• KIPS Transactions on Software and Data Engineering
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• v.11 no.6
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• pp.237-244
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• 2022

In this paper, we present VAE-based recommendation using online behavior log and purchase history to overcome data sparsity and cold start. To generate a variable for customers' purchase history, embedding and dimensionality reduction are applied to the customers' purchase history. Also, Variational Autoencoders are applied to online behavior and purchase history. A total number of 12 variables are used, and nDCG is chosen for performance evaluation. Our experimental results showed that the proposed VAE-based recommendation outperforms SVD-based recommendation. Also, the generated purchase history variable improves the recommendation performance.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.4
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• pp.53-67
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• 1998

This article investigates the potentialities of using empirical variables and their associated statistical relationships in document representation and retrieval. To this end, a newly devised empirical fact retrieval system was evaluated in comparison to a simulated traditional retrieval system involving a set of predetermined empirical queries. Results indicate that the EFRS generally outperformed the TRS in terms of the precision, search effort, and measures of user satisfaction.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.657-662
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• 1996

Meteorological and flux data measured from semiarid watersheds (Lucky Hills and Kendall) during the summer rainy and winter periods were used to study the sensitivity of the those variables used in the estimation of evapotranspiration rates. Relative sensitivity was examined to compare the importance of four meteorological and flux variables (net radiation wind speed, air temperature, and relative humidity) on Penman potential evapotranspiration (PET) estimation. The study results show that variations in Penman PET rates during the summer rainy period at both watersheds appears to be controlled by air temperature adn net radiation. During the winter period at both watersheds, wariations in Penman PET rates appears to be controlled by relative humidity and air temperature.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.1
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• pp.83-87
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• 2012

This study is aimed to identify latent classes which are based the change patterns in assistive technology device use among worker with disabilities and to test the effects of independent variables(gender, education, disability type, disability density, activity and participation of ICF: ICF, subjective socioeconomic status: SES, job satisfaction, life satisfaction) on determining latents classes. This study applied Nagin's(1999) semi-parametric group based approach to the panel survey of employment for the disabled. Because dependant variable has dichotomous scale, logit model was used. The results identified three latent classes, which could be defined based on the patterns as follows; assistive device continued use group, assistive device mid-level use group, assistive device sharp decline use group. The effects of the independent variables on the latent classes was tested by multinomial logit analysis. The results showed that education, disability type, ICF, SES, and life satisfaction were significant determinants of the latent classes. Finally, the implications based on analysis results were suggested.

• 한국노년학
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• v.29 no.4
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• pp.1611-1628
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• 2009

It is well known that health and psychosocial factors are closely associated with depressive symptoms. Due to limitations in available data and analysis methods, however, little is known about the effects of health and psychosocial factors on depression trajectory. In order to address the limitations, this study examines the predictors of depression trajectory using latent growth curve modeling involving individuals aged 60 and over who participated in the Korean Welfare Panel Study (N=4,919). Controlling for socioeconomic variables, health and psychosocial variables were cross-sectionally associated with depressive symptoms, which is consistent with previous findings. However, the effects of health and psychosocial variables on the rate of depressive symptom change varied. Health variables were significantly associated with the levels of depressive symptoms at wave 1, but these were not significantly associated with the rate of depressive symptoms change. By contrast, although psychosocial variables were significantly associated with depressive symptoms at wave 1, the effects of psychosocial variables on the rate of depressive symptom change varied. Specifically, while self-esteem and family relationship were positively associated with the rate of depressive symptom change, social relationship was negatively associated with the rate of depressive symptom change. Based on the findings, this study discussed implications for intervention and future research.

• Journal of Korea Game Society
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• v.9 no.3
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• pp.107-119
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• 2009

Online games belong to a technology-oriented service industry that has emerged from the assimilation of game contents and communication networks in the respective realms of culture technology (CT) and information technology (IT). This study examines the individual acceptance of online games as entertainment-oriented technology based on the belief-attitude-intention paradigm and the underlying hedonic and utilitarian motivations. To measure the latent variables influencing the acceptance process, a structured questionnaire was developed based on the existing Technology Acceptance Model. Research model analysis and hypothesis testing were carried out using a structural equation model. Results indicated that latent variables reflecting hedonic and utilitarian characteristics had a significant influence on user behavior in the acceptance of online games. By uncovering the core factors in! fluencing the acceptance of online games and thereby theoretically verifying the latent variables influencing the acceptance of entertainment-oriented technology, this study provides strategic implications for business models by game companies aimed at attracting a large user base and dominating the market.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.240-245
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• 2016

This study was conducted to predict the changes of potential distribution for invasive alien plant, Amaranthus viridis in Korea. The habitats of A. viridis were roadside, bare ground, farm area, and pasture, where the interference by human was severe. We used maximum entropy modeling (MaxEnt) for analyzing the environmental influences on A. viridis distribution and projecting on two different representative concentration pathways (RCP) scenarios, RCP 4.5 and RCP 8.5. The results of our study indicated annual mean temperature, elevation and precipitation of coldest month had higher contribution for A. viridis potential distribution. Projected potential distribution of A. viridis will be increased by 110% on RCP 4.5, 470% on RCP 8.5.

• Korea journal of population studies
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• v.15 no.2
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• pp.90-103
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• 1992

본 연구는 중국의 3개지역 (Hebei, Shaanxi, Shanghai)에서 한 자녀가족정책이 둘째 및 셋째 아이의 출산에 미치는 영향을 헤져드(Hazard) 모델을 이용하여 분석하고 있다. 특히, 그 정책효과의 도시와 농촌간의 격차, 현재자녀의 성구조에 따른 격차의 연구에 중점을 두고 있다. 연구자료는 1985년에 완료된 제 1단계 중국의 출산력 심층조사 (In-Depth Fertility Survey in China)를 이용하였다. 이 분석은 해져드 모델에서 각 시점의 한 자녀정책 전인지 후인지를 나타내는 시간에 따른 변동변수(time-varying variable)를 설명변수중의 하나로 포함시키고 그와 더불어 그 변수와 도시/농촌 주거여부를 나타내는 변수와의 혼합변수 (Interactive term) 및 현존자녀의 성구조와의 혼합변수를 포함하므로써 가능하게 된다. 또한, 자녀의 사망력이 차후 출산력에 미치는 영향을 비슷한 방법으로 분석하였다. 연구결과로는 첫째, 둘째 및 셋째 아이를 출산할 확률에 있어서 도시와 농촌격차가 한 자녀정책 실시 이후 더욱 커졌다는 사실이다. 이러한 결과는 부모가 생각하는 자녀의 가치가 도시에서 더 많이 저하했음을 제시하거나 정부의 한 자녀정책이 도시에서 더욱더 엄격히 집행되고 있음을 시사하고 있다. 둘째, Hebei와 Shanghai에서는 남아가 없는 부부가 남아를 가진 부부보다 둘째 또는 셋째아이를 가질 확률이 훨씬 높게 나타났다. 한편, Shanghai에서는 한 자녀정책 이후 둘째아이의 출산률이 첫째아이의 성에 관계없이 매우 낮았다. 이는 전통적으로 내려오는 남아선호 성향이 아직 농촌지역에서는 강하게 영향을 미치고 있지만 도시지역에서는 강력한 정책집행이 이를 억누르고 있음을 시사하고 있다. 하지만 Shanghai에서도 첫째아이가 사망한 경우 그 아이가 남아였으면 죽은아이가 여아이였을 경우보다 둘째아이의 출산이 훨씬 더 빠르게 나타나고 있음을 볼 때 도시에서도 여전히 남아선호 성향이 잠재하고 있음을 간접적으로 보여주고 있다.

• Journal of the Korean earth science society
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• v.33 no.7
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• pp.583-595
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• 2012

The potential for tropical cyclogenesis in a given oceanic and atmospheric environments can be represented by genesis potential index (GPI). Using the 18 Coupled Model Inter Comparison Project phase 5 (CMIP5) models, the annual cycle of GPI and interannual variability of GPI are analyzed in this study. In comparison, the annual cycle of GPI calculated from reanalysis data is revisited. In particular, GPI differences between CMIP5 models and reanalysis data are compared, and the possible reasons for the GPI differences are discussed. ENSO (El Nino and Southern Oscillation) has a tropical phenomenon, which affects tropical cyclone genesis and its passages. Some dynamical interpretations of tropical cyclogenesis are suggested by using the fact that GPI is a function of four large-scale parameters. The GPI anomalies in El Nino or La Nina years are discussed and the most contributable factors are identified in this study. In addition, possible dynamics of tropical cyclogenesis in the Northern Hemisphere Pacific region are discussed using the large-scale factors.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.127-138
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• 2020

This study investigated the patterns of transition of consumption patterns in Korean households in 2010 and 2017, and the impact of the life cycle on the transition of consumption patterns between the two time points. Using information on 4,717 households from the 2010 and 2017 data of the Korean Labor Panel Survey, we examined the effect of the family life cycle on changes in consumption patterns. The results of the latent transition analysis on the change in consumption type showed that the change in consumption type between the two points of time at the household level was relatively active. The logistic regression models reported that the transition of consumption type varies depending on the life cycle, such as changes in marital status, birth and independence of children. These results provide the implication that it is necessary to consider from the perspective of the family life course how the transition between their consumption types occurs when the government establishes consumption policies and companies set marketing target groups.