• Journal of the Korean Statistical Society
• /
• 제27권1호
• /
• pp.67-90
• /
• 1998

In this paper we analytically study model misspecification that arises in regression analysis of nonstationary seasonal time series. We assume the underlying data generating process is a seasonally or a regularly and seasonally integrated process. We first study consequences of totally misspecified cases where seasonal indicator variables, a linear time trend, or another statistically independent seasonally integrated process are used as predictor variables in order to model the nonstationary seasonal behavior of the dependent variable. Then we study consequences of partially misspecified cases where the dependent variable and a predictor variable are cointegrated at some, but not all of the frequencies corresponding to the nonstationary roots.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권7호
• /
• pp.2667-2682
• /
• 2015

Due to the wide application of face recognition (FR) in information security, surveillance, access control and others, it has received significantly increased attention from both the academic and industrial communities during the past several decades. However, partial face occlusion is one of the most challenging problems in face recognition issue. In this paper, a novel method based on linear regression-based classification (LRC) algorithm is proposed to address this problem. After all images are downsampled and divided into several blocks, we exploit the evaluator of each block to determine the clear blocks of the test face image by using linear regression technique. Then, the remained uncontaminated blocks are utilized to partial occluded face recognition issue. Furthermore, an improved Distance-based Evidence Fusion approach is proposed to decide in favor of the class with average value of corresponding minimum distance. Since this occlusion removing process uses a simple linear regression approach, the completely computational cost approximately equals to LRC and much lower than sparse representation-based classification (SRC) and extended-SRC (eSRC). Based on the experimental results on both AR face database and extended Yale B face database, it demonstrates the effectiveness of the proposed method on issue of partial occluded face recognition and the performance is satisfactory. Through the comparison with the conventional methods (eigenface+NN, fisherfaces+NN) and the state-of-the-art methods (LRC, SRC and eSRC), the proposed method shows better performance and robustness.

• 아동학회지
• /
• 제35권1호
• /
• pp.119-133
• /
• 2014

The purpose of this study is to examine the effects of time perspective, self-control and cellular phone addiction on academic procrastination, and to cellular phone addiction has any mediating effects in relation to the effects of adolescents' time perspective and self-control on academic procrastination. For this study, a survey was conducted with total 651 students in middle and high schools. Those who omitted responses or answered in ways which were otherwise invalid were excluded and finally, questionnaires responded to by 558 students were analyzed. Employing SPSS Win 12.0, average value, standard deviation, frequency analysis, Pearson's correlation analysis, stepwise multiple regression analysis, and simple linear regression analysis were used for the purposes of statistical analysis. In conclusion, first, explanations were made in order of future-oriented time perspective which is subordinate domain of view of time perspective, self-control, and cellular phone addiction. Second, it was found that cellular phone addiction has partially mediating effect on the relationships between future-oriented time perspective which is a subordinate area of adolescents' time perspective, and academic procrastination. Third, it was found that cellular phone addiction has partially mediating effect on the relationships between adolescents' self-control and academic procrastination.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권2호
• /
• pp.1017-1023
• /
• 2021

This research aims to determine the effect of customers' threat emotion and price on the decision to purchase a certain smartphone product. This study uses a quantitative method with a type of descriptive and causal research. It employs non-probability sampling with purposive sampling, with 385 respondents to answer the questionnaires. Data analysis techniques used descriptive analysis and multiple linear regression analysis. Based on the results of descriptive analysis of emotion, price and purchasing decisions are in sync with each other. The results of multiple linear regression analysis techniques indicate the threat emotion and brand trust are influential against the positive decision to purchase smartphone products. The magnitude of the influence of emotions and price have simultaneous effect on purchasing decisions and other decision variables, which are not included in this study, also play minor role in determining purchase intention, such as product quality, brand image and others. Partially, threat emotion and brand trust have a positive effect toward purchasing decisions. The magnitude of the highest influence was the one of price, then followed by emotional threats. The findings of this study suggest that psychological and behavioral effects also play important roles in determining customers' purchase decision.

• 대한치과기공학회지
• /
• 제45권4호
• /
• pp.102-110
• /
• 2023

Purpose: This study aims to examine the influence of personality types on recovery resilience and college life adjustment among dental technology students. Methods: The study recruited 165 students in colleges in some areas using convenience sampling. Data were processed through reliability analysis, frequency analysis, descriptive statistics, and correlation analysis. Moreover, linear regression analysis was performed to confirm the influence. Results: The results confirmed that the motivation for selecting a department exerted an effect on adaptation to college life and satisfaction with majors (p<0.05). Additionally, the finding indicated that personality type partially influenced resilience and adaptation to college life among dental technology students (p<0.05). Finally, the results of regression analysis on adaptation to college life found that resilience and satisfaction with majors were significant predictors of adaptation to college life (p<0.05). Conclusion: To improve adaptation to college life, increasing resilience and satisfaction with majors is necessary.

• 대한산업공학회지
• /
• 제28권3호
• /
• pp.331-343
• /
• 2002

This paper proposes a fuzzy rule-based model as a means to build usability models between emotional satisfaction and design variables of consumer products. Based on a subtractive clustering algorithm, this model obtains partially overlapping rules from existing data and builds multiple local models each of which has a form of a linear regression equation. The best subset procedure and cross validation technique are used to select appropriate input variables. The proposed technique was applied to the modeling of luxuriousness, balance, and attractiveness of office chairs. For comparison, regression models were built on the same data in two different ways; one using only potentially important variables selected by the design experts, and the other using all the design variables available. The results showed that the fuzzy rule-based model had a great benefit in terms of the number of variables included in the model. They also turned out to be adequate for predicting the usability of a new product. Better yet, the information on the product classes and their satisfaction levels can be obtained by interpreting the rules. The models, when combined with the information from the regression models, are expected to help the designers gain valuable insights in designing a new product.

• Human Ecology Research
• /
• 제54권1호
• /
• pp.45-56
• /
• 2016

This study investigates: (1) children's proactive aggression according to age and the emotional condition of the counterpart child, (2) if children's intention attribution, emotional attribution (victim and perpetrator) and language ability influences proactive aggression according to age and the emotional condition of the counterpart child. The subjects were 68 3-year-old and 70 5-year-old children. Each child was individually interviewed with picture cards. Collected data were coded and analyzed in SPSS with frequencies, percentiles, means, standard deviations, repeated measures analysis of variance (ANOVA), t -tests, Pearson correlations and multiple linear regression. The results showed that 3-year-old children showed more proactive aggression and physical aggression than 5-year-old children. They showed more proactive aggression when counterpart child was in a happy condition than in a fear condition. Intention attribution, emotional attribution, and language ability partially affected a children's proactive aggression according to age and the emotional condition of the counterpart child. This study has practical implications for teachers in regards to children's proactive aggressive behavior at child care centers. Teachers use specific to develop advantages as the basis for developing aggression prevention programs that consider emotional and cognitive factors.

• 한국물환경학회지
• /
• 제24권2호
• /
• pp.156-163
• /
• 2008

This study was to introduce a methodology of ecological health assessment for efficient management and to provide some diagnostic results of the survey. We evaluated ecological health assessment at five sampling locations of Sikjang Mountainous Stream using the index of biological integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) during May - October 2006. The health condition, based on the IBI model, averaged 32 and varied from 27 to 37 depending on the sampling sites. Thus, the stream health was judged as "good" to "fair" conditions. IBI values showed slight differences between upstream and downstream sites. Whereas, QHEI values varied from 75 (fair condition) to 196 (excellent condition) and QHEI at St. 4~5, indicating the downstream reach had significantly lower than the headwater site (St.1). Regression analyses also showed that QHEI values had a linear decrease from the headwater to downstream. This result indicated that habitat quality was rapidly degradated by human influence. Overall, data of IBI and QHEI suggested that the stream health was maintained well in the present but the habitat and biological quality were partially degradated in the downstream. So, the human interference should be minimized to protect the downstream environment.

• 아동학회지
• /
• 제32권6호
• /
• pp.1-13
• /
• 2011

The main purpose of this study was to examine the mediating effects of the hours spent on book-reading on the relationship between academic achievement and the Key Competency of Acting Autonomously. This study utilized data from the 'Korean Assessment of the Key Competencies of Youth in 2009', which was conducted by the National Youth Policy Institute. The participants were 2,781 elementary school students, 2,770 middle school students and 3,599 high school students who were selected from 12 areas of Korea. The data was analyzed by means of Pearson's correlation coefficients and also through linear regression analysis. The results indicated that 1) academic achievement and the hours spent in book-reading was positively correlated to the competency of acting autonomously, 2) the effect of academic achievement on the competency of acting autonomously was partially mediated by the hours spent in book-reading, 3) and the mediating effect was the most influential when it came to elementary students, followed next by middle school and then finally high school students.

• 물과 미래
• /
• 제18권1호
• /
• pp.85-94
• /
• 1985

수치해법와 경험적 방법을 합성함으로써 하천수문곡선의 기저유출을 분리하는 방법을 개발하였다. 기저유출 감수곡선에 대해서는 선형화된 Boussinesq 방정식과 저유함수를 적용하였으며, 또한 강우에 의하여 지하의 대수층에 침투된 량이 하천으로 유입되는 기저유출의 추정에는 Singh과 Stall의 도식적 방법을 이용하였다. 이들에대한 시간별 연속성은 다원적인 다항식 회귀론에 의하여 근사화시켰다. 본 연구과정은 자연하천에 성공적으로 적용할 수 있었으나, 감수곡선을 위한 동차선형2단상징분계의 직접적 수치해법은 부적합한 것으로 나타났으며, 손실이 발생되는 부분침투천의 기저유량은 본 연구방법에 의하여 추정할 수 없었다.