• 제목/요약/키워드: BIAS

검색결과 6,556건 처리시간 0.032초

외측상과염의 도침 치료에 대한 체계적 문헌고찰 및 메타분석 (Effect of Acupotomy Treatment for Lateral Epicondylitis: A Systematic Review and Meta-Analysis)

  • 최종찬;지민준;서경준;권도영;양재은;구지향;이은정;오민석
    • 한방재활의학과학회지
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    • 제34권2호
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    • pp.101-134
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    • 2024
  • Objectives The purpose of this study is to observe the effectiveness of acupotomy treatment for lateral epicondylitis by comparing it with various control groups. Methods We searched 11 domestic and international databases for systematic reviews and meta-analysis. The subjects were studies published from January 1, 2017 to September 1, 2023, and only randomised controlled trials were included. Results 208 studies were searched, of which 21 studies were finally selected. Among the studies published after 2017, the largest number of studies was published in 2019. The average number of participants per study was 72.28±20.26 and the average age was in the 40s. The most frequent intervention in the study was acupotomy alone, and the treatment most often mentioned as a control group was local nerve block. The most used evaluation tool is efficiency. Acupotomy+manipulation had statistically better effect than that of local nerve block in terms of pain (standard mean difference -1.87, 95% confidence interval, -2.18 to -1.57, p<0.00001) and elbow joint function (standard mean difference 2.25, 95% confidence interval, 1.65 to 2.86, p<0.00001). Conclusions As a result of the meta-analysis, the effect of acupotomy added manual therapy treatment was statistically significant compared to the local nerve block frequently used for lateral epicondylitis. Based on these results, it appears that more research on combination treatments other than acupotomy treatment will be needed. Also, it appears that more large-scale randomized controlled studies that strictly adhere to the standards for reporting interventions in controlled trials of acupuncture, risk of bias 2 criteria will be needed.

Agreement and Reliability between Clinically Available Software Programs in Measuring Volumes and Normative Percentiles of Segmented Brain Regions

  • Huijin Song;Seun Ah Lee;Sang Won Jo;Suk-Ki Chang;Yunji Lim;Yeong Seo Yoo;Jae Ho Kim;Seung Hong Choi;Chul-Ho Sohn
    • Korean Journal of Radiology
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    • 제23권10호
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    • pp.959-975
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    • 2022
  • Objective: To investigate the agreement and reliability of estimating the volumes and normative percentiles (N%) of segmented brain regions among NeuroQuant (NQ), DeepBrain (DB), and FreeSurfer (FS) software programs, focusing on the comparison between NQ and DB. Materials and Methods: Three-dimensional T1-weighted images of 145 participants (48 healthy participants, 50 patients with mild cognitive impairment, and 47 patients with Alzheimer's disease) from a single medical center (SMC) dataset and 130 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset were included in this retrospective study. All images were analyzed with DB, NQ, and FS software to obtain volume estimates and N% of various segmented brain regions. We used Bland-Altman analysis, repeated measures ANOVA, reproducibility coefficient, effect size, and intraclass correlation coefficient (ICC) to evaluate inter-method agreement and reliability. Results: Among the three software programs, the Bland-Altman plot showed a substantial bias, the ICC showed a broad range of reliability (0.004-0.97), and repeated-measures ANOVA revealed significant mean volume differences in all brain regions. Similarly, the volume differences of the three software programs had large effect sizes in most regions (0.73-5.51). The effect size was largest in the pallidum in both datasets and smallest in the thalamus and cerebral white matter in the SMC and ADNI datasets, respectively. N% of NQ and DB showed an unacceptably broad Bland-Altman limit of agreement in all brain regions and a very wide range of ICC values (-0.142-0.844) in most brain regions. Conclusion: NQ and DB showed significant differences in the measured volume and N%, with limited agreement and reliability for most brain regions. Therefore, users should be aware of the lack of interchangeability between these software programs when they are applied in clinical practice.

Quality of Radiomics Research on Brain Metastasis: A Roadmap to Promote Clinical Translation

  • Chae Jung Park;Yae Won Park;Sung Soo Ahn;Dain Kim;Eui Hyun Kim;Seok-Gu Kang;Jong Hee Chang;Se Hoon Kim;Seung-Koo Lee
    • Korean Journal of Radiology
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    • 제23권1호
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    • pp.77-88
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    • 2022
  • Objective: Our study aimed to evaluate the quality of radiomics studies on brain metastases based on the radiomics quality score (RQS), Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) checklist, and the Image Biomarker Standardization Initiative (IBSI) guidelines. Materials and Methods: PubMed MEDLINE, and EMBASE were searched for articles on radiomics for evaluating brain metastases, published until February 2021. Of the 572 articles, 29 relevant original research articles were included and evaluated according to the RQS, TRIPOD checklist, and IBSI guidelines. Results: External validation was performed in only three studies (10.3%). The median RQS was 3.0 (range, -6 to 12), with a low basic adherence rate of 50.0%. The adherence rate was low in comparison to the "gold standard" (10.3%), stating the potential clinical utility (10.3%), performing the cut-off analysis (3.4%), reporting calibration statistics (6.9%), and providing open science and data (3.4%). None of the studies involved test-retest or phantom studies, prospective studies, or cost-effectiveness analyses. The overall rate of adherence to the TRIPOD checklist was 60.3% and low for reporting title (3.4%), blind assessment of outcome (0%), description of the handling of missing data (0%), and presentation of the full prediction model (0%). The majority of studies lacked pre-processing steps, with bias-field correction, isovoxel resampling, skull stripping, and gray-level discretization performed in only six (20.7%), nine (31.0%), four (3.8%), and four (13.8%) studies, respectively. Conclusion: The overall scientific and reporting quality of radiomics studies on brain metastases published during the study period was insufficient. Radiomics studies should adhere to the RQS, TRIPOD, and IBSI guidelines to facilitate the translation of radiomics into the clinical field.

정보보호 의사결정에서 정보보호 침해사고 발생가능성의 심리적 거리감과 상대적 낙관성의 역할 (The Role of Psychological Distance and Relative Optimism in Information Security Decision Making)

  • 김종기;김지윤
    • 경영정보학연구
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    • 제20권3호
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    • pp.51-71
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    • 2018
  • 많은 정보보호 분야 연구들은 인식을 높여야 할 필요성을 밝히고 있다. 그러나 정보보호에 대한 인식이 상당한 수준으로 높아졌음에도 실제 보호행동은 최근까지 그에 미치지 못하고 있다. 이에 인식수준과는 별개로 정보보호 의사결정에 심리적 요인이 작용할 것으로 가정하고 정보보호에 대한 인식에 차이가 없는 실험상황에서 심리적 거리감과 낙관편향에 따른 차이를 확인하고 정보보호 행동에 대한 영향을 확인하고자 하였다. 연구결과 모바일 기기 사용자의 확률적 거리감에 따라 정보보호 위험의 지각에 차이가 있었으며, 사회적 거리감에 따라 상대적 낙관성의 정도에 차이가 있었다. 이를 바탕으로 상대적 낙관성을 개념화하고 정보보호 행동의도와의 관계를 분석한 결과 자신과 가까운 사람과 비교해 더 낙관적이라 생각했을 때 정보보호 위험의 수준을 낮게 평가하고 확률적 거리감에 따라 영향력이 달라짐을 확인했다. 본 연구는 방법론적 측면에서 의미 있는 시도를 하였고, 정보보호와 관련한 행동에 있어 심리적 요인을 고려함으로써 실질적 위험지각에 영향을 미치는 상대적 낙관성의 범위를 좁혔다는 데 의의가 있다. 정보보호를 위한 의사결정 과정에 다각도로 접근할 필요성을 실증적으로 규명함으로써 궁극적으로 정보기술 사용자의 정보보호 수준 향상과 정보자산의 보호에 기여할 것으로 기대한다.

Simultaneous Estimation of the Fat Fraction and R2* Via T2*-Corrected 6-Echo Dixon Volumetric Interpolated Breath-hold Examination Imaging for Osteopenia and Osteoporosis Detection: Correlations with Sex, Age, and Menopause

  • Donghyun Kim;Sung Kwan Kim;Sun Joo Lee;Hye Jung Choo;Jung Won Park;Kun Yung Kim
    • Korean Journal of Radiology
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    • 제20권6호
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    • pp.916-930
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    • 2019
  • Objective: To investigate the relationships of T2*-corrected 6-echo Dixon volumetric interpolated breath-hold examination (VIBE) imaging-based fat fraction (FF) and R2* values with bone mineral density (BMD); determine their associations with sex, age, and menopause; and evaluate the diagnostic performance of the FF and R2* for predicting osteopenia and osteoporosis. Materials and Methods: This study included 153 subjects who had undergone magnetic resonance (MR) imaging, including MR spectroscopy (MRS) and T2*-corrected 6-echo Dixon VIBE imaging. The FF and R2* were measured at the L4 vertebra. The male and female groups were divided into two subgroups according to age or menopause. Lin's concordance and Pearson's correlation coefficients, Bland-Altman 95% limits of agreement, and the area under the curve (AUC) were calculated. Results: The correlation between the spectroscopic and 6-echo Dixon VIBE imaging-based FF values was statistically significant for both readers (pc = 0.940 [reader 1], 0.908 [reader 2]; both p < 0.001). A small measurement bias was observed for the MRS-based FF for both readers (mean difference = -0.3% [reader 1], 0.1% [reader 2]). We found a moderate negative correlation between BMD and the FF (r = -0.411 [reader 1], -0.436 [reader 2]; both p <0.001) with younger men and premenopausal women showing higher correlations. R2* and BMD were more significantly correlated in women than in men, and the highest correlation was observed in postmenopausal women (r = 0.626 [reader 1], 0.644 [reader 2]; both p < 0.001). For predicting osteopenia and osteoporosis, the FF had a higher AUC in men and R2* had a higher AUC in women. The AUC for predicting osteoporosis was highest with a combination of the FF and R2* in postmenopausal women (AUC = 0.872 [reader 1], 0.867 [reader 2]; both p < 0.001). Conclusion: The FF and R2* measured using T2*-corrected 6-echo Dixon VIBE imaging can serve as predictors of osteopenia and osteoporosis. R2* might be useful for predicting osteoporosis, especially in postmenopausal women.

Allometric equation for estimating aboveground biomass of Acacia-Commiphora forest, southern Ethiopia

  • Wondimagegn Amanuel;Chala Tadesse;Moges Molla;Desalegn Getinet;Zenebe Mekonnen
    • Journal of Ecology and Environment
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    • 제48권2호
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    • pp.196-206
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    • 2024
  • Background: Most of the biomass equations were developed using sample trees collected mainly from pan-tropical and tropical regions that may over- or underestimate biomass. Site-specific models would improve the accuracy of the biomass estimates and enhance the country's measurement, reporting, and verification activities. The aim of the study is to develop site-specific biomass estimation models and validate and evaluate the existing generic models developed for pan-tropical forest and newly developed allometric models. Total of 140 trees was harvested from each diameter class biomass model development. Data was analyzed using SAS procedures. All relevant statistical tests (normality, multicollinearity, and heteroscedasticity) were performed. Data was transformed to logarithmic functions and multiple linear regression techniques were used to develop model to estimate aboveground biomass (AGB). The root mean square error (RMSE) was used for measuring model bias, precision, and accuracy. The coefficient of determination (R2 and adjusted [adj]-R2), the Akaike Information Criterion (AIC) and the Schwarz Bayesian information Criterion was employed to select most appropriate models. Results: For the general total AGB models, adj-R2 ranged from 0.71 to 0.85, and model 9 with diameter at stump height at 10 cm (DSH10), ρ and crown width (CW) as predictor variables, performed best according to RMSE and AIC. For the merchantable stem models, adj-R2 varied from 0.73 to 0.82, and model 8) with combination of ρ, diameter at breast height and height (H), CW and DSH10 as predictor variables, was best in terms of RMSE and AIC. The results showed that a best-fit model for above-ground biomass of tree components was developed. AGBStem = exp {-1.8296 + 0.4814 natural logarithm (Ln) (ρD2H) + 0.1751 Ln (CW) + 0.4059 Ln (DSH30)} AGBBranch = exp {-131.6 + 15.0013 Ln (ρD2H) + 13.176 Ln (CW) + 21.8506 Ln (DSH30)} AGBFoliage = exp {-0.9496 + 0.5282 Ln (DSH30) + 2.3492 Ln (ρ) + 0.4286 Ln (CW)} AGBTotal = exp {-1.8245 + 1.4358 Ln (DSH30) + 1.9921 Ln (ρ) + 0.6154 Ln (CW)} Conclusions: The results demonstrated that the development of local models derived from an appropriate sample of representative species can greatly improve the estimation of total AGB.

DNA 길이와 혼합 종 개수 예측을 위한 합성곱 신경망 (Convolution Neural Network for Prediction of DNA Length and Number of Species)

  • 승희;김예원;이효민
    • Korean Chemical Engineering Research
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    • 제62권3호
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    • pp.274-280
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    • 2024
  • 기계학습법의 신경망 기술을 이용한 자료분석은 질병 유전자 탐색 및 진단, 신약 개발, 약인성 간 손상 예측 등과 같은 다양한 분야에서 활용되고 있다. 질병 특징 발견을 위한 자료분석은 DNA 정보를 기반으로 이루어질 수 있다. 본 연구에서는 DNA의 분자 정보 중 DNA의 길이와 용액 내 DNA의 길이별 종 개수를 예측하는 신경망을 개발하였다. 겔 전기영동을 통한 기존 방법론의 시간 소요 한계점을 해결하고자, 미세유체역학적 농축 장치의 동역학 자료를 분석 대상으로 하여 실험 분석 과정 중의 시간 소요 문제점을 해결하였다. 동역학 자료를 공간시간 지도로 재구성하여 학습 및 예측에 필요한 계산용량을 낮추었으며, 공간시간 지도에 대한 분석 정확도를 높이기 위해 합성곱 신경망을 활용하였다. 그 결과, 단일 변수 회귀로써의 단일 DNA 길이 예측과 복합 변수 회귀로써의 다종 DNA 길이의 동시 예측 및 이진 분류로써의 DNA 혼합 종 개수 예측을 성공적으로 수행하였다. 추가적으로, 예측 과정 중 발생할 수 있는 예측 편향을 학습 자료 구성 방식을 통한 해결책을 제시하였다. 본 연구를 활용한다면, 광학 측정 자료를 이용하는 액체생검 기반의 세포유리 DNA 분석 및 암 진단 등의 의학 자료 분석을 효과적으로 수행할 수 있을 것이다.

ChatGPT에 대한 대학생의 인식에 관한 연구 (A Study on College Students' Perceptions of ChatGPT)

  • 이정욱;김희라;신혜원
    • 한국가정과교육학회지
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    • 제35권4호
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    • pp.1-12
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    • 2023
  • ChatGPT의 교육적 활용에 대한 관심이 증가하고 있는 시점에서 대학생을 대상으로 ChatGPT에 대한 인식을 알아보는 것은 필요하다. D대학교 2023년도 1학기 '가정생활과 문화', '패션과 미술관', '영화로 만나는 패션' 수강생을 대상으로 인터넷과 대화형 인공지능 사용실태 그리고 수업에서 ChatGPT를 활용한 후 그에 대한 인식을 설문지, 비교분석 보고서, 성찰일지로 살펴보았다. 대학생은 수업을 위한 정보는 주로 인터넷 검색과 논문에서 주로 얻고 있었으며 대화형 인공지능을 이용하는 경우는 아직 미비함을 알 수 있었다. ChatGPT는 대부분 2023년 1학기에 처음 사용하였으며 대화형 인공지능 중 주로 ChatGPT를 사용하였다. ChatGPT는 정보의 정확성과 신뢰도면에서는 조금 부족하나 쉽고 빠르게 상호작용을 하면서 정보를 찾을 수 있어 편리하며 만족도가 높아 앞으로 ChatGPT를 보다 적극적으로 활용할 용의가 있었다. ChatGPT가 교육에 미치는 영향에 대해 학생들은 자기 주도적이며 질문을 통한 문제해결 태도와 정보에 대한 검증과정을 위해 모둠별 토의·토론을 통해 확인하는 협동수업의 과정을 학습자 스스로가 설정하는 것이 긍정적이라고 하였다. 그러나 표절과 저작권, 데이터 편향성, 최신 데이터 학습부족, 정확하지 않거나 잘못된 정보를 생성하는 등의 신뢰를 저하시키는 문제점이 있다는 것을 인식하였으며 이에 대한 보완이 필요하다고 하였다.

구름미세물리 모수화 방안 내 빗방울의 특성을 정의하는 매개변수가 한반도 여름철 강수 모의에 미치는 영향 (Effects of Parameters Defining the Characteristics of Raindrops in the Cloud Microphysics Parameterization on the Simulated Summer Precipitation over the Korean Peninsula)

  • 김기병;김권일;이규원;임교선
    • 대기
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    • 제34권3호
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    • pp.305-317
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    • 2024
  • The study examines the effects of parameters that define the characteristics of raindrops on the simulated precipitation during the summer season over Korea using the Weather Research and Forecasting (WRF) Double-Moment 6-class (WDM6) cloud microphysics scheme. Prescribed parameters, defining the characteristics of hydrometeors in the WDM6 scheme such as aR, bR, and fR in the fall velocity (VR) - diameter (DR) relationship and shape parameter (𝜇R) in the number concentration (NR) - DR relationship, presents different values compared to the observed data from Two-Dimensional Video Disdrometer (2DVD) at Boseong standard meteorological observatory during 2018~2019. Three experiments were designed for the heavy rainfall event on August 8, 2022 using WRF version 4.3. These include the control (CNTL) experiment with original parameters in the WDM6 scheme; the MUR experiment, adopting the 50th percentile observation value for 𝜇R; and the MEDI experiment, which uses the same 𝜇R as MUR, but also includes fitted values for aR, bR, and fR from the 50th percentile of the observed VR - DR relationship. Both sensitivity experiments show improved precipitation simulation compared to the CNTL by reducing the bias and increasing the probability of detection and equitable threat scores. In these experiments, the raindrop mixing ratio increases and its number concentration decreases in the lower atmosphere. The microphysics budget analysis shows that the increase in the rain mixing ratio is due to enhanced source processes such as graupel melting, vapor condensation, and accretion between cloud water and rain. Our study also emphasizes that applying the solely observed 𝜇R produces more positive impact in the precipitation simulation.

가상 커뮤니티에서 사회적 자본과 정체성이 지식기여에 미치는 역할: 실증적 분석 (The Role of Social Capital and Identity in Knowledge Contribution in Virtual Communities: An Empirical Investigation)

  • 신호경;김경규;이은곤
    • Asia pacific journal of information systems
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    • 제22권3호
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    • pp.53-74
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    • 2012
  • A challenge in fostering virtual communities is the continuous supply of knowledge, namely members' willingness to contribute knowledge to their communities. Previous research argues that giving away knowledge eventually causes the possessors of that knowledge to lose their unique value to others, benefiting all except the contributor. Furthermore, communication within virtual communities involves a large number of participants with different social backgrounds and perspectives. The establishment of mutual understanding to comprehend conversations and foster knowledge contribution in virtual communities is inevitably more difficult than face-to-face communication in a small group. In spite of these arguments, evidence suggests that individuals in virtual communities do engage in social behaviors such as knowledge contribution. It is important to understand why individuals provide their valuable knowledge to other community members without a guarantee of returns. In virtual communities, knowledge is inherently rooted in individual members' experiences and expertise. This personal nature of knowledge requires social interactions between virtual community members for knowledge transfer. This study employs the social capital theory in order to account for interpersonal relationship factors and identity theory for individual and group factors that may affect knowledge contribution. First, social capital is the relationship capital which is embedded within the relationships among the participants in a network and available for use when it is needed. Social capital is a productive resource, facilitating individuals' actions for attainment. Nahapiet and Ghoshal (1997) identify three dimensions of social capital and explain theoretically how these dimensions affect the exchange of knowledge. Thus, social capital would be relevant to knowledge contribution in virtual communities. Second, existing research has addressed the importance of identity in facilitating knowledge contribution in a virtual context. Identity in virtual communities has been described as playing a vital role in the establishment of personal reputations and in the recognition of others. For instance, reputation systems that rate participants in terms of the quality of their contributions provide a readily available inventory of experts to knowledge seekers. Despite the growing interest in identities, however, there is little empirical research about how identities in the communities influence knowledge contribution. Therefore, the goal of this study is to better understand knowledge contribution by examining the roles of social capital and identity in virtual communities. Based on a theoretical framework of social capital and identity theory, we develop and test a theoretical model and evaluate our hypotheses. Specifically, we propose three variables such as cohesiveness, reciprocity, and commitment, referring to the social capital theory, as antecedents of knowledge contribution in virtual communities. We further posit that members with a strong identity (self-presentation and group identification) contribute more knowledge to virtual communities. We conducted a field study in order to validate our research model. We collected data from 192 members of virtual communities and used the PLS method to analyse the data. The tests of the measurement model confirm that our data set has appropriate discriminant and convergent validity. The results of testing the structural model show that cohesion, reciprocity, and self-presentation significantly influence knowledge contribution, while commitment and group identification do not significantly influence knowledge contribution. Our findings on cohesion and reciprocity are consistent with the previous literature. Contrary to our expectations, commitment did not significantly affect knowledge contribution in virtual communities. This result may be due to the fact that knowledge contribution was voluntary in the virtual communities in our sample. Another plausible explanation for this result may be the self-selection bias for the survey respondents, who are more likely to contribute their knowledge to virtual communities. The relationship between self-presentation and knowledge contribution was found to be significant in virtual communities, supporting the results of prior literature. Group identification did not significantly affect knowledge contribution in this study, inconsistent with the wealth of research that identifies group identification as an important factor for knowledge sharing. This conflicting result calls for future research that examines the role of group identification in knowledge contribution in virtual communities. This study makes a contribution to theory development in the area of knowledge management in general and virtual communities in particular. For practice, the results of this study identify the circumstances under which individual factors would be effective for motivating knowledge contribution to virtual communities.

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