• 제목/요약/키워드: Self-bias.

검색결과 309건 처리시간 0.03초

피쉬바인 모델을 이용한 커피전문점의 소비자 태도에 관한 연구 - 부산지역 대학생을 중심으로 - (A study on Consumer Attitude to a Coffee Shop Using the Fishbein Attitude Model - Focused on college students in Busan -)

  • 김유정;김광지;박기용
    • 한국조리학회지
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    • 제17권5호
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    • pp.30-41
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    • 2011
  • 본 연구는 피쉬바인 모델과 IPA를 이용하여 커피전문점의 소비자 태도를 분석하였다. 설문지는 2010년 12월 6일부터 12월 20일 까지 배포하였으며 200부중에서 175부를 회수하였다. 이후 불성실한 설문지 27부를 제외한 148부를 최종분석에 사용하였다. IPA 결과 매력적인 건물외형, 화장실 청결, 커피 신선도, 커피 맛은 좋은 성과유지 부분이며 커피 가격은 노력집중 영역에 있으며 커피 전문점 관리자는 이 부분을 개선해야 한다. 또한, 피쉬바인 모델을 통한 분석결과 커피 맛, 매력적인 건물외형, 화장실 청결, 커피 신선도 순으로 중요하게 나타났으며 스타벅스, 엔젤리너스, 커피빈, 파스쿠찌 순으로 선호하는 것으로 나타났다. 본 연구는 커피전문점 관리자에게 매우 의미 있는 시사점을 제안하고 있으며 자기기입법에 대한 한계점을 나타내고 있다.

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Properties Optimization for Perovskite Oxide Thin Films by Formation of Desired Microstructure

  • Liu, Xingzhao;Tao, Bowan;Wu, Chuangui;Zhang, Wanli;Li, Yanrong
    • 한국세라믹학회지
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    • 제43권11호
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    • pp.715-723
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    • 2006
  • Perovskite oxide materials are very important for the electronics industry, because they exhibit promising properties. With an interest in the obvious applications, significant effort has been invested in the growth of highly crystalline epitaxial perovskite oxide thin films in our laboratory. And the desired structure of films was formed to achieve excellent properties. $Y_1Ba_2Cu_3O_{7-x}$ (YBCO) superconducting thin films were simultaneously deposited on both sides of 3 inch wafer by inverted cylindrical sputtering. Values of microwave surface resistance R$_2$ (75 K, 145 GHz, 0 T) smaller than 100 m$\Omega$ were reached over the whole area of YBCO thin films by pre-seeded a self-template layer. For implementation of voltage tunable high-quality varactor, A tri-layer structured SrTiO$_3$ (STO) thin films with different tetragonal distortion degree was prepared in order to simultaneously achieve a large relative capacitance change and a small dielectric loss. Highly a-axis textured $Ba_{0.65}Sr_{0.35}TiO_3$ (BST65/35) thin films was grown on Pt/Ti/SiO$_2$/Si substrate for monolithic bolometers by introducing $Ba_{0.65}Sr_{0.35}RuO_3$ (BSR65/35) thin films as buffer layer. With the buffer layer, the leakage current density of BST65/35 thin films were greatly reduced, and the pyroelectric coefficient of $7.6\times10_{-7}$ C $cm^{-2}$ $K^{-1}$ was achieved at 6 V/$\mu$m bias and room temperature.

새로운 구조의 스위치형 이중 모드 전압 제어 발진기 (A New Switchable Dual Mode Voltage Controlled Oscillator)

  • 류지열;길버트
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2005년도 추계종합학술대회
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    • pp.869-872
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    • 2005
  • 본 논문에서는 새로운 구조의 스위치형 이중 모드 전압 제어 발진기 (VCO, Voltage Controlled Oscillator)를 제안한다. 이러한 회로는 이중 모드 동작, 즉 2.4GHz 및 5GHz에서 아주 효율적이며, 자체 바이어스 조정 회로를 포함한다. 스위칭 동작은 MOS 트랜지스터를 이용하며, 튜닝은 MOS 바랙터를 이용한다. 이는 TSMC 0.18${\mu}$m CMOS 공정을 이용하여 설계되어 있고, 1.8V 전원전압에서 동작한다. 전체적인 튜닝 범위는 5GHz에서 13%, 2.4GHz에서 8%의 결과를 보였다. 또한 5 GHz에 대해 1MHz 오프셋에서 약 -102dBc/Hz의 위상 잡음을, 2.4 GHz에 대해서는 약- 89dBc/Hz의 위상 잡음을 보였다. 제작된 전압제어 발진기는 5GHz 모두에서는 2mA, 2.4 GHz 모드에서는 2.5mA의 꼬리 전류 특성을 보였다.

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MOSFET형 바이오 센서를 이용한 디옥시 니발레놀의 검출 (Detection of deoxynivalenol using a MOSFET-based biosensor)

  • 임병현;권인수;이희호;최영삼;신장규;최성욱;전향숙
    • 센서학회지
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    • 제19권4호
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    • pp.306-312
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    • 2010
  • We have detected deoxynivalenol(DON) using a metal-oxide-semiconductor field-effect-transistor(MOSFET)-based biosensor. The MOSFET-based biosensor is fabricated by a standard complementary metal-oxide-semiconductor(CMOS) process, and the biosensor's electrical characteristics were investigated. The output of the sensor was stabilized by employing a reference electrode that applies a fixed bias to the gate. Au which has a chemical affinity for thiol was used as the gate metal to immobilize a self-assembled monolayer(SAM) made of 16-mercaptohexadecanoic acid(MHDA). The SAM was used to immobilize anti-deoxynivalenol antibody. The carboxyl group of the SAM was bound to the anti- deoxynivalenol antibody. Anti-deoxynivalenol antibody and deoxynivalenol were bound by an antigen-antibody reaction. In this study, it is confirmed that the MOSFET-based biosensor can detect deoxynivalenol at concentrations as low as 0.1 ${\mu}g$/ml. The measurements were performed in phosphate buffered saline(PBS; pH 7.4) solution. To verify the interaction among the SAM, antibody, and antigen, surface plasmon resonance(SPR) measurements were performed.

레이저 유기 형광법을 이용한 자기장이 인가된 유도결합플라즈마의 전기장 특성 연구

  • 송재현;김혁;정재철;황기웅
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.474-474
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    • 2010
  • 현재 반도체시장의 확장으로 인해서 기존의 300mm 웨이퍼에서 450mm의 웨이퍼를 사용하는 공정으로 변화하는 추세이다. 450mm 웨이퍼로 대면적 화되면서 기존 300mm 공정 때보다 훨씬 효율적인 플라즈마 소스 즉, 고밀도이고, 고균등화(high uniformity) 플라즈마 소스를 필요로 한다. 본 논문에서는 고밀도 플라즈마 소스인 유도 결합형 플라즈마(Inductively Coupled Plasma ; ICP)에 축 방향의 약한 자기장을 인가시킨 자화된 유도결합형 플라즈마(Magnetized Inductively Coupled Plasma : MICP)[1]를 제안하여 기존 ICP와의 차이점을 살펴보았다. 실험 방법으로 레이저 유기 형광법(Laser Induced Fluorescence : LIF)[2]을 이용하여 플라즈마 쉬스(Sheath) 내의 전기장을 외부 자기장의 변화에 따라 높이별로 측정하고 그 결과로부터 쉬스의 전기적 특성을 살펴보았다. 플라즈마의 특성상 탐침이나 전극에 전압을 인가하면 그 주위로 디바이 차폐(Debye Shielding)현상이 일어나서 플라즈마 왜곡이 일어난다. 그렇기에 플라즈마, 특히 플라즈마 쉬스의 특성을 파악하기 위해서 레이저라는 기술을 사용하였다. 레이저는 고가의 장비이고 그 사용에 많은 경험지식(know-how)를 필요로 하지만 플라즈마를 왜곡시키지 않고, 플라즈마의 밀도, 온도, 전기장 등 많은 상수(parameter)들을 얻어 낼 수 있다. 또한 3차원적으로 높은 분해능을 가지고 있는 장점이 있다. 강한 전기장이 있는 곳에서 입자들의 고에너지 준위가 전기장의 세기에 비례하여 분리되는 Stark effect[3] 이론을 이용하여 플라즈마 쉬스내의 전기장을 측정하였다. 실험은 헬륨가스 700mTorr 압력에서 이루어졌다. 기판의 파워를 50W에서 300W까지 변화시키면서 기판에 생기는 쉬스의 전기장의 변화를 살펴보았고, 자기장을 인가한 후 동일한 실험을 하여 자기장의 유무에 따른 플라즈마 쉬스의 전기장 변화를 살펴보았다. 실험결과 플라즈마 쉬스의 전기장의 변화는 기판의 파워와 플라즈마 밀도에 크게 의존함을 알았다. 기판의 파워가 커질수록 쉬스의 전기장은 커지고, 기판에 생기는 Self Bias Voltage역시 음의 방향으로 커짐을 확인 하였다. 또한 자기장을 걸어주었을 경우 쉬스의 두께가 얇아짐으로써 플라즈마의 밀도가 증가했음을 확인 할 수 있었다.

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The Effect of Plasma Gas Composition on the Nanostructures and Optical Properties of TiO2 Films Prepared by Helicon-PECVD

  • Li, D.;Dai, S.;Goullet, A.;Granier, A.
    • Nano
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    • 제13권10호
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    • pp.1850124.1-1850124.12
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    • 2018
  • $TiO_2$ films were deposited from oxygen/titanium tetraisopropoxide (TTIP) plasmas at low temperature by Helicon-PECVD at floating potential ($V_f$) or substrate self-bias of -50 V. The influence of titanium precursor partial pressure on the morphology, nanostructure and optical properties was investigated. Low titanium partial pressure ([TTIP] < 0.013 Pa) was applied by controlling the TTIP flow rate which is introduced by its own vapor pressure, whereas higher titanium partial pressure was formed through increasing the flow rate by using a carrier gas (CG). Then the precursor partial pressures [TTIP+CG] = 0:027 Pa and 0.093 Pa were obtained. At $V_f$, all the films exhibit a columnar structure, but the degree of inhomogeneity is decreased with the precursor partial pressure. Phase transformation from anatase ([TTIP] < 0.013 Pa) to amorphous ([TTIP+CG] = 0:093 Pa) has been evidenced since the $O^+_2$ ion to neutral flux ratio in the plasma was decreased and more carbon contained in the film. However, in the case of -50 V, the related growth rate for different precursor partial pressures is slightly (~15%) decreased. The columnar morphology at [TTIP] < 0.013 Pa has been changed into a granular structure, but still homogeneous columns are observed for [TTIP+CG] = 0:027 Pa and 0.093 Pa. Rutile phase has been generated at [TTIP] < 0:013 Pa. Ellipsometry measurements were performed on the films deposited at -50 V; results show that the precursor addition from low to high levels leads to a decrease in refractive index.

산화아연 나노막대가 내장된 아산화구리 박막 구조를 이용한 산화물 광양극 제작 및 광전기화학적 특성 (Fabrication and Photoelectrochemical Properties of an Oxide Photoanode with Zinc Oxide Nanorod Array Embedded in Cuprous Oxide Thin Film)

  • 민병국;김효진
    • 한국재료학회지
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    • 제29권3호
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    • pp.196-203
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    • 2019
  • We report on the fabrication and characterization of an oxide photoanode with a zinc oxide (ZnO) nanorod array embedded in cuprous oxide ($Cu_2O$) thin film, namely a $ZnO/Cu_2O$ oxide p-n heterostructure photoanode, for enhanced efficiency of visible light driven photoelectrochemical (PEC) water splitting. A vertically oriented n-type ZnO nanorod array is first prepared on an indium-tin-oxide-coated glass substrate via a seed-mediated hydrothermal synthesis method and then a p-type $Cu_2O$ thin film is directly electrodeposited onto the vertically oriented ZnO nanorod array to form an oxide p-n heterostructure. The introduction of $Cu_2O$ layer produces a noticeable enhancement in the visible light absorption. From the observed PEC current density versus voltage (J-V) behavior under visible light illumination, the photoconversion efficiency of this $ZnO/Cu_2O$ p-n heterostructure photoanode is found to reach 0.39 %, which is seven times that of a pristine ZnO nanorod photoanode. In particular, a significant PEC performance is observed even at an applied bias of 0 V vs $Hg/Hg_2Cl_2$, which makes the device self-powered. The observed improvement in the PEC performance is attributed to some synergistic effect of the p-n bilayer heterostructure on the formation of a built-in potential including the light absorption and separation processes of photoinduced charge carriers, which provides a new avenue for preparing efficient photoanodes for PEC water splitting.

환자기반 치과의료 환자안전에 대한 연구 (Development of patient-based patient safety questionnaire in dentistry)

  • 김보라;신호성
    • 대한치과의료관리학회지
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    • 제10권1호
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    • pp.53-65
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    • 2022
  • The Primary Care Patient Measure of Safety (PC-PMOS) is a measure of safety that allows patients to evaluate contributing factors related to patient safety in primary care. This study aimed to examine which questionnaire items of the PC-PMOS could be used in Korean dental institutions. A survey of the Korean translation of the PC-PMOS, a self-reported questionnaire, was conducted in August 2022 by 400 adults who had used dental-care services within the last three years. Of the 77 items, 34 were selected using principal component analysis and two experts' evaluations based on face validity. Five domains were identified from factor analysis: patient centeredness, patient information update, complaint processing, communication, and information about the complaint process. The Cronbach's alpha of the data was 0.913, indicating high reliability. As a result of the generalized multiple regression analysis, regression coefficients were not statistically significant, except for household income. This indicated that there was no bias in the patient safety scores of dental institutions evaluated by patients within the range of independent variables used in this study. The five domains with 34 items identified in this study suggested the factors that contribute to the safety of patients who used dental care services in Korea. However, validation of this study result is still important to refine questionnaires suitable for dental institutions in Korea so as to further improve the quality of dental care.

코로나바이러스감염증-19로 인한 두려움, 사회적 거리두기가 여성의 자살 생각에 미치는 영향: 우울의 매개효과 (Effects of Fear of Coronavirus Disease 2019 and Social Distancing on Women's Suicidal Ideation: Mediating Effect of Depression)

  • 김효연;박한종
    • 대한간호학회지
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    • 제52권4호
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    • pp.464-475
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    • 2022
  • Purpose: This study aimed to identify the mediating effects of depression amid the influence of fear and social distancing arising from Coronavirus disease 2019 (COVID-19) in Korean women's suicidal ideation. Methods: A descriptive correlation study was conducted. Study participants, recruited by Hankook Research from March 2 to March 5, 2021, included 300 women aged 19 to 49 living in South Korea, and 100 people were randomly allocated and enlisted for each age group out of 700,000 Hankook Research Panels recruited in advance from 17 cities and provinces nationwide. Data were collected through a self-reported questionnaire and analyzed using Pearson's correlation coefficient and Hayes' Process Macro Model 4 with 95% bias-corrected bootstrap confidence interval via SPSS statistics 27.0. Results: Suicidal ideation was significantly correlated with fear of COVID-19 (r = .16, p = .006) and depression (r = .65, p < .001). The mediation effect of depression in the relationship between the fear of COVID-19 and suicidal ideation was found to be significant (B = 0.40, boot 95% CI: 0.21~0.61). However, social distancing did not significantly affect suicidal ideation via depression (B = - 0.79, boot 95% CI: - 1.94~0.26). Conclusion: It is necessary to develop and apply interventions to prevent depression and suicidal behaviors by continuously observing and reducing the negative psychological responses caused by COVID-19.

Healthy lifestyle interventions for childhood and adolescent cancer survivors: a systematic review and meta-analysis

  • Kyung-Ah Kang;Suk Jung Han;Jiyoung Chun;Hyun-Yong Kim;Yerin Oh;Heejin Yoon
    • Child Health Nursing Research
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    • 제29권2호
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    • pp.111-127
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    • 2023
  • Purpose: This study investigated the effects of healthy lifestyle interventions (HLSIs) on health-related quality of life (HR-QoL) in childhood and adolescent cancer survivors (CACS). Methods: Major databases were searched for English-language original articles published between January 1, 2000 and May 2, 2021. Randomized controlled trials (RCTs) and non-RCTs were included. Quality was assessed using the revised Cochrane risk-of-bias tool, and a meta-analysis was conducted using RevMan 5.3 software. Results: Nineteen studies were included. Significant effects on HR-QoL were found for interventions using a multi-modal approach (exercise and education) (d=-0.46; 95% confidence interval [CI]=-0.84 to -0.07, p=.02), lasting not less than 6 months (d=-0.72; 95% CI=-1.15 to -0.29, p=.0010), and using a group approach (d=-0.46; 95% CI=-0.85 to -0.06, p=.02). Self-efficacy showed significant effects when HLSIs provided health education only (d=-0.55; 95% CI=-0.92 to -0.18; p=.003), lasted for less than 6 months (d=-0.40; 95% CI=-0.69 to -0.11, p=.006), and were conducted individually (d=-0.55; 95% CI=-0.92 to -0.18, p=.003). The physical outcomes (physical activity, fatigue, exercise capacity-VO2, exercise capacity-upper body, body mass index) revealed no statistical significance. Conclusion: Areas of HLSIs for CACS requiring further study were identified, and needs and directions of research for holistic health management were suggested.