• Steel and Composite Structures
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• 제51권3호
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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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• 제26권2호
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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.

• 한국구조물진단유지관리공학회 논문집
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• 제15권3호
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• pp.186-194
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• 2011

철근콘크리트 보-기둥 접합부는 철근의 복합적인 배근으로 인하여 시공성이 저하되고 철근의 정착공간이 협소하여 정착파괴가 발생할 가능성이 높다. 또한 지진하중 하에서 기둥 또는 접합부의 파괴는 구조물 전체의 파괴를 야기할 수 있기 때문에 기둥 표면에서 일정한 거리이상 떨어진 보에 소성힌지를 발생시켜 보의 파괴가 선행된 후에 기둥 및 접합부가 파괴되는 강기둥-약보의 설계 개념을 적용하여 구조물의 안전성을 확보하고 있다. 본 연구에서는 이러한 접합부의 강도 증가 및 시공성 향상을 도모하고 소성힌지를 보의 내측방향으로 이동시키기 위한 방안으로 보 주인장 철근과 접합부 보강 철근으로 헤디드 바를 활용하고자 하였다. 이를 위해 헤디드 바로 보강된 철근콘크리트 보-기둥 접합부에 대해 3차원 유한요소 해석을 수행하였다. 해석결과의 정확성을 검증하기 위하여 선행연구자에 의해 실험된 부재와 동일한 변수에 대한 해석을 수행하여 그 결과를 비교하였으며, 헤디드바의 우수성을 확인하기 위한 변수를 추가하여 해석을 수행하였다. 해석결과 보 주인장 철근의 정착방법으로 헤디드 바를 사용함으로써 유사한 구조성능 하에서 시공성 향상을 도모할 수 있음을 확인하였다. 또한 헤디드 바를 접합부에 보강함으로써 설계자가 의도한 위치에 소성힌지를 발생시킬 수 있었으며, 주기하중 하에서 에너지 소산능력의 증가, 강성 감소의 최소화 및 극한응력을 향상시키는 결과를 얻었다.

• 한국재료학회지
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• 제10권4호
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• pp.295-300
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• 2000

반응성 이온 식각과 산화막을 이용한 첨예화 공정을 통하여 균일한 실리콘 팁 어레이를 제작한 후, 그 위에 Pd을 증착하여, Pd 코팅이 전계 방출특성에 미치는 영향에 대해 조사하였다. 어레이에 존재하는 표면 산화막을 제거한 후의 전계 방출 특성의 향상은 매우 작았으나, $100{\AA}$의 Pd을 코팅한 후에는 30V의 구동전압이 감소하는 등 전계 방출특성이 크게 향상되었다. 이는 Pd 코팅에 의해 팁의 표면 거칠기가 증가하고, 전자가 방출되는 팁 끝부분의 반경이 감소하였기 때문이다. 한편 Pd을 코팅한 에미터는 높은 방출 전류 영역에서 우수한 동작 안전성을 보였다. 이를 통하여 Pd이 코팅된 실리콘 에미터가 고온에서의 동작과 표면안정성에서 우수한 특성을 보임을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권9호
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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.

• 대한조선학회논문집
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• 제47권4호
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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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• 제3권1호
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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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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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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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• 제2권6호
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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.

• 한국전기전자재료학회논문지
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• 제11권7호
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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 $0~1,000\{AA}$.