• The Korean Journal of Cytopathology
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• v.1 no.2
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• pp.152-157
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• 1990

A 70-year-old female who was diagnosed as myxoid chondrosarcoma by fine needle aspiration of a pleural mass is described. She presented with left chest discomfort of 4 months' duration and aggravating dyspnea and chest pain for 2 months. Chest X-ray and CT scan revealed a large lobulated low density mass invading chest wall at the left pleural cavity and massive pleural fluid. Fine needle aspiration was done under the impression of mesothelioma or metastatic cancer. The aspirates from the mass were very cellular and composed of isolated or clustered forms of large plump cells. Abundant cytoplasm was blulsh opaque and the margin was rounded in the isolated cells, whereas clustered cells show ill-defined ceil borders and aggregating tendency. The nuclei were eccentric, round to ovoid, and had fine chromatin pattern and multiple small nucleoli. Cellular pleomorphism or mitotic figure was not definite. These findings were consistent with cytologic features of chondrosarcoma. Final diagnosis was confirmed as myxoid chondrosarcoma by mediastinoscopic biopsy and the tumor showed strong positivity for S-100 protein.

• Journal of the Korea Concrete Institute
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• v.27 no.5
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• pp.551-558
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• 2015

Lateral displacement in the most complex-shaped tall buildings is caused by eccentric gravity loads which are induced by the difference in location between a center of mass and a center of stiffness. The lateral displacements obtained from analysis, using conventional procedures, are prone to overestimate the actual values because much of realignment efforts made during construction phase are ignored. In construction sequence analysis, the self-leveling of slab and the verticality of columns/walls could be considered at each construction stage. Moreover, the displacement compensation can be achieved by manual process such as re-centering - locating to global coordinates through surveying. Because the lateral displacement increases with the building height, it is necessary to set up adjustment plan through construction stage analysis in advance in order to result in displacements less than the allowable limits. Because analytical solution includes lots of assumptions, the pre-adjusting displacement should be reasonably controlled with considerations for the uncertainty due to these assumptions.

• Earthquakes and Structures
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• v.18 no.1
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• pp.27-44
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• 2020

This work presents a comparison of three performance-based seismic design methods (PBSD) as applied to plane steel frames having eccentric braces (EBFs) and buckling restrained braces (BRBFs). The first method uses equivalent modal damping ratios (ξ_k), referring to an equivalent multi-degree-of-freedom (MDOF) linear system, which retains the mass, the elastic stiffness and responds in the same way as the original non-linear MDOF system. The second method employs modal strength reduction factors (${\bar{q}}_k$) resulting from the corresponding modal damping ratios. Contrary to the behavior factors of code based design methods, both ξ_k and ${\bar{q}}_k$ account for the first few modes of significance and incorporate target deformation metrics like inter-storey drift ratio (IDR) and local ductility as well as structural characteristics like structural natural period, and soil types. Explicit empirical expressions of ξ_k and ${\bar{q}}_k$, recently presented by the present authors elsewhere, are also provided here for reasons of completeness and easy reference. The third method, developed here by the authors, is based on a hybrid force/displacement (HFD) seismic design scheme, since it combines the force-base design (FBD) method with the displacement-based design (DBD) method. According to this method, seismic design is accomplished by using a behavior factor (q_h), empirically expressed in terms of the global ductility of the frame, which takes into account both non-structural and structural deformation metrics. These expressions for q_h are obtained through extensive parametric studies involving non-linear dynamic analysis (NLDA) of 98 frames, subjected to 100 far-fault ground motions that correspond to four soil types of Eurocode 8. Furthermore, these factors can be used in conjunction with an elastic acceleration design spectrum for seismic design purposes. Finally, a comparison among the above three seismic design methods and the Eurocode 8 method is conducted with the aid of non-linear dynamic analyses via representative numerical examples, involving plane steel EBFs and BRBFs.

• Biomedical Science Letters
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• v.17 no.2
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• pp.141-149
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• 2011

The purpose of this study was to find out any difference and correlation between the cardiac structure and its function according to the level of obesity as evaluated by waist measurement and BMI (body mass index) in healthy adults. For research subjects, the study selected a final 519 subjects excluding 198 subjects aged 55 or over out of 717 subjects who received echocardiography through a medical checkup at J General Hospital. For the criteria for obesity, men were defined as being obese in case their waist measurement was over 90 cm, whereas women were defined as being obese in case their waist measurement was over 80 cm. Also, regarding the BMI criteria, in case a person's BMI was 30 kg/$m^2$, the subject was classified as belonging to an obese group, and in case a person's BMI was between 25 kg/$m^2$ and 30 kg/$m^2$, the subject was classified as belonging to an overweight group. Concerning the evaluation of cardiac structure and function, they were evaluated using two-dimensional, M-mode, doppler echocardiography. According to the stage of obesity in accordance with waist measurement and BMI, the cardiac structure showed both eccentric and centripetal changes, and the cardiac function was also discovered to show differences according to the stage of obesity. In addition, also in the overweight group, which is a prior stage to obesity, out of the criteria for obesity classification according to BMI, there were differences in the cardiac structure and function. Also, both the waist measurement and BMI were found to have a correlation with cardiac structure and diastolic function. Consequently, cardiac structure and function are correlated with BMI and waist measurement, which are anthropometrical variables, and obesity is assumed to induce not only structural change but also functional change of the heart.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.181-190
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• 2007

The purpose of this study was to analyze the muscle fatigue for lower limbs during the level and downhill running. The subjects were 6 males of twenties who have no experience to get the injury in the lower limbs and required to run on the level and downhill which was -7% grade treadmill at 8.3km/h. EMG signal was gained by ME3000P8 Measurement Unit and computed the Median Frequency(MF) with the power spectrum analysis in the Megawin software. Rectus femoris(RF), Vastus lateralis(VL), Gluteus medius(GLU), Biceps Femoris(BF), gastrocnemius medial head(GM), gastrocnemius lateral head(GL), Tibialis anterior(TA) were selected. The result of this study were as follows: The MF of RF decreased in the downhill running than level running in length of time but, the MF of VL was opposite. The MF of BF decreased in the level and downhill running, but, the MF of BF decreased much in the level than downhill running. The MF of GLU decreased much in the downhill running but, almost no change in the level running. The MF of TA decreased in the level running than downhill running. The MF of GL decreased in the level running but, the MF of GM decreased in the downhill running in length of time. This study analyzed the muscle fatigue of the lower limbs with the median frequency on the basis of an assumption that the impact force for the flexion and extension of the joint and the body mass may be much in the eccentric contraction such as the downhill running than level running. RF and GM showed the muscle fatigue in the downhill running than level running. BF and GL showed the muscle fatigue in the level running than downhill running.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.359-364
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• 2013

In order to use a linear vibration motor for the actuator of a haptic interface, the motor must provide a higher reaction rate and longer service life than typical rotational motors with an eccentric mass. In this paper, we propose a linear vibration motor that is equipped with a voice-coil actuator and permanent-magnet springs. To concentrate the magnetic flux in the actuator, a Halbach-style magnetization pattern is used. Permanent-magnet springs replace mechanical springs to help increase the service life. We use the method of equivalent current sheets and the method of images to analyze and model the proposed vibration motor. These methods are validated using finite element analyses and experiments. A prototype motor is designed and fabricated. Tests with the prototype show the feasibility of the proposed linear vibration motor.

• Journal of fish pathology
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• v.11 no.1
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• pp.69-76
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• 1998

An apicomplexan parasite, Perkinsus sp. was observed from the cultured baby clams, Ruditapes philippinarum, collected from the coast of Kochang and Taean (South Korea), where it caused seasonal mortality of clams. Several milky-white cysts were observed on the surface of gill and visceral mass of parasitised clams. The trophozoites of parasite had eccentric nucleus and proliferated by schizogony in gill, mantle, hepatopancrease and reproductive tissues, resulting in the formation of granuloma and the intensive infiltration of hemocytes in the tissues. During incubation in FTM, trophozoites increased in size, resulting in prezoosporangia which appeared as round black spheres when colored with Lugols iodine solution. The prevalence of Perkinsus sp. in clams was Kochang, 73.1%; Taean, 94.8% (during 9-mo. survey) and showed size-dependent infection. Hemacolor kit was useful to reduce time for diagnosis of the trophozoite of Perkinsus sp. that has been responsible of massive motalities in the clam.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.8
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• pp.526-533
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• 2008

In this study, theoretical super screen vibration analysis has been carried out to predict the dynamic characteristics of interactive waste particles. In order to approach these problems, it is necessary to have a fundamental understanding the screening process and the process of both the remaining and the passed material on a screen with several interacting screen planes based on Soldinger(1999) was discussed. Here, the vibrating screen is composed of three assemblies such as screen, wastes guide, and supported screen as shown in Fig. 1. This model is regarded vibrator as the system of screen fixed tilt plates. Then materials(or particles) of different size is to be separated by using the eccentric vibrator and classifying tilt plates. As well moisturized construction wastes is more efficient to separate than moisture-less it. In processing separate mechanism, the more materials is light, the more staying time is long. Thus much lighter construction wastes(wood, Styrofoam, etc) and heavier materials are separated by staying time delay in a super screen. The design results, separation screen were able to know that small and larger particles are conspicuous difference each motion character according to trajectory particles, and small particles raise the probability in classifying tilt plates.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.41.3-42
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• 2016

New CCD photometric observations of GX Aur have been made between 2004 and 2015. Our light curves are the first ever compiled and display the variable O'Connell effect. The light variations are satisfactorily modeled by including time-varying cool-spots on the component stars. Our light curve synthesis indicates that the eclipsing pair is an A-type contact binary with parameters of i = 81.1 deg, ${\Delta}T=36K$, q = 0.950 and f = 46%. Including our 25 timing measurements, a total of 83 times of minimum light spanning about 66 yr were used for a period study. It was found that the orbital period of GX Aur has varied due to two periodic oscillations superposed on an upward-opening parabolic variation. The long-term period increase rate is deduced as $+9.636{\times}10^{-10}d\;yr^{-1}$, which can be produced as a mass transfer from the secondary star to the primary at a rate of $3.136{\times}10^{-6}M_{\odot}\;yr^{-1}$, among the largest rates for contact systems. The periods and semi-amplitudes of the two periodic variations are about $P_3=8.7yr$ and $P_4=21.2yr$, and $K_3=0.011d$ and $K_4=0.017d$, respectively. The most reasonable explanation for both cycles is a pair of light-travel-time effects driven by the possible existence of an unseen third and fourth components with projected masses of $M_3=0.91M_{\odot}$ and $M_4=1.09M_{\odot}$ in eccentric orbits of $e_3=0.13$ and $e_4=0.73$. Because no third light was detected in the light curve synthesis, each circumbinary object could be a compact star or a binary itself.

• Smart Structures and Systems
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• v.26 no.3
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• pp.373-390
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• 2020

Hybrid simulation (HS) is a versatile tool for structural performance evaluation under dynamic loads. Although real structural responses are often multiple-directional owing to an eccentric mass/stiffness of the structure and/or excitations not along structural major axes, few HS in this field takes into account structural responses in multiple directions. Multi-directional loading is more challenging than uni-directional loading as there is a nonlinear transformation between actuator and specimen coordinate systems, increasing the difficulty of suppressing loading error. Moreover, redundant actuators may exist in multi-directional hybrid simulations of large-scale structures, which requires the loading strategy to contain ineffective loading of multiple actuators. To address these issues, lately a new strategy was conceived for accurate reproduction of desired displacements in bi-directional hybrid simulations (BHS), which is characterized in two features, i.e., iterative displacement command updating based on the Jacobian matrix considering nonlinear geometric relationships, and force-based control for compensating ineffective forces of redundant actuators. This paper performs performance validation and application of this new mixed loading strategy. In particular, virtual BHS considering linear and nonlinear specimen models, and the diversity of actuator properties were carried out. A validation test was implemented with a steel frame specimen. A real application of this strategy to BHS on a full-scale 2-story frame specimen was performed. Studies showed that this strategy exhibited excellent tracking performance for the measured displacements of the control point and remarkable compensation for ineffective forces of the redundant actuator. This strategy was demonstrated to be capable of accurately and effectively reproducing the desired displacements in large-scale BHS.