• Composites Research
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• v.29 no.2
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• pp.85-89
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• 2016

This paper aims at estimating the fracture behavior at the bonded part of composite material. CFRP is manufactured as the type of TDCB. The static analysis of Mode 1 due to the configuartion factor of m is carried out. Four kinds of specimens have the configuartion factor(m) of 2, 2.5, 3 and 3.5. As the study result, the displacements at specimens are shown to be similar each other in these four cases. At m of 3.5, the reaction force becomes highest as 412 N and is shown to be improved as much as 14% by comparing m of 2. The data on defection of the bonded interface and reaction force are thought to be contributed to the structural design of CFRP and the safe design.

• Structural Engineering and Mechanics
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• v.9 no.5
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• pp.449-467
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• 2000

The natural frequencies and the corresponding mode shapes of a non-uniform beam carrying multiple point masses are determined by using the analytical-and-numerical-combined method. To confirm the reliability of the last approach, all the presented results are compared with those obtained from the existing literature or the conventional finite element method and close agreement is achieved. For a "uniform" beam, the natural frequencies and mode shapes of the "clamped-hinged" beam are exactly equal to those of the "hinged-clamped" beam so that one eigenvalue equation is available for two boundary conditions, but this is not true for a "non-uniform" beam. To improve this drawback, a simple transformation function ${\varphi}({\xi})=(e+{\xi}{\alpha})^2$ is presented. Where ${\xi}=x/L$ is the ratio of the axial coordinate x to the beam length L, ${\alpha}$ is a taper constant for the non-uniform beam, e=1.0 for "positive" taper and e=1.0+$|{\alpha}|$ for "negative" taper (where $|{\alpha}|$ is the absolute value of ${\alpha}$). Based on the last function, the eigenvalue equation for a non-uniform beam with "positive" taper (with increasingly varying stiffness) is also available for that with "negative" taper (with decreasingly varying stiffness) so that half of the effort may be saved. For the purpose of comparison, the eigenvalue equations for a positively-tapered beam with five types of boundary conditions are derived. Besides, a general expression for the "normal" mode shapes of the non-uniform beam is also presented.

• Research in Plant Disease
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• v.8 no.4
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• pp.224-227
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• 2002

From the necrotic stem of aquaculture Dracaena for living room decoration, we observed conidia on acervuli with occasional setae and perithecia in vivo. Morphological characters were; acervuli, dark brown and 300-500 ${\mu}{\textrm}{m}$ in diameter; conidia, hyaline, aseptate, cylindrical to slightly ellipsoid with rounded apex and narrow truncate base on phialidic conidiophores, 12.5-17.5 ${\mu}{\textrm}{m}$; setae, variable in length 1-4 septate, slightly swollen at the base and tapered to the apex, 200 ${\mu}{\textrm}{m}$; appressoria, dark brown ovate to obovate irregular 5-12.5 ${\mu}{\textrm}{m}$, perithecia on decayed stem, globose, dark brown and black 85-300 ${\mu}{\textrm}{m}$; asci 8 spored, clavate to cylindrical; 50-62.5$\times$8-10 ${\mu}{\textrm}{m}$; ascospores, oval to fusiform, sometimes slightly curved, aseptate, hyaline. Above characteristics were also confirmed in vitro. Colletotrichum state of this fungus was also compared with C. lindemuthianum and C. musae in terms of morphology of conidia and setae and growth on PDA etc. This fungus was identified as Glomerella cingulata(Stonem.) Spaulding & Schrenk(Colletotrichum gloeosporioides(Penz. Sacc.).

• Tunnel and Underground Space
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• v.21 no.3
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• pp.164-173
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• 2011

In the present study, the stability of a compressed air energy storage cavern was numerically assessed by concrete plug shapes in order to investigate the optimal shape of concrete plug. The concrete plugs were cylindrical, embedded cylindrical, tapered, and wedged in shape. The stability assessment was carried out based on factor of safety through a strength reduction method and a volume ratio which refers to the ratio of the volume of yield regions in concrete induced by internal pressure to all concrete volume. The results from the present study indicated that the embedded cylindrical and taper shaped plugs were mechanically more stable than the cylindrical and wedge shaped plugs. However, from a comparison of stress distributions in rock mass between the embedded cylindrical and taper shaped plugs, the taper shaped plug was found to be more optimal than the embedded cylindrical plug, since the embedded cylindrical plug caused more stress concentration in the interface between the plug and rock mass than the taper shaped plug.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.431-434
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• 2005

A 2-year-old castrated male, Cocker spaniel dog with a history of chronic productive cough for 2 to 3 months and with unsuccessful treatment was referred to Veterinary Medical Teaching Hospital, Seoul National University. On thoracic radiographs, there were alveolar infiltrations at left cranial and right caudal lung fields, and soft-tissue opacity round to oval images at overall lung field. The bronchi were dilated, tortuous and not tapered. Abnormal air was accumulated focally in the caudodorsal lung fields. To scrutinize the soft-tissue opacity image and accumulated air, computed tomography (CT) was done. On CT images, severe cylindrical or tubular bronchiectasis was confirmed. And the soft-tissue opacity images were found in the dilated bilated and thought to complexes of mucous plugs, inflammatory cells, necrotic and fibrotic tissue. The dog was dead next day to the CT scan, so necropsy and histopathologic examination were perfermed. On the histopathology, there were cylindrical bronhiectasis and severe diffuse chronic fibrinous necropurulent bronchitis and bronchopneumonia. In this case, it was difficult to diagnose the bronchiectasis only with radiography due to the concurrent lesions, such as pulmonary infiltrations and mucous plugs, which was identified by computed tomography. Thus, computed tomography is considered as a useful modality to confirm tile bronchiectasis camouflaged by the concurrent lesion.

• Journal of The Korean Astronomical Society
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• v.51 no.2
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• pp.27-36
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• 2018

In a solar coronagraph, the most important component is an occulter to block the direct light from the disk of the sun. Because the intensity of the solar outer corona is $10^{-6}$ to $10^{-10}$ times of that of the solar disk ($I_{\odot}$), it is necessary to minimize scattering at the optical elements and diffraction at the occulter. Using a Fourier optic simulation and a stray light test, we investigated the performance of a compact coronagraph that uses an external truncated-cone occulter without an internal occulter and Lyot stop. In the simulation, the diffracted light was minimized to the order of $7.6{\times}10^{-10}I_{\odot}$ when the cone angle ${\theta}_c$ was about $0.39^{\circ}$. The performance of the cone occulter was then tested by experiment. The level of the diffracted light reached the order of $6{\times}10^{-9}I_{\odot}$ at ${\theta}_c=0.40^{\circ}$. This is sufficient to observe the outer corona without additional optical elements such as a Lyot stop or inner occulter. We also found the manufacturing tolerance of the cone angle to be $0.05^{\circ}$, the lateral alignment tolerance was $45{\mu}m$, and the angular alignment tolerance was $0.043^{\circ}$. Our results suggest that the physical size of coronagraphs can be shortened significantly by using a cone occulter.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.1963-1970
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• 2014

Ambient particulate matters($PM_{10}$ and $PM_{2.5}$) were investigated at GNTECH university in Jinju city. Samples were collected using a dichotomous sampler(series 240, Andersen Corp.) and a TEOM(Tapered Element Oscillating Microbalance) monitor period from November 2012 to October 2013. For the dichotomous sampler measurements, daily 24-h integrated $PM_{2.5}$ and $PM_{10-2.5}$ ambient air samples were collected at a total flow rate of 16.7 L /min. For the TEOM monitor measurements, daily 1-h integrated $PM_{10}$ ambient air samples were collected at a flow rate of 16.7 L /min. The annual average concentrations of $PM_{10-2.5}$ and $PM_{2.5}$ by a dichotomous sampler were $10.0{\pm}6.1{\mu}g/m^3$ and $22.6{\pm}9.3{\mu}g/m^3$, respectively. And $PM_{10}$ concentration by dichotomous sampler were similar to TEOM monitor by $32.7{\pm}12.9{\mu}g/m^3$ and $31.7{\pm}11.3{\mu}g/m^3$, respectively. And good correlation ($R^2=0.964$) between the two methods was observed. The annual average of $PM_{2.5}/PM_{10}$ ratio was $0.70{\pm}0.12$.

• Anxiety and mood
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• v.2 no.2
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• pp.101-107
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• 2006

Object : Since autonomic nerve system dysfunction was known as the mechanism of panic disorder, many researchers used heart rate variability (HRV) as means of measuring autonomic nerve function of patients with panic disorder. We aimed to examine the effect of paroxetine medication for 3 months on symptom improvement and change of heart rate variability of the patients with panic disorder. Methods : The subjects were patients with panic disorder who visited the psychiatric outpatient clinic of Samsung Medical Center in Seoul. We included panic disorder patients who were aged from 20 to 50 and in normal BMI range (from 18 to 30) to minimize the effect of age and weight on HRV data. We excluded the patients with EKG abnormalities, hypertension or other major psychiatric disorders. They took 20-40 mg paroxetine medication a day for 3 months. Alprazolam was used only during the first month to control the acute panic symptoms and was tapered off after that. We measured the acute panic inventory (API), Hamilton rating scale for anxiety and depression (HAM-A & HAM-D), Spielberger state-trait anxiety inventory (STAIS, STAIT), and Beck depression inventory (BDI) in order to assess clinical improvement of the patients. And we measured time and frequency domain HRV in the resting, standing and cognitive stress states to assess the change of HRV. All measurements were done before and after paroxetine treatment. Result : After paroxetine medication, patients showed significant improvement in all psychiatric scales. In time domain of HRV, standard deviations of all R-R intervals (SDNN) were significantly increased in all states. In frequency domain of HRV, the ratio of high frequency to total power (HF/TP) in the standing state was significantly increased. Conclusion : After 3 months paroxetine medication, panic disorder patients showed significant clinical improvement and change in HRV data such as SDNN in all states and HF/TP ratio in the standing state. This result suggests that paroxetine medication is effective for the improvement of autonomic nerve system dysfunction in panic disorder patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.8
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• pp.731-736
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• 2016

Three-dimensional (3D) high-aspect-ratio (HAR) microstructures for biomedical applications (e.g., microneedle, microadhesive, etc.) are microfabricated using the hybrid ultraviolet (UV) lithography in which inclined, rotational, and reverse-side UV exposure processes are combined together. The inclined and rotational UV exposure processes are intended to fabricate tapered axisymmetric HAR microstructures; the reverse-side UV exposure process is designed to sharpen the end tip of the microstructures by suppressing the UV reflection on a bottom substrate which is inevitable in conventional UV lithography. Hybrid UV lithography involves fabricating 3D HAR microstructures with an epoxy-based negative photoresist, SU-8, using our customized UV exposure system. The effects of hybrid UV lithography parameters on the geometry of the 3D HAR microstructures (aspect ratio, radius of curvature of the end tip, etc.) are measured. The dependence of the end-tip shape on SU-8 soft-baking condition is also discussed.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.99-102
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• 2016

Tubulointerstitial nephritis and uveitis (TINU) syndrome is a rare disease, often underdiagnosed or misdiagnosed in children. We describe the case of a 12-year-old boy who presented to Severance Hospital with a 1-month history of bilateral conjunctival injection. He was first evaluated by an Ophthalmologist in another hospital and diagnosed with panuveitis. Laboratory tests indicated renal failure, and a renal biopsy confirmed the diagnosis of acute tubulointerstitial nephritis. An extensive exclusion of all possible causes allowed a diagnosis of TINU syndrome. The patient was treated with a systemic corticosteroid (initially prednisolone, 2 mg/kg and later deflazacort 1 mg/kg) and topical steroid drops for 1 month. Azathioprine was later added to the treatment regimen and the systemic steroid was slowly tapered. The final outcome of renal-ocular disease was favorable in the patient. However, long-term follow-up is necessary to properly manage frequent relapses and incomplete renal recovery. TINU should be considered as a differential diagnosis in children with uveitis or acute renal failure.