• Title/Summary/Keyword: Data dependence

Search Result 1,282, Processing Time 0.029 seconds

Full Parametric Impedance Analysis of Photoelectrochemical Cells: Case of a TiO2 Photoanode

  • Nguyen, Hung Tai;Tran, Thi Lan;Nguyen, Dang Thanh;Shin, Eui-Chol;Kang, Soon-Hyung;Lee, Jong-Sook
    • Journal of the Korean Ceramic Society
    • /
    • v.55 no.3
    • /
    • pp.244-260
    • /
    • 2018
  • Issues in the electrical characterization of semiconducting photoanodes in a photoelectrochemical (PEC) cell, such as the cell geometry dependence, scan rate dependence in DC measurements, and the frequency dependence in AC measurements, are addressed, using the example of a $TiO_2$ photoanode. Contrary to conventional constant phase element (CPE) modeling, the capacitive behavior associated with Mott-Schottky (MS) response was successfully modeled by a Havriliak-Negami (HN) capacitance function-which allowed the determination of frequency-independent Schottky capacitance parameters to be explained by a trapping mechanism. Additional polarization can be successfully described by the parallel connection of a Bisquert transmission line (TL) model for the diffusion-recombination process in the nanostructured $TiO_2$ electrode. Instead of shunt CPEs generally employed for the non-ideal TL feature, TL models with ideal shunt capacitors can describe the experimental data in the presence of an infinite-length Warburg element as internal interfacial impedance - a characteristic suggested to be a generic feature of many electrochemical cells. Fully parametrized impedance spectra finally allow in-depth physicochemical interpretations.

Extending Application of the 'Hardcore' Definition to Smokeless Tobacco Use: Estimates from a Nationally Representative Population in India and its Implications

  • Jena, Pratap Kumar;Bandyopadhyay, Chandan;Mathur, Manu Raj;Das, Sagarika
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.12
    • /
    • pp.5959-5963
    • /
    • 2012
  • Background: The term 'hardcore' has been applied to use of smoking tobacco and generally referred to as the inability or unwillingness of regular smokers to quit. The component constructs of hardcore except nicotine dependence are product neutral. With the use of 'time to first chew' as a measure of nicotine dependence, hardcore definition can be extended to characterize smokeless tobacco users. Hardcore users respond less to tobacco cessation interventions, and are prone to tobacco induced diseases including cancer. Thus identifying hardcore users would help in estimate the burden of high risk population for tobacco induced diseases. Smokeless tobacco use is predominant and accounts for more than 50% of oral cancer in India. Hence, hardcore chewing information could be used for planning of tobacco and cancer control interventions. The objective of this study was to assess the prevalence and associated factors of hardcore smokeless tobacco use in India. Materials and Methods: Global Adult Tobacco Survey (GATS)-India 2010 data were analyzed to quantify hardcore smokeless tobacco use in India with following five criteria: (1) current daily smokeless tobacco use; (2) no quit attempt in the past 12 months of survey or last quit attempt of less than 24 hours duration; (3) no intention to quit in next 12 months or not interested in quitting; (4) time to first use of smokeless tobacco product within 30 minutes of waking up; and (5) knowledge of smokeless tobacco hazards. Results: The number of hardcore smokeless tobacco users among adult Indians is estimated to be 5% (39.5 million). This group comprises 23.2% of daily smokeless tobacco users. The population prevalence varied from 1.4-9.1% across different national regions of India. Logistic regression modeling indicated age, education and employment status to be the major predictors of hardcore smokeless tobacco use in India. Conclusions: The presence of a huge number (39.5 million) of hardcore smokeless tobacco users is a challenge to tobacco control and cancer prevention in India. There is an unmet need for a universal tobacco cessation programme and intensification of anti-tobacco education in communities.

Temperature Dependence of Magnetoimpedance Effect in Amorphous $Co_{66}Fe_4Ni_1B_{14}Si_{15}$ (온도에 따른 비정질 금속$Co_{66}Fe_4Ni_1B_{14}Si_{15}$ 의 자기 임피던스 효과)

  • 김용국;김택기;김성일;이희복
    • Journal of the Korean Magnetics Society
    • /
    • v.8 no.1
    • /
    • pp.21-26
    • /
    • 1998
  • The temperature dependence of the magnetoimpedance (MI) effect is important both for scientific study and for thermal stability of MI sensor. We have performed the measurement of MI effect in amorphous $Co_{66}Fe_1Ni_1B_{14}Si_{15}$ (Metglas 2714 A) ribbon from a cryogenic chamber where the temperature of the sample can vary from 10 K to 300 K. The ac current was fixed at 10 mA for all measured frequencies ranging from 100 KHz to 10 MHz. The magnetoimpedance ratio (MIR) was revealed the drastic increment as a function of MIR (T) = MIR (0) exp(cT$^2$) where c is a constant. The measured MIR values at room temperature are usually 2-3 times larger than the data measured at 10 K for all measured frequencies. However, the shapes of the MIR curves are remained. This result shows the potential application of the MI effect for a temperature sensor. The frequency dependence of MIR has shown the typical tendency where the maximum values of MIR are increasing ans also the shapes of MIR curves are getting broader as the measured frequency increases.

  • PDF

A Structural Relationship between Place Attachment and Environmental Factor to Temple Forest Trail in Gyeongju National Park (경주국립공원 사찰숲길에 있어 장소애착과 환경요인의 구조적 관계)

  • Lee, Duk-Jae;Kwon, Tae-Ho
    • Korean Journal of Environment and Ecology
    • /
    • v.26 no.2
    • /
    • pp.283-291
    • /
    • 2012
  • The aim of this study is to explore the structural relationship between recognition to environmental factor and place attachment of the users of temple forest trail in Gyeongju National Park, and to suggest political implications on conservation management of National Park from the viewpoint of landscape attachment. Survey with a structured questionnaire was implemented to visitors to the Bulkuksa, a representative temple in Geyongju National Park. Structural equation model was developed from the analysis of collected data. Results showed that place dependence positively affected place attachment in significance, whereas place identity did not significantly affect place attachment. Place attachment was affected rather by place dependence(path coefficient=0.55). Place attachment positively affected the recognition of environmental factors in significance. Landscape use factors compared to facility use factors were affected rather by place attachment(path coefficient=1.01). This result verified the importance of landscape factors of National Park, and suggested a management plan focused on the landscape conservation of forest trail of traditional temple.

The Study of Dependence on Sportswear and the Effects of Wearing Sportswear (스포츠웨어에 대한 의존성과 착용효과에 관한 연구)

  • Park, Soozin;Ahn, Minyoung;Lee, Yuri
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.39 no.1
    • /
    • pp.77-90
    • /
    • 2015
  • When enjoying sports activities with friends or others, sportswear has symbolic meanings to express and expect self-concept. Sports players sometimes have trouble when they feel embarrassed by their low skills or care about other people too much. Therefore, researchers tried to find out which feature of sports players affects dependence on brand sportswear along with the effect of wearing conspicuous sportswear on wearer when sports players have a conflict based on Solomon's symbolic interactionism. We proposed that role knowledge and attention to social comparison information (ATSCI) influenced people to depend on and use brand sportswear that influences a reflexive evaluation. Finally, we suggested that a changed self-concept would exert influence commitment to sports. A quantitative study was conducted employing an online survey of 121 people by convenient sampling. In this process, Google Docs was to create the online survey and to collect responses by participants. In data processing, via SPSS 21.0 version for Windows, exploratory factor analysis, Cronbach's ${\alpha}$, ANOVA, t-test, discriminant and regression analysis were conducted to study the relationship between variables. The finding provided evidence that low role knowledge and high ATSCI create high dependence on brand sportswear and influence people to buy sportswear. When people bought and wore a brand sportswear, they evaluated themselves as professional sports players who were more committed to sports. This study confirmed that brand sportswear was useful for sport players to change self-evaluation and enjoy sports.

Dependence of Barredness of Late-Type Galaxies on Galaxy Properties and Environment

  • Lee, Gwang-Ho;Park, Chang-Bom;Lee, Myung-Gyoon;Choi, Yun-Young
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.35 no.1
    • /
    • pp.75.2-75.2
    • /
    • 2010
  • We investigate the dependence of occurrence of bar in galaxies on galaxy properties and environment. The environmental conditions considered include the large-scale background density and distance to the nearest neighbor galaxy. We use a volume-limited sample of 33,296 galaxies brighter than $M_r$=-19.5+5logh at $0.02{\leqq}z{\leqq}0.05489$, drawn from the Sloan Digital Sky Survey Data Release 7. We classify the galaxies into early and late types, and identify bars by visual inspection. We find that the fraction of barred galaxies ($f_{bar}$) is 18.2% on average in the case of late-type galaxies, and depends on both u-r color and central velocity dispersion $(\sigma);f_{bar}$ is a monotonically increasing function of u-r color, and has a maximum value at intermediate velocity dispersion (${\sigma}{\simeq}170km\;s^{-1}$). This trend suggests that bars are dominantly hosted by systems having intermediate-mass with no recent interaction or merger history. We also find that $f_{bar}$ does not directly depend on the large-scale background density as its dependence disappears when other physical parameters are fixed. We discover the bar fraction decreases as the separation to the nearest neighbor galaxy becomes smaller than 0.1 times the virial radius of the neighbor regardless of neighbor's morphology. These results imply that it is difficult for bars to be maintained during strong tidal interactions, and that the source for this phenomenon is gravitational and not hydrodynamical.

  • PDF

Stages of Change in Smoking Cessation and Factors Related to Re-smoking after Coronary Artery Bypass Graft Surgery (관상동맥우회술 후 금연변화단계와 관련요인 조사 연구)

  • Choi, Seung-Hee;Song, Kyung-Ja;ChoiKwon, S.-Mi
    • Journal of Korean Academy of Nursing
    • /
    • v.37 no.7
    • /
    • pp.1159-1165
    • /
    • 2007
  • Purpose: The purpose of this study was to investigate the stages of change in smoking cessation after a Coronary Artery Bypass Graft(CABG) and to identify the related factors. Methods: The subjects (n=157) were patients who underwent a CABG in a university hospital from March 1998 to October 2005 and were smokers before the CABG. Data was collected viachart review and a telephone interview, and analyzed with descriptive statistics, $X^2$ test, one-way ANOVA, and Kruskal-Wallis procedure by the SPSS/PC win 12.0 program. Results: The subjects smoked for an average of 34 years (21 cigarettes per day) before surgery. Eleven percent of the subjects were in pre-contemplation, 6.4% in contemplation, 13.5% in preparation, 4.5% in action, and 64.5% in the maintenance stage. Nicotine dependence and self-efficacy were different among the groups with different stages of change in smoking cessation. Nicotine dependence was the lowest (p=0.00) and self-efficacy was the highest (p=0.00) in the maintenance stage. The number of subjects in pre-contemplation and contemplation significantly increased 6 years after surgery(p=0.05). Conclusions: To implement effective smoking cessation interventions for CABG patients, the intervention should be developed to accommodate individual readiness for smoking cessation, especially so for those who had a CABG more than 6 years previously.

Analysis of China's trade dependency on the countries participating in the Belt and Road initiative (일대일로 참여국가에 대한 중국의 무역 의존성 분석과 시사점)

  • Song, Min-Geun
    • Journal of Digital Convergence
    • /
    • v.15 no.9
    • /
    • pp.189-200
    • /
    • 2017
  • The purpose of this study is to identify the characteristics of China's trade relationships with and dependency on the countries participating in the Belt and Road initiative and to present some implications. This study collected annual total imports, exports, and GDP data from the International Monetary Fund (IMF) on 198 countries and the National Bureau of Statistics of China (NBS) on 221 countries from 1995 to 2015. China's imports and exports have expanded considerably from the mid-1990s to the present, and China's dependence on imports and exports with the US and Japan has declined, while its dependence on the Middle East, South Africa, South America, and Southeast Asia has increased. China has a very high level of dependence on imports from and exports to the countries participating in the Belt and Road initiative, and as the Belt and Road project progresses, the mutual trade dependency between China and the other participating countries is expected to strengthen and expand.

Dependence of solar proton events on their associated activities: solar and interplanetary type II radio burst, flare, and CME

  • Park, Jinhye;Youn, Saepoom;Moon, Yong-Jae
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.41 no.1
    • /
    • pp.80.2-81
    • /
    • 2016
  • We investigate the dependence of solar proton events (SPEs) on solar and interplanetary type II bursts associated with solar flares and/or CME-driven shocks. For this we consider NOAA solar proton events from 1997 to 2012 and their associated flare, CME, and type II radio burst data with the following subgroups: metric, decameter-hectometric (DH), and meter-to-kilometric (m-to-km) type II bursts. The primary findings of this study are as follows. First, about half (52%) of the m-to-km type II bursts are associated with SPEs and its occurrence rate is higher than those of DH type II bursts (45%) and metric type II bursts (19%). Second, the SPE occurrence rate strongly depends on flare strength and source longitude, especially for X-class flare associated ones; it is the highest in the central region for metric (46%), DH (54%), and m-to-km (75%) subgroups. Third, the SPE occurrence rate is also dependent on CME linear speed and angular width. The highest rates are found in the m-to-km subgroup associated with CME speed 1500 kms-1: partial halo CME (67%) and halo CME (55%). Fourth, in the relationships between SPE peak fluxes and solar eruption parameters (CME linear speed, flare flux, and longitude), SPE peak flux is mostly dependent on SPE peak flux for all three type II bursts (metric, DH, m-to-km). It is noted that the dependence of SPE peak flux on flare peak flux decreases from metric to m-to-km type II burst.

  • PDF

Alcohol Use Disorder, Stress, Mental Health and Suicide among Seoul Citizens (서울시 지역주민의 알코올장애와 스트레스, 정신건강 및 자살)

  • Sohn, Ae-Ree;Legaspi, Sherme Villasurda;Hong, In-Ok;Kim, Tae-Kyung;Ryu, Eun-Jung;Oh, Gyung-Jae
    • Korean Journal of Health Education and Promotion
    • /
    • v.26 no.4
    • /
    • pp.71-81
    • /
    • 2009
  • Objectives: This study furthers the currents understanding of alcohol use disorders, stress, mental health status and suicide among Seoul citizens. This study is to identify differences according to socio-demographic variables and variables which affect stress, mental status and suicide for developing mental health programs. Methods: The study subjects using cluster-stratified sampling method were 1234 adults over 19 years old from 17 dong, S-Ku in Seoul City. A cross-sectional study with face-to-face interview was used to collect data. A questionnaire measuring socio-demographic variables, Symptom Checklist-90-Revised (SCL-90-R) and psychosocial wellbeing index-short form (PWI-SF) was utilized. Results: Three findings in this study were discussed: (1) The prevalence of problem drinking and alcohol dependence and AUDIT score were significantly higher among male, younger age, and high level of education and income; (2) AUDIT score were related with stress, all 9 symptoms of SCL-R and suicide plan; (3) Problem drinkers were more likely to have 2.5 times of anxiety, 3.0 times of hostility, and 2.4 times psychoticism than non alcohol problem drinkers. Alcohol dependence drinkers were more likely to have 1.9 times of high risk group of stress, 4.1 times of obsessive-compulsive, 4.7 times of anxiety, 5.5 times of hostility, and 2.3 times psychoticism than non alcohol dependence drinkers. Conclusion: The findings suggest that the future intervention of Mental Health programs should be carefully designed and tailored by socio-demographic variables.