• Composites Research
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• 제22권1호
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• pp.15-21
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• 2009

본 논문에서는 편향각을 갖는 직물 복합재료 시편을 제작하여 정적 압축실험과 피로실험을 수행하고 그 결과를 비교하였다. 직물구조의 차이에 따른 압축거동을 평가하기 위해 동일한 섬유와 기지로 구성된 일방향 복합재료와 평직 복합재료의 적층순서를 동일하게 조절한 시편을 준비하였다. 정적 압축실험을 통해 편향각을 갖는 시편의 강성과 강도를 측정하였고, 측정된 강도를 바탕으로 압축강도 예측식을 제안하였다. 피로실험을 통해 복합재료의 직물 구조의 차이에 의한 피로수명의 변화를 관찰하였으며, 편향각의 변화와 하중조건에 따른 피로수명의 차이를 비교하였다.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.141-155
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• 2016

본 연구는 중년기 성인의 뇌졸중 관련 건강지식, 낙관적 편견 및 건강증진 생활양식 정도와 관계를 파악하고, 건강증진 생활양식에 미치는 효과를 파악하기 위한 서술적 조사연구이다. 연구기간은 2015년 7월 15일부터 8월 15일이며, 연구대상자는 40세 이상 60세 미만의 성인 191명이며, 자료 수집은 구조화된 설문지를 이용한 자가 보고식으로 이루어졌다. 자료분석은 PASW Statistics 21.0과 AMOS 21.0 프로그램을 사용하였으며, 분산분석, 상관성분석, 구조방정식 모형 분석 등을 실시하였다. 중년기 성인은 뇌졸중 위험요인으로 흡연과 고혈압을 당뇨병보다 높게 인식하였으며, 뇌졸중에 대한 낙관적 편견은 미미하였다. 뇌졸중 관련 건강지식은 낙관적 편견(r=-.143, p=.048), 건강증진 생활양식(r=.268, p=<.001)과 상관관계가 있었고, 낙관적 편견은 건강증진 생활양식의 대인관계 및 스트레스 행위(r=.177, p=.014)와 상관관계가 있었다. 또한 뇌졸중 관련 건강지식이 낙관적 편견보다 건강증진 생활양식에 더 큰 영향을 미치는 것으로 확인하였다. 결론적으로 중년기 성인의 뇌졸중에 관한 능동적인 정보획득과 건강 지식, 낙관적 편견이 뇌졸중 관련 건강증진 생황양식에 중요한 요인임을 알 수 있었다. 그러므로 중년기 성인의 뇌졸중 관련 건강증진 생활양식을 향상시키기 위한 교육 프로그램에는 뇌졸중 관련 건강지식을 높이고, 낙관적 편견을 감소시킬 수 있는 방안이 고려되어야 할 것이다.

• 융합보안논문지
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• 제21권1호
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• pp.201-208
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• 2021

본 연구의 목적은 북한에 대한 인지편향(기준점편향)을 지닌 집단 간의 통일인식 차이에 대해서 설문조사 결과를 바탕으로 한 실증적 연구를 통해 알아보는 것이다. 북한과 관련된 학교교육이 제공하는 내용의 차이에 따라 인지편향(기준점편향)이 발생하고, 형성된 관점에 따라 통일인식에 차이가 발생할 수 있다는 가정 하에 연구가 진행되었다. 실증적 연구를 위해 서울대학교 통일평화연구원에서 주관한 통일인식 조사 자료를 활용하였으며, 인지편향이 상이한 두 개의 그룹은 청소년기 학교에서 주로 접했던 분야를 "반공과 안보"로 선택한 집단(A그룹)과 "통일이익, 다문화, 북한 이해"를 문항에서 선택한 집단(B그룹)을 기준으로 구분되었다. 분석결과 A그룹은 성인이 되어서도 북한을 적대의 대상으로 인식하고, B그룹은 대화와 협력의 대상으로 여기는 인지편향(기준점편향)이 나타났다. 이에 따라 A그룹은 B그룹에 비해 통일이 우리나라에 긍정적인 이득이 된다는 의견에 동의하는 비율이 상대적으로 낮았으며, 북한과의 타협과 대화에 대한 호응도도 낮았다. 하지만 북한 이탈주민에 대한 수용도 측면에서는 두 그릅 간의 유의한 차이는 발생하지 않았다. 본 연구결과는 초기 학교교육이 성인 이후의 통일인식에 영향을 미친다는 점에서 학교 통일교육 방향에 참조가 될 수 있을 것이다.

• Journal of Advanced Marine Engineering and Technology
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• 제20권5호
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• pp.103-113
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• 1996

The properties of the deposited film depend on the deposition condition and these, in turn depend critically on the morphology and crystal orientation of the films. Therefore, it is important to clarify the nucleation occurrence and growth stage of the morphology and orientation of the film affected by deposition parameters, e.g. the gas pressure and bias voltage etc. In this work, magnesium thin flims were prepared on cold-rolled steel substrates by a thermo-eletron activation ion plating technique. The influence of nitrogen gas pressure and substrate bias voltage on their crystal orientation and morphology of the coated films were investigated by scanning electron microscopy (SEM) and X-ray diffraction, respectively. The diffraction peaks of magnesium film became less sharp and broadened with the increase of nitrogen gas pressure. With an increase in nitrogen gas pressure, flim morphology changed from colum nar to granular structure, and surface crystal grain-size decreased. The morphology of films depended not only on gas pressure but also on bias voltage, i.e., the effect of increasing bias voltage was similar to that of decreasing gas pressure. The effect of crystal orientation and morphology of magnesium films on corrosion behaviors was estimated by measuring anodic polarization curves in deaerated 3%NaCl solution. Magnesium, in general, has not a good corrosion resistance in all environments. However, these magnesium films prepared by changing nitrogen gas pressure showed good corrosion resistance. Among the films, magnesium films which exhibited granular structure had the highest corrosion resistance. The above phenomena can be explained by applying the effects of adsorption, occlusion and ion sputter of nitrogen gas.

• 대한한방부인과학회지
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• 제34권3호
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• pp.137-156
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• 2021

Objectives: The purpose of this study is to assess the effect of taking herbal medicine for the postpartum lactation. Methods: We searched 9 databases for recent three years, that contained four english, two chinese, one japanese and two korean database from September 17, 2016 to December 31, 2020. Randomized controlled trials (RCTs) were eligible. Measurement of outcome included total curative effective rate, volume of lactation, volume of milk supplement, and serum prolactin concentration. The risk of bias was assessed by two independent authors using the Cochrane risk of bias tool. Results: Total 725 of studies was screened, 11 RCTs were finally selected. Number of participants per study ranged from 60 to 257. The treatment group of taking a herbal medicine is effective for improving total curative effective rate, volume of lactation, volume of milk supplement, and serum prolactin concentration compared with control group. Because most of the studies had considerable heterogeneity in terms of type of intervention and comparison for outcome measurement, meta analysis for quantitative analysis was impossible. Conclusions: This studies showed that taking a herbal medicine is effective on increasing volume of lactation and speeding up the start of the first breastfeeding. However, included studies suffered from incomplete reporting, high or unclear risk of bias and substantial heterogeneity between studies. In the Future, further high-quality RCTs are needed to prove effectiveness of herbal medicine for breastfeeding and reduce the risk of bias.

• 한방안이비인후피부과학회지
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• 제36권3호
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• pp.74-98
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• 2023

Objectives : This study aims to evaluate the add-on effect of herbal bath combined with acitretin in patients with psoriasis. Methods : We searched randomized controlled trials(RCTs) reporting the effect of herbal bath and acitretin combined treatment for psoriasis in 10 electronic databases from their inception to January 2023. Study collection, data extraction, and risk of bias assessment were performed by two independent researchers. Data synthesis and risk of bias evaluation was conducted using Revman 5.4. Results : Ten RCTs with 1,008 subjects were included. Herbal bath and acitretin combined treatment group showed higher average total effective rate than acitretin alone group(RR 1.39; 95% CI: 1.15-1.68, P=0.0006, I² =0%). Herbal bath and additional treatments such as phototherapy(NB-UVB) and oral herbal medicine, combined with acitretin group also showed higher average total effective rate than acitretin alone group(RR 1.81; 95% CI: 1.47-2.22, P<0.00001, I² =43%). Herbal bath and phototherapy(NB-UVB) combined with acitretin group also showed higher average total effective rate than acitretin alone group(RR 1.51; 95% CI: 1.18-1.93, P=0.0009, I² =0%). The overall risk of bias of the included studies was unclear or of high risks. Conclusions : This review showed that the add-on of herbal bath combined with acitretin treatment could be more effective than acitretin alone treatment in patients with psoriasis. However, because of few included studies, heterogeneity between studies, and insufficient quality of included studies, further well-designed RCTs are needed to confirm the add-on effect of herbal bath on psoriasis.

• ETRI Journal
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• 제15권2호
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• pp.11-25
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• 1993

Interface trap densities at gate oxide/silicon substrate ($SiO_2/Si$) interfaces of metal oxide semiconductor field-effect transistors (MOSFETs) were determined from the substrate bias dependence of the subthreshold slope measurement. This method enables the characterization of interface traps residing in the energy level between the midgap and that corresponding to the strong inversion of small size MOSFET. In consequence of the high accuracy of this method, the energy dependence of the interface trap density can be accurately determined. The application of this technique to a MOSFET showed good agreement with the result obtained through the high-frequency/quasi-static capacitance-voltage (C-V) technique for a MOS capacitor. Furthermore, the effective substrate dopant concentration obtained through this technique also showed good agreement with the result obtained through the body effect measurement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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• pp.234-239
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• 1992

Design live load and girder distribution factors play an important role in the current design procedures. The fraction of vehicle load effect transferred to a single member may be selected in accordance with current KBDC. However, the specified values, both design load and distribution factors involve considerable inaccuracies, These inaccuracies relate to the uncertainties of the structural analysis, especially any bias and scatter which drives from the use of simplified load distribution factors. In this study , based on several field measurement and finite element analysis, live load distribution effects of current KBDC are evaluated. The final values of the bias and coefficient of variation of "g"according to bridge type are determined. The bridge types are reinforced concrete slab, prestressed concrete girder and steel l-beam.el l-beam.

• Transactions on Electrical and Electronic Materials
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• 제12권2호
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• pp.43-50
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• 2011

Carbon-nanotube metal oxide semiconductor field effect transistor (CN-MOSFET) is a promising future device candidate. The electrical characteristics of 16 nm N-type CN-MOSFETs are explored in this paper. The optimum N-type CN-MOSFET device profiles with different number of tubes are identified for achieving the highest on-state to off-state current ratio ($I_{on}/I_{off}$). The influence of substrate voltage on device performance is also investigated in this paper. Tradeoffs between subthreshold leakage current and overall switch quality are evaluated with different substrate bias voltages. Technology development guidelines for achieving high-speed, low-leakage, area efficient, and manufacturable carbon nanotube integrated circuits are provided.

• 한국대기환경학회지
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• 제21권2호
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• pp.269-274
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• 2005

In this work, analytical bias arising from the gas chromatographic determination of sulfur compounds was evaluated by the application of direct loop injection method to the GC/PFPD detection of four sulfur compounds including H$_{2}$S, CH$_{3}$SH, DMS, and DMDS. For the proper evaluation of analytical uncertainties involved in GC calibration, we employed two comparative techniques of calibration at fxed concentration injection (CFCI) vs calibration at fixed volume injection (CFVI) method. The results of our study indicate that CFCI method exhibits very poor sensitivity due to the matrix effect with varying injection volumes. On the other hand, as CFVI method overcomes such limitation, it can be used to obtain very accurate quantification of S compounds at their high concentration levels above a few to a few tens ppb.