Evolving Recommender System for Mobile Apps

Xiao Xia,Xiaodong Wang,Xingming Zhou 한국산학기술학회 2013 SmartCR Vol.3 No.3

The explosive growth of mobile apps gives rise to the significant challenge of app discovery. For this reason, Google Play utilizes a collaborative filtering approach for recommending apps to users by analyzing user behavior. Those recommendations help users discover apps by referring to the experiences of other users. However, their choices may also be limited because most users only know about a limited number of apps. To eliminate such constraints, we propose a novel recommendation method utilizing global information about apps. We generate recommendations by both analyzing the metadata and measuring the similarity between apps, leveraging the Latent Semantic Index method. To understand both methods, we further measure the diversity within them. Through those measurements, we not only gain better understanding of both recommendation methods but also discover new knowledge about user preferences. Such measurements also identify the necessity and potential to evolve the existing system. We therefore propose a diversity measurement?based evolution framework for the development of mobile app recommender systems. To implement the framework, we further model the system evolution as a multi-criteria optimization problem and design a rank aggregation scheme to solve it. Preliminary evaluations verified the promising effectiveness of our framework and method based on a data set of 103,348 apps.

한·중 연어 대조를 위한 연어 개념 구축과 범주 한정

소효하 ( Su¸ Xiao-xia ),최순희 ( Cui¸ Shun-ji ) 한민족어문학회 2021 韓民族語文學 Vol.- No.93

본 연구는 한국어 '연어'(collocation)와 중국어 '搭配'를 논의함으로써 한·중 연어 대조를 위한 연어 개념을 구축하는 데 목적을 둔다. 최근 한·중 연어 대조 연구가 활발해진 것에 비하면 한국어 연어에 상응하는 중국어 개념에 대한 이론적 논의가 많이 부족하다. 영어 'collocation'에 대하여 일반적으로 한국어에서는 연어라고, 중국어에서는 '搭配'라고 한다. 본고는 한국어 연어와 중국어 搭配에 관한 논의를 살펴봄으로써 두 가지 개념은 일치하지 않는다고 지적하였다. 그리고 搭配의 유형을 분석한 결과 特定搭配/有限组合/受限搭配/限制性搭配 등을 한국어 연어에 상응하는 개념으로 볼 수 있으며, 이 중 본고에서 주장하는 연어 판별 기준을 고려해 '特定搭配'가 가장 적합하다고 보았다. 또한 일차적으로 '의미 해석의 투명성'을, 이차적으로 '어휘 선택 제약'을 연어와 特定搭配를 판별하는 기준으로 제시하고 그들의 범주를 규정하였다. The purpose of this study was to establish the concept of collocation for the Korean-Chinese collocation contrast by discussing Korean "collocation" and Chinese "搭配". Compared to recent active studies on Korean-Chinese collocation, there is a lack of theoretical discussion on Chinese concepts corresponding to Korean collocation. This paper points out that these two concepts do not match, looking at discussions on Korean collocation and Chinese 搭配. After analyzing the type of 搭配, "特定搭配/有限组合/受限搭配/限制性搭配" can be considered as a corresponding concept to Korean collocation, among which "特定搭配" is the most appropriate one considering the collocation discrimination criteria proposed in this paper. In addition, in terms of the criteria for collocation or 特定搭配, this study proposed "meaning interpretation of transparency" as the primary criterion and "lexical selection restrictions" as the secondary standard. This study also specified their category.

Gene expression involved in dark-induced leaf senescence in zoysiagrass (Zoysia japonica)

Xiaoxia Cheng,Xiaomei Dai,Huiming Zeng,Yunxia Li,Wei Tang,Liebao Han 한국식물생명공학회 2009 Plant biotechnology reports Vol.3 No.4

Zoysiagrass (Zoysia japonica) is one of the important turfgrass species. Extending green period of zoysiagrass via delaying leaf senescence will make this species have more potential in the turfgrass industry. In this study, we found that zoysiagrass seedlings treated with GA3 could delay the leaf senescence induced by darkness. To study expression of genes responsive to staying green in zoysiagrass, suppression subtractive hybridization (SSH) was used to identify differentially expressed genes between non-GA3-treated and GA3-treated seedlings subjected to darkness. A total of 307 ESTs were generated, of which 226 ESTs clustered into 54 contigs and 81 were singlets. Differentially expressed genes selected by subtractions were classified into six categories according to their putative functions generated by BLAST analysis. Expression of five selected genes, Met, SAM, V-ATPase, Cry (Cryptochrome gene), and An (diphthine synthase gene) were examined by RT-PCR and Real-time PCR. Both RT-PCR and Real-time PCR results demonstrated that the differential expressions of these genes were attributable to delaying senescence by exogenously applied gibberellic acid. This is the first genome-wide study of senescence in a species of turfgrass. Zoysiagrass (Zoysia japonica) is one of the important turfgrass species. Extending green period of zoysiagrass via delaying leaf senescence will make this species have more potential in the turfgrass industry. In this study, we found that zoysiagrass seedlings treated with GA3 could delay the leaf senescence induced by darkness. To study expression of genes responsive to staying green in zoysiagrass, suppression subtractive hybridization (SSH) was used to identify differentially expressed genes between non-GA3-treated and GA3-treated seedlings subjected to darkness. A total of 307 ESTs were generated, of which 226 ESTs clustered into 54 contigs and 81 were singlets. Differentially expressed genes selected by subtractions were classified into six categories according to their putative functions generated by BLAST analysis. Expression of five selected genes, Met, SAM, V-ATPase, Cry (Cryptochrome gene), and An (diphthine synthase gene) were examined by RT-PCR and Real-time PCR. Both RT-PCR and Real-time PCR results demonstrated that the differential expressions of these genes were attributable to delaying senescence by exogenously applied gibberellic acid. This is the first genome-wide study of senescence in a species of turfgrass.

Rapid Detection of Noroviruses in Fecal Samples and Shellfish by Nucleic Acid Sequence-based Amplification

Xiaoxia Kou,Qingping Wu,Jumei Zhang,Hongying Fan 한국미생물학회 2006 The journal of microbiology Vol.44 No.4

The purpose of this study was to determine the efficacy of a nucleic acid sequence-based amplification (NASBA) method of detecting noroviruses in artificially and naturally contaminated shellfish. We used 58 fecal samples that tested positive for noroviruses with electron microscopy (EM) to develop an NASBA assay for these viruses. Oligonucleotide primers targeting the polymerase coding region were used to amplify the viral RNA in an isothermal process that resulted in the accumulation of RNA amplicons. These amplicons were detected by hybridization with digoxigenin-labeled oligonucleotide probes that were highly specific for genogroup I (GI) and genogroup II (GII) of noroviruses. The expected band of 327 bp appeared in denaturing agarose gel without any nonspecific band. The specific signal for each amplicon was obtained through Northern blotting in many repeats. All fecal samples of which 46 (79.3%) belonged to GII and 12 (20.6%) belonged to GI were positive for noroviruses by EM and by NASBA. Target RNA concentrations as low as 5 pg/ml were detected in fecal specimens using NASBA. When the assay was applied to artificially contaminated shellfish, the sensitivity to nucleic acid was 100 pg/1.5 g shellfish tissue. The potential use of this assay was also confirmed in naturally contaminated shellfish collected from different ponds in Guangzhou city of China, of which 24 (18.76%) out of 128 samples were positive for noroviruses; of these, 19 (79.6%) belonged to GII and 5 (20.4%) belonged to GI. The NASBA assay provided a more rapid and efficient way of detecting noroviruses in fecal samples and demonstrated its potential for detecting noroviruses in food and environmental samples with high specificity and sensitivity.

Investigation of a Plasma-Etching Process That Uses a Porous Dielectric Template

Xiaoxia Zhong,Luqi Yuan,Xiaochen Wu,Qiwei Shu,Yuxing Xia 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.4

A plasma etching proces of GaN films that used a porous dielectric template was investigated by using numerical simulations. The electrical field, caused by both the substrate bias and the charges acumulated on the insulating template surface, was asumed to affect ions trajectories. Reactive ions enter the sheath with a velocity calculated by using a maxwelian distribution. We found that the microscopic electrical field over the template could change the ion movement. The substrate potential and the nanopore structure showed an ability to affect the etching rate. A peak value of the reactive etching species could be found on the lateral wal in the nanopores. Changing the parameters helped to weaken the peak and, hence, to make the etching proces more effective. The work reported here may help people to understand plasma etching using a porous alumina template.

Attractors and quasi-attractors of a flow

XIAOXIA WANG,CHUNYAN ZUO 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.23 No.1

In this paper, the connection among the attractor, the attractor neighborhood and the domain of influence are investigated. A necessary and sufficient condition of the existence of the quasi-attractor is established. Some results of Conley in [2] are generalized.

Study on Fuzzy Catastrophe Risk Model Based on Fuzzy Theory

Xiaoxia Zhu 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8

In this paper, we analyzed the essential meaning of the catastrophe risk on the basis of many results that is the bottleneck of the catastrophe risk analysis is complex. One way to resolve or alleviate this problem is to analyze the risk from the viewpoint of fuzzy logic-fuzzy catastrophic risk (FCR) analysis. We propose the concept of synthetic effect, present its axiomatic foundation, and further establish a FCR model based on synthetic effect as well as the general solution model. Finally, we specify the model by considering catastrophe risk in Shanghai. The results indicate that the method is not only accommodates the existing fuzzy decision-making methods, but also successfully incorporates the decision preference into the optimization process. Therefore, the FCR model can be widely used in many fields such as complex systems optimization and decision-making.

Beijing Practices Tackling Climate Change

Xiaoxia Wang 서울시립대학교 도시과학연구원 2008 도시과학국제저널 Vol.12 No.1

Impacts of global climate change on Beijing is likely to focus not on climate changes in isolation but on interactions between climate change and other stresses on the city’s growth and development. Beijing’s vulnerabilities related to climate change include an increase in annual average temperatures, possible reductions in average rainfall and run-off, and more heat waves and fewer frosts. Beijing’s GHGs emission from energy consumption is calculated to be nearly 35 million tons of CO2 in 2005. Changing trends of Beijing’s GHGs (Green House Gas) from other sources have been predicted. Beijing’s responses and actions of mitigation and adaptation to climate change are analyzed under a background of the 2008 Olympic Games with particular attention from 2001. Impacts of global climate change on Beijing is likely to focus not on climate changes in isolation but on interactions between climate change and other stresses on the city’s growth and development. Beijing’s vulnerabilities related to climate change include an increase in annual average temperatures, possible reductions in average rainfall and run-off, and more heat waves and fewer frosts. Beijing’s GHGs emission from energy consumption is calculated to be nearly 35 million tons of CO2 in 2005. Changing trends of Beijing’s GHGs (Green House Gas) from other sources have been predicted. Beijing’s responses and actions of mitigation and adaptation to climate change are analyzed under a background of the 2008 Olympic Games with particular attention from 2001.

Peer Effect in Spreading Network of Fake Information in Public Crisis

Xiaoxia Zhu,Mengmeng Liu,Haiju Hu 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.12

Direct Multiple Shooting Induction of Taraxacum

Xiaoxia Gou,홍순관,김재학 한국자원식물학회 2009 한국자원식물학회지 Vol.22 No.6

Plants of the genus Taraxacum are well-known as a traditional herbal remedy with a long history, and they have also been extensively used as food, chemicals and cosmetics. In this study, four Taraxacum species distributed in Korea (T. mongolicum, T. officinale, T. mongolicum variation and T. officinale variation) were utilized for an efficient method for direct multiple shooting induction and regeneration, using leaf blade, transition zone, petiole and root as explants in MS media with various hormone concentration and combination. MS medium containing IAA 0.2 mg/L and TDZ 1.0 mg/L showed the highest induction frequency of all the hormone combinations. Besides, the induction of T. mongolicum variation was most effective comparing with the other three species by the average induction frequency of four explants. While the induction effect of leaf blade explant was more obvious than the other three explants. This system exhibited a rapid propagation of shoots from the leaf blade explants and makes it convenient to make use of these Taraxacum species to develop their diverse applications in the future.