• 한국융합학회논문지
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• 제10권5호
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• pp.125-131
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• 2019

본 연구에서는 O2O 마케팅 수단으로서 비콘의 수용에 영향을 미치는 요인의 파악을 시도하였다. 구체적으로 관련 변인들에서 마케팅 커뮤니캐이션 수단으로서 비콘의 수용자와 비수용자 사이에 차이가 있는지 검증하였다. 연구결과 '스마트폰 이용량'과 '브랜드 인식'에서 인지자와 비인지자 사이에 유의미한 차이가 발견되었다. 또한 마케팅 커뮤니케이션 수단으로서 비콘의 수용 예측 변인을 파악하기 위하여 '마케팅 커뮤니케이션 수단으로서 비콘의 수용'을 종속변인으로 로지스틱 회귀분석을 실시하였다. 연구결과 '스마트폰 이용량'과 '브랜드 인식' 모두 마케팅 커뮤니케이션 수단으로서 비콘의 수용에 영향을 미치는 예측변인임이 검증되었다. 본 연구 결과를 TAM에서 주장되는 지각된 유용성과 지각된 사용 용이성 관점에서 분석하였다.

• 응용통계연구
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• 제34권2호
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• pp.153-166
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• 2021

약물유전체학 연구의 주요 목표는 고차원의 유전 변수를 기반으로 개인의 약물 반응성을 예측하는 것이다. 변수의 개수가 많기 때문에 변수의 개수를 줄이기 위해서는 변수 선택이 필요하며, 선택된 변수들은 머신러닝 알고리즘을 사용하여 예측 모델을 구축하는데 사용된다. 본 연구에서는 400명의 뇌전증 환자의 차세대 염기서열 분석 데이터에 로지스틱 회귀, ReliefF, TurF, 랜덤 포레스트, LASSO의 조합과 같은 여러 가지 혼합 변수 선택 방법을 적용하였다. 선택된 변수들에 랜덤포레스트, 그래디언트 부스팅, 서포트벡터머신을 포함한 머신러닝 방법들을 적용했고 스태킹을 통해 앙상블 모형을 구축하였다. 본 연구의 결과는 랜덤포레스트와 ReliefF의 혼합 변수 선택 방법을 이용한 스태킹 모형이 다른 모형보다 더 좋은 성능을 보인다는 것을 보여주었다. 5-폴드 교차 검증을 기반으로 하여 적합한 최적 모형의 평균 검증 정확도는 0.727이고 평균 검증 AUC 값은 0.761로 나타났다. 또한, 동일한 변수를 사용할 때 스태킹 모델이 단일 머신러닝 예측 모델보다 성능이 우수한 것으로 나타났다.

• 지적과 국토정보
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• 제51권2호
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• pp.141-150
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• 2021

미세먼지는 사람의 건강에 많은 영향을 미치는 물질로서 이와 관련하여 다양한 연구가 이루어지고 있다. 미세먼지의 인체 영향으로 인해 서울시 모니터링 네트워크에서 측정된 과거 데이터를 활용하여 미세먼지를 예측하려는 다양한 연구가 진행되고 있다. 본 연구는 2019년 5월 서울시의 미세먼지를 중점으로 진행하였으며, 학습에 사용한 변수는 SO₂, CO, NO₂, O₃와 같은 대기오염물질 데이터를 활용하였다. 예측모델은 Adaboost에 기반하여 구축하였고, 훈련모델은 PM₁₀과 PM_2.5로 구분하였다. 에러 메트릭스를 통한 예측모델의 정확도 평가 결과로 Adaboost가 시도되었다. 대기오염물질은 초미세먼지와 더 높은 상관성을 보이는 것으로 나타났지만, 보다 효과적인 분포등급을 제시하기 위해서는 많은 양의 데이터를 학습하고, PM₁₀과 PM_2.5의 공간분포 등급을 효과적으로 예측하기 위해서 교통량 등의 추가적인 변수를 활용할 필요성이 있다고 판단된다.

• 지역사회간호학회지
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• 제31권3호
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• pp.395-404
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• 2020

Purpose: This study was conducted to develop a predictive model for happiness of students in general high schools. The study was based on the theory of happiness integration and the literature review. Methods: Data were collected using a convenience sample of 231 first and second grade students in five general high schools in D city and K Province. The exogenous variables were optimism as personality factors, parenting attitude, academic stress and friend's support as happiness. The endogenous variables were self-esteem and resilience as mediating variables, and happiness of students in general high schools. Data collection was done from March 14 to March 28, 2019. The AMOS 22.0 and SPSS programs were used to verify the validity of confirmatory factor analysis and hypothesis models. Results: The factors that have the greatest influence on happiness of high school students are self-esteem and resilience. The explanatory power of happiness by these variables was 98.1%. The individual mediating effect and double mediation effect of these variables were found to be significant. Conclusion: As student's optimistic personality, parent's positive parenting attitude, and friend's support improve student's self-esteem and resilience, ultimately positively affecting high school students' happiness, so it is necessary to consider these factors and try to develop a happiness improvement program.

• Computers and Concrete
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• 제19권5호
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• pp.501-507
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• 2017

The predictive utility of a damage model depends heavily on its particular choice of a damage variable, which serves as a macroscopic approximation in describing the underlying micromechanical processes of microdefects. In the case of spatially perfectly randomly distributed microcracks or microvoids in all directions, isotropic damage model is an appropriate choice, and scalar damage variables were widely used for isotropic or one-dimensional phenomenological damage models. The simplicity of a scalar damage representation is indeed very attractive. However, a scalar damage model is of somewhat limited use in practice. In order to entirely characterize the isotropic damage behaviors of damaged materials in multidimensional space, a system theory of isotropic double scalar damage variables, including the expressions of specific damage energy release rate, the coupled constitutive equations corresponding to damage, the conditions of admissibility for two scalar damage effective tensors within the framework of the thermodynamics of irreversible processes, was provided and analyzed in this study. Compared with the former studies, the theoretical formulations of double scalar damage variables in this study are given in the form of matrix, which has many features such as simpleness, directness, convenience and programmable characteristics. It is worth mentioning that the above-mentioned theoretical formulations are only logically reasonable. Owing to the limitations of time, conditions, funds, etc. they should be subject to multifaceted experiments before their innovative significance can be fully verified. The current level of research can be regarded as an exploratory attempt in this field.

• 여성건강간호학회지
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• 제13권2호
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• pp.77-87
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• 2007

Purpose: This study was examined the quality of the sexual life among married women in terms of the factor structure of Sexual Quality of Life(SQOL) and evaluated the predictive value of 11 variables for SQOL. Method: Two hundred and ninety-three married women completed the Korean version SQOL scale with information on age, education, length of marriage, family income, health, sexual knowledge, coital frequency, harmony with family members, levels of affection, and general and sexual communication. Data were analysed with principal components and regression analyses. Result: The SQOL scale had two clearly defined factors, Negative Quality of Sexual Life and Positive Quality of Sexual Life, on which all scale items were significantly loaded, accounting for 54.3% of the total variance. Independent regression analysis showed all variables except education to be significant predictors of SQOL with interpersonal variables (general and sexual communication, affection and harmony with family members) being the most powerful predictors. However when the 11 variables were combined together in stepwise analysis, only 6 variables (general communication, age, affection, coital frequency, sexual knowledge and health) were significant, accounting for 39% of the total variance. Conclusion: The Korean version SQOL scale is a good measure to tackle SQOL in married women. To enhance SQOL, strengthening interpersonal interaction focusing on general/sexual communication, affection and harmony with family members seems to be more important than sexual activities and personal characteristics.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6477-6480
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• 2015

Purpose: Given the importance of sun protection in the prevention of skin cancer, this study was designed to determine predictors of sun-protective practices among a sample of Iranian female college students based on protection motivation theory (PMT) variables. Materials and Methods: In this cross-sectional study, a total of 201 female college students in Iran University of Medical Sciences were selected. Demographic and PMT variables were assessed with a 67-item questionnaire. Multiple linear regression was used to identify demographic and PMT variables that were associated with sun-protective practices and intention. Results: one percent of participants always wore a hat with a brim, 3.5% gloves and 15.9% sunglasses while outdoors. Only 10.9% regularly had their skin checked by a doctor. Perceived rewards, response efficacy, fear, self-efficacy and marital status were the five variables which could predict 39% variance of participants intention to perform sun-protective practices. Also, intention and response cost explained 31% of the variance of sun-protective practices. Conclusions: These predictive variables may be used to develop theory-based education interventions to prevent skin cancer among college students.

• Clinical and Experimental Pediatrics
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• 제56권12호
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• pp.534-539
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• 2013

Purpose: Electroencephalography (EEG) is frequently ordered for patients with febrile seizures despite its unclear diagnostic value. We evaluated the prevalence of abnormal EEGs, the association between clinical findings and abnormal EEGs, and the predictive value of EEG for the recurrence of febrile seizures Methods: Data were collected on 230 children who were treated for febrile seizures at Kyung Hee University Medical Center from 2005 to 2009. EEGs were recorded after 1-2 days of hospitalization when children became afebrile. EEG patterns were categorized as normal, epileptiform, or nonspecific relative to abnormalities. The patients' medical records were reviewed, and telephone interviews with the families of the children were conducted to inquire about seizure recurrence. The relationships between clinical variables, including seizure recurrence, and EEG abnormalities were evaluated. Results: Of the 131 children included, 103 had simple and 28 had complex febrile seizures. EEG abnormalities were found in 41 children (31%). EEG abnormalities were more common in children with complex than simple febrile seizures (43% vs. 28%), but the difference was not statistically significant. Logistical regression analysis showed that having multiple seizures in a 24-hour period was significantly predictive of abnormal EEG (odds ratio, 2.98; 95% confidence interval, 1.0 to 88; P =0.048). The frequency of recurrence did not differ significantly in the normal (31%) and abnormal (23%) EEG groups. Conclusion: Multiple seizures within 24 hours were predictive of abnormal EEG in children with febrile seizures. Abnormal EEG was not predictive of febrile seizure recurrence.

• Journal of Korean Neurosurgical Society
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• 제42권2호
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• pp.92-96
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• 2007

Objective : The authors have speculated that metastatic brain lesions from renal cell carcinoma (RCC) show diverse radiological patterns and tumor responses after Gamma knife surgery (GKS), and have hypothesized that these can be predicted from tumor radiological characteristics. The goal of the current study was to identify the radiological characteristics of RCC brain metastases and the predictors of initial radiosurgical response after GKS. Methods : A retrospective analysis was performed on 48 lesions in 18 patients with RCC brain metastasis treated by GKS. The radiological characteristics of these lesions in magnetic resonance images (MRI) were classified into 3 categories according to enhancement patterns in T1-weighted images and signal intensity characteristics in T2-weighted images. Responses to GKS were analyzed according to these categories, and in addition, other potential predictive factors were also evaluated. Results : MRI findings in the three categories were diverse, though numbers of the lesion were comparable. At 2-month MRI follow-ups after GKS, response rate was 54% and the local tumor control rate 83%. T2 signal intensity was found to be the principal predictive factor of response to GKS, namely negative predictive factor. Other variables such as age, sex, tumor volume, dose, duration from initial diagnosis to GKS, and previous systemic therapies failed to show significant relationships with treatment response by multivariate analysis. Conclusion : Careful evaluation of the radiological characteristics of brain metastases from RCC is important prior to GKS because MRI heterogeneity has predictive value in terms of determining initial tumor response.

• Radiation Oncology Journal
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• 제35권2호
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• pp.163-171
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• 2017

Purpose: Although stereotactic ablative body radiotherapy (SABR) is widely used therapeutic technique, predictive factors of radiation pneumonitis (RP) after SABR remain undefined. We aimed to investigate the predictive factors affecting RP in patients with primary or metastatic lung tumors who received SABR. Materials and Methods: From 2012 to 2015, we reviewed 59 patients with 72 primary or metastatic lung tumors treated with SABR, and performed analyses of clinical and dosimetric variables related to symptomatic RP. SABR was delivered as 45-60 Gy in 3-4 fractions, which were over 100 Gy in BED when the ${\alpha}/{\beta}$ value was assumed to be 10. Tumor volume and other various dose volume factors were analyzed using median value as a cutoff value. RP was graded per the Common Terminology Criteria for Adverse Events v4.03. Results: At the median follow-up period of 11 months, symptomatic RP was observed in 13 lesions (12 patients, 18.1%), including grade 2 RP in 11 lesions and grade 3 in 2 lesions. Patients with planning target volume (PTV) of ${\leq}14.35mL$ had significantly lower rates of symptomatic RP when compared to others (8.6% vs. 27%; p = 0.048). Rates of symptomatic RP in patients with internal gross tumor volume (iGTV) >4.21 mL were higher than with ${\leq}4.21mL$ (29.7% vs. 6.1%; p = 0.017). Conclusions: The incidence of symptomatic RP following treatment with SABR was acceptable with grade 2 RP being observed in most patients. iGTV over 4.21 mL and PTV of over 14.35 mL were significant predictive factors related to symptomatic RP.