circ}$, right $40.19^{\circ}$ and the maximal knee extension angle showed left $-1.32^{\circ}$, right $2.01^{\circ}$. knee varus showed left $26.90^{\circ}$, right $30.93^{\circ}$. 3. Moment, one of kinetic parameters of knee pint the maximal flexion moment showed left 0.363. Nm/kg, right 0.464 Nm/kg and maximal extension moment showed left 0.389 Nm/kg, right 0.463 Nm/kg. The maximal. adduction moment showed left 0.332 Nm/kg, right 0.379 Nm/kg and the maximal internal rotatory moment showed left 0.13 Nm/kg, right 0.140 Nm/kg. 4. On sagittal plane, the maximal power of knee joint showed left 0.571 J/kg, right 0.629 J/kg. On coronal plane, the maximal power of knee joint showed left 0.11 J/kg, right 0.12 J/kg. On transverse plane, the maximal power of knee joint showed left 0.058 J/kg, right 0.072 J/kg. 5. The subject who had varus alignment of the lower extremity had statistically higher in knee adduction moment in mid stance phase. 6. The subject who had large foot progression angle had statistically lower in knee adduction moment in late stance phase. A relationship was observed between the alignment of the lower extremity and the adduction moment of the knee joint during stance phase. Hence, we need some research to figure, out the change of adduction moment according to the sort of knee joint osteoarthritis and the normal geriatrics as well. And we also require more effective, specific therapeutic program by making use of those background of researches.

• Wind and Structures
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• 제28권4호
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• pp.255-270
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• 2019

Aerodynamic configurations of bridge decks have significant effects on the aerostatic torsional divergence and flutter forsuper long-span bridges, which are onset for selection of suitable bridge decksfor those bridges. Based on a cable-stayed bridge with double main spans of 1500 m, considering typical twin-box, stiffening truss and closed-box section, which are the most commonly used form of bridge decks and assumed that the rigidity of those section is completely equivalent, are utilized to investigate the effects of aerodynamic configurations of bridge decks on aerodynamic instability performance comprised of the aerostatic torsional divergence and flutter, by means of wind tunnel tests and numerical calculations, including three-dimensional (3D) multimode flutter analysis and nonlinear aerostatic analysis. Regarding the aerostatic torsional divergence, the results obtained in this study show twin-box section is the best, closed-box section the second-best, and the stiffening truss section the worst. Regarding the flutter, the flutter stability of the twin-box section is far better than that of the stiffening truss and closed-box section. Furthermore, wind-resistance design depends on the torsional divergence for the twin-box and stiffening truss section. However, there are obvious competitive relationships between the aerostatic torsional divergence and flutter for the closed-box section. Flutter occur before aerostatic instability at initial attack angle of $+3^{\circ}$ and $0^{\circ}$, while the aerostatic torsional divergence occur before flutter at initial attack angle of $-3^{\circ}$. The twin-box section is the best in terms of both aerostatic and flutter stability among those bridge decks. Then mechanisms of aerostatic torsional divergence are revealed by tracking the cable forces synchronous with deformation of the bridge decksin the instability process. It was also found that the onset wind velocities of these bridge decks are very similar at attack angle of $-3^{\circ}$. This indicatesthat a stable triangular structure made up of the cable planes, the tower, and the bridge deck greatly improves the aerostatic stability of the structure, while the aerodynamic effects associated with the aerodynamic configurations of the bridge decks have little effects on the aerostatic stability at initial attack angle of $-3^{\circ}$. In addition, instability patterns of the bridge depend on both the initial attack angles and aerodynamic configurations of the bridge decks. This study is helpful in determining bridge decksfor super long-span bridges in future.

• Journal of the Korean Geophysical Society
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• 제5권4호
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• pp.321-328
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• 2002

Difficulties encountered in downhole S-wave (shear wave) surveys include the precise determination of shear wave travel times and determination of geophone orientation relative to the direction of polarization caused by the seismic source. In this study an S-wave enhancing and a principal component analysis method were adopted as a tool for determination of S-wave arrivals and the direction of polarization from downhole S-wave survey data. An S-wave enhancing method can almost double the amplitudes of S-waves, and the angle between direction of polarization and a geophone axis can be obtained by a principal component analysis. Once the angle is obtained data recorded by two horizontal geophones are transformed to principal axes, yielding so called scores. The scores gathered along depth are all in-phase, consequently, the accuracy of S-wave arrival picking could be remarkably improved. Applying this processing method to the field data reveals that the test site consists of a layered ground earth structure.

• Journal of Ocean Engineering and Technology
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• 제6권2호
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• pp.21-34
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• 1992

The behavior of fatigue crack growth in the single spot welded joint of zinc galvanized steel sheets was studied experimentally and analytically based on fracture mechanics. Axial tension fatigue tests were carried out with the BSxGAB specimen that the bare plane(GAB) of monogalvanized steel sheet was spot welded to the double thickness bare steel sheet(BS), and with the GAxGAB specimen that the galvanized plane (GA) was spot welded to the equal thickness bare plane (GAB) 1. The relation between maximum stress intensity factor, K sub(max) and the number of cycles to failure, N sub(f) has shown a linear relation on log-log plot in the spot weld of the zinc galvanized steel sheet. 2. The fatigue strength of BSxGAB specimens is about 23% higher than that of GAxGAB specimens at the fatigue strength of $1\times10^6$ cycles. And the fatigue life of BSxGAB specimens at the same load range increases 6~9 times higher than that of GAxGAB specimens. 3. The general tendency at the angle of bending($\theta$) in an applied load has changed rapidly at the initial 20% of its life. After then, it has changed slowly. The change at the angle of bending has increased linearly as the load range increases. 4. It has shown a linear relation between the location ratio of initiation ${\gamma}$ and fatigue life $N_f$ on the semi-log graph paper. Here $\gamma$ means that the crack distance between main crack and sub-crack, 2L is divided by the nugget diameter, 2r. $\gamma=a{\cdot}log N_f+n$ (where a and n are material constant.)

• Clinics in Shoulder and Elbow
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• 제19권4호
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• pp.229-236
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• 2016

Background: Cubitus varus and cubitus valgus deformities are common complications of distal humeral fractures in children. We evaluated the usefulness of supracondylar dome osteotomy as a treatment option for adults with cubitus varus or valgus deformity developed during childhood. Methods: Ten patients who had received supracondylar dome osteotomy and stabilization with plates to treat cubitus varus or valgus deformity between July 2006 and August 2013 were included in this study. Their mean age at the time of surgery was $36.50{\pm}10.22years$. The mean follow-up duration was $54.80{\pm}32.50months$. We evaluated humerus-elbow-wrist angles (HEWA), improvements in the lateral prominence index (LPI) or medial prominence index (MPI), Mayo elbow performance scores (MEPS), and overall results in accordance with the Banerjee criteria. Results: For the six patients with cubitus varus, the mean postoperative HEWA, mean correction angle, and mean improvement in LPI were $9.72^{\circ}{\pm}3.95^{\circ}$, $27.67^{\circ}{\pm}10.75^{\circ}$, and $6.92%{\pm}3.40%$, respectively. For the four patients with cubitus valgus, the mean postoperative HEWA, mean correction angle, and mean improvement in MPI were $14.73^{\circ}{\pm}2.97^{\circ}$, $11.55^{\circ}{\pm}3.26^{\circ}$, and $11.33%{\pm}6.39%$, respectively. There was no significant difference between postoperative and preoperative mean MEPS. The subjective ulnar nerve symptoms were alleviated in all patients. The overall results were excellent in six and good in four patients. Conclusions: This study suggests that supracondylar dome osteotomy with secure fixation using double plates may be useful in correcting cubitus varus or cubitus valgus deformity, yielding good functional outcomes in adults.

• Earthquakes and Structures
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• 제12권1호
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• pp.1-12
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• 2017

Historical earthquakes have shown that successive seismic events may occur in regions of high seismicity. Such a sequence of earthquakes has the potential to increase the damage level of the structures, since any rehabilitation between the successive ground motions is practically impossible due to lack of time. Few studies about this issue can be found in literature, most of which focused their attention on the seismic response of SDOF systems or planar frame structures. The aim of the present study is to examine the impact of seismic sequences on the damage level of 3D multistorey R/C buildings with various structural systems. For the purposes of the above investigation a comprehensive assessment is conducted using three double-symmetric and three asymmetric in plan medium-rise R/C buildings, which are designed on the basis of the current seismic codes. The buildings are analyzed by nonlinear time response analysis using 80 bidirectional seismic sequences. In order to account for the variable orientation of the seismic motion, the two horizontal accelerograms of each earthquake record are applied along horizontal orthogonal axes forming 12 different angles with the structural axes. The assessment of the results revealed that successive ground motions can lead to significant increase of the structural damage compared to the damage caused by the corresponding single seismic events. Furthermore, the incident angle can radically alter the successive earthquake phenomenon depending on the special characteristics of the structure, the number of the sequential earthquakes, as well as the distance of the record from the fault.

• Korean Journal of Crystallography
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• 제15권1호
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• pp.1-4
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• 2004

The title compound, $C_{18}H_{20}O_5S$, crystallized in the centrosymmetric space group $P\={1}$ with one molecule in an asymmetric unit. The S atom in the sulfonate group retains the overall tetrahedral environment of the O and C atoms with an average S-O bond of 1.420(2) ${\AA}$ for double bond and of 1.598(2) ${\AA}$ for single bond and S-C length of 1.742(3) ${\AA}$. The torsion angle C(7)-S-O(3)-C(8) is 100.3(2)$^{\circ}$ and the dihedral angle of the two planar six-membered rings is 42.73(20)$^{\circ}$.

• The Journal of the Acoustical Society of Korea
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• 제35권5호
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• pp.340-348
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• 2016

Ray-based model for the calculation of the ocean surface-generated ambient noise coherence function has the form of double integral with respect to a range and a bearing angle. While the theoretical consideration about its numerical implementations was partly given in the past work of authors, the numerical results on the ocean environment have not been presented yet. In this paper, we perform numerical experiments for shallow and deep water environments. It is shown that the coherence function depends on the ocean sediment sound speed, and is more sensitive to the ocean sediment sound speed in the shallow water than in the deep water. Similar trend is also observed for varying the orientation of hydrophone pair. In addition, a post-processing technique is proposed in order to plot the noise intensity for the noise receiving angle. This procedure will supplement the weakness of the ray-based model about the output data type compared to the semi-analytic model of Harrison.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제14권5호
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• pp.179-187
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• 2014

As an Accident data recorder (ADR) is a system to record a vehicle's status and dynamics information on the before and after of accident, Traffic accident investigation agencies and parts developers have a lot of interest to analyze an accident objectively and develop automotive safety devices by using real accident data, This study is to analyze an accident objectively and scientifically on the basis of traffic accident reconstruction with the use of output data of an event data recorder. This study is conducted double lane change test six times and slalom test one time as a field driving test and simulation. Based on the vehicle speed, the longitudinal and transverse acceleration, steering angle, driving path, and other kinds of information obtained from the field driving test, this study performed a simulation with PC-Crash program of reenacting and analyzing a traffic accident. The simulation was performed twice in the acceleration-steering angle input method and in the acceleration-driving path input method. By comparing the result of the field driving test with the results of the two simulations, we drew an analysis method with the optimal path reconstruction.

• Wind and Structures
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• 제30권2호
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• pp.181-198
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• 2020

In the traditional buffeting response analysis method, the spanwise incomplete correlation of buffeting forces is always assumed to be same as that of the incident wind turbulence and the action of the signature turbulence is ignored. In this paper, three typical bridge decks usually adopted in the real bridge engineering, a single flat box deck, a central slotted box deck and a two-separated paralleled box deck, were employed as the investigated objects. The wind induced pressure on these bridge decks were measured via a series of wind tunnel pressure tests of the sectional models. The influences of the wind speed in the tests, the angle of attack, the turbulence intensity and the characteristic distance were taken into account and discussed. The spanwise root coherence of buffeting forces was also compared with that of the incidence turbulence. The signature turbulence effect on the spanwise root coherence function was decomposed and explained by a new empirical method with a double-variable model. Finally, the formula of a sum of rational fractions that accounted for the signature turbulence effect was proposed in order to fit the results of the spanwise root coherence function. The results show that, the spanwise root coherence of the drag force agrees with that of incidence turbulence in some range of the reduced frequency but disagree in the mostly reduced frequency. The spanwise root coherence of the lift force and the torsional moment is much larger than that of the incidence turbulence. The influences of the wind speed and the angle of attack are slight, and they can be ignored in the wind tunnel test. The spanwise coherence function often involves several narrow peaks due to the signature turbulence effect in the high reduced frequency zone. The spanwise coherence function is related to the spanwise separation distance and the spanwise integral length scales, and the signature turbulence effect is related to the deck-width-related reduced frequency.