• Steel and Composite Structures
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• v.51 no.3
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• pp.305-323
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• 2024

Previous experimental studies have effectively demonstrated the remarkable efficiency of the stiffened channel link in connecting circular columns and I-shaped beams. This research aims to present design criteria and assess the seismic properties of this specific connection type through numerical modeling. Various parameters, including stiffener type and geometric properties of the stiffened channel element, were duly taken into account. The findings from over 136 nonlinear finite element analyses (FEAs) reveal that the recommended detailing scheme reliably satisfies all the regulations specified for rigid beam-to-column connections in special moment frames.

• Journal of Acupuncture Research
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• v.26 no.2
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• pp.125-145
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• 2009

Objectives : To analyze the inclusion criteria of participants, control group interventions, and the results of prior studies of acupuncture for OA. Also to identify aspects of the procedure that are associated with positive outcomes in order to establish ideal acupuncture treatment model. And to assess the methodological quality of the trials with modified Jadad score and FEAS in order to evaluate the quality of prior studies and find out whether or not acupuncture has a positive effect in treating OA. Methods : Articles up to the date of November 2008 were searched via computerized databases of PubMed, Journal of Korean Oriental Medicine, The Journal of Korean Acupuncture & Moxibustion Society and Journal of Oriental Rehabilitation Medicine. Bibliographies of reviewed papers were also searched and reviewed. Only randomized controlled trials (RCTs) and systematic reviews concerning the effects of acupuncture or electroacupuncture (EA) on symptoms of osteoarthritis of the human knee, published in English and Korean were included. The acupuncture treatment methods of the reviewed trials were assessed based on STRICTA. And the methodological quality of the trials was assessed by modified Jadad score and FEAS. Results : Twenty one trials of acupuncture for OA were analyzed. Based on the results of this review the following factors might contribute to optimal results from acupuncture treatment. 1) Usage of $ST_{35}$, $GB_{34$, $EX_{32}$, $ST_{36}$ and $SP_9$ acupuncture points. 2) More than four acupuncture points should be used. 3) More than 15 minutes of needle retention time. 4) Needle length-40mm and diameter-0.30mm 5) Usage of EA 6) more than 10 times treatment 7) Treatment frequency of more than once a week, 8) Treatment duration longer than 6 to 8 weeks. Conclusions : High quality clinical trials of Acupuncture for OA is still in lack. Future investigators must concentrate their attentions on the quality of acupuncture treatment itself used in the trials as well as the methodological quality of trials.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.186-194
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• 2011

The reinforced concrete beam-column connections are in lack of constructability and are likely to show anchorage failure because of the complex details of joint regions. Under seismic loads, a destruction of the column or the beam-column joint leads to collapse of the whole structures. For this reason, the safety of structures has to be guaranteed by following procedures which are based on the strong column-weak beam design concept: 1) failure of beam by generating plastic hinge in the beam maintained a certain distance from the surface of column, 2) failure of column or beam-column joint. In this study, headed bars were used as longitudinal reinforcements of beam and joint reinforcements in order to improve the strength and constructability of joint and to relocate plastic hinge. The finite element analyses (FEAs) were performed to the reinforced concrete beam-column joints utilizing headed bar reinforcements. To verify the availability of the analysis models, the FEAs for experimental tests performed by previous researchers were conducted and compared with the experimental results. Additional variables are also considered to confirm the excellence of headed bars. Analysis results indicate that the constructability of beam-column connections can be improved by using headed bars for the full anchorage of longitudinal reinforcements of beam under similar structural performance. In addition, the plastic hinge was relocated to the intended place by using headed bars as joint reinforcements. Under cyclic displacement loading, the energy dissipation capacity and ultimate stress were increased and the decrease in stiffness was minimized.

• Korean Journal of Materials Research
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• v.10 no.4
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• pp.295-300
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• 2000

Uniform silicon tip arrays were fabricated using the reactive ion etching followed by the reoxidation sharpening, and the effect of Pd-coated layer on electron emission characteristics was studied. The electron emission from Si field emitter arrays(FEAs) was a little, but improved by removing surface oxide on the FEA, but pronounced drastically by coating a $100-{\AA}-thick$ Pd metal layer. The turn-on voltage in the Pd-coated Si FEAs was reduced by 30 V in comparison with that in uncoated ones. This results from the increase of surface roughness at the tip apex by the Pd coating on Si FEA, via the decrease of the apex radius at which electrons are emitting. The Pd-coated emitters showed superior operating stability over a wide current range to that of the uncoated ones. This suggests that Pd coating enhances the high temperature stability and the surface inertness Si FEA.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.4005-4012
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• 2014

Background: This study investigated the utilization of both problem and emotion focused coping strategies and their association with aspects of quality of life among Turkish women with ovarian cancer undergoing chemotherapy. Materials and Methods: The convenience sample consisted of 228 patients in all disease stages. The data were collected using the brief COPE, QOL-Cancer patient tool, sociodemographic sheet, and medical variables were gathered from patients' medical charts. Results: Findings reveal that quality of life is moderately high for this group of cancer patients, despite some specific negative facets of the illness and treatment experience. Acceptance, emotional support and religion were the most frequently used problem-focused coping strategies and self-distraction, venting and behavioral disengagement were the most frequently used emotion-focused coping strategies reported by patients. Overall quality of life and, particularly, psychological and spiritual well-being scores of younger patients were lower. Patients reported using significantly more problem-focused coping than emotion-focused coping, and more problem-focused and less emotion-focused coping predicted greater quality of life. Problem-focused coping was related to patients' physical and spiritual well-being and emotion-focused coping was related inversely with psychological and social well-being. Conclusions: Coping strategies are influential in patient quality of life and their psychosocial adaptation to ovarian cancer. Psycho-oncology support programs are needed to help patients to frequent use of problem-focused coping and reduce emotion-focused coping strategies to improve overall quality of life.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.580-588
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• 2010

OPB(out-of-plane bending)-induced failure of mooring chain was firstly addressed by CALM (catenary anchor leg mooring)-type offloading buoy, located approximately one mile away from the bow of the Girassol FPSO which was installed offshore area of Angola in September 2001. This study deals with verifying the load transfer mechanism between the first free chain link and connected two chain links inside the chain hawse. OPB moment to angle variation relationships are proposed by extensive parametric study where the used design variables are static friction coefficients, proof test loads, nominal tension forces, chain link diameters, chain link grades and chain link types. The stress ranges due to OPB moments are obtained using nonlinear FEAs (finite element analyses). Final stress ranges are derived considering ones from IPT (in-plane tension) forces. Also a formula for OPB fatigue assessment is briefly introduced.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.33-37
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• 1999

We present, for the first time, a prototype active-matrix field emission display (AMFED) with 25$\times$25 pixels in which polycrystalline silicon fie이 emitter array (poly-Si FEA) and thin-film transistor (TFT) were monolityically intergrated on an insulating substrate. The FEAs showed relatively large electron emissions above at a gate voltage of 50 V, and the TFTs were designed to have low off-stage currents even though at high drain voltages. The intergrated poly-Si TFT controlled electron emissions of the poly-Si FEA actively, resulting in improvement in the emission stability and reliability along with a low-voltage control of field emission below 25V. With the prototype AMFED we have displayed character patterns by low-boltage pertipheral circuits of 15 V in a high vacuum chamber.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.782-785
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• 2007

We studied the effect of current-aging on field emission from carbon nanotubes field emitter arrays (CNT-FEAs) selectively patterned by the resist-assistan tpatterning(RAP) process. After sustaining the electric field when starting emission current density $(J_s)$ is $0.1\;mA/cm^2$ during 40 hrs, it was observed that the field emission property and uniformity were remarkably improved due to the elimination of oxygen atom and thus the reconstruction of carbon bonding at the tip of CNTs during field emission.

• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.212-216
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• 1997

A new metal tip fabrication process for low voltage operation is reported in this paper. The key element of the fabrication process is that isotropic silicon etching and oxidation process used in silicon tip fabrication is utilized for gate hole size reduction and gate oxide layer. A metal FEA with 625 tips was fabricated in order to demonstrate the validity of the new process and submicron gate apertures were successfully obtained from originally 1.7$\mu\textrm{m}$ diameter mask. The emission current above noise level was observed at the gate bias of 50V. The required gate voltage to obtain the anode current of 0.1${\mu}\textrm{A}$/tip was 74V and the emission current was stable above 2${\mu}\textrm{A}$/tip without any disruption. The local field conversion factor and the emitting area were calculated as 7.981${\times}$10\ulcornercm\ulcorner and 3.2${\times}$10\ulcorner$\textrm{cm}^2$/tip, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.7
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• pp.508-516
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• 1998

Mo-tip field emitter arrays(FEAs) were fabricated by conventional Spindt process and their life time characteristics and failure mode were evaluated. The fabricated Mo-tip FEA could generate at least $0.35\{mu} A/tip$ emission current for about 320 persistently under a constant gate bias of 140 V and was finally destroyed through self-healing mode. Thin diamond-like carbon films were coated on the M-tip by plasma-enhanced CVD and the dependence of emission properties upon the DLC thickness was investigated. By DLC coating, the turn-on voltage and emission current were appeared to be improved whereas the current fluctuation was increased in the DLC thickness range of $0~1,000\{AA}$.