https://BolinWu-Gridea.github.io 2025-11-10T13:03:15.582Z https://github.com/jpmonette/feed Data Science Blog https://BolinWu-Gridea.github.io/images/avatar.png https://BolinWu-Gridea.github.io/favicon.ico All rights reserved 2025, Bolin Wu https://BolinWu-Gridea.github.io/post/survival-analysis-5-accelerated-failure-time-aft-model/ 2023-11-22T07:38:12.000Z

If we want to find the relationship between hazard function and other variables, we can use the Cox proportional hazards (PH) model. However, what if we want to model the survival time itself? In this case we can use Accelerated Failure-time (AFT) models.

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If we want to find the relationship between hazard function and other variables, we can use the Cox proportional hazards (PH) model. However, what if we want to model the survival time itself? In this case we can use Accelerated Failure-time (AFT) models.

]]> https://BolinWu-Gridea.github.io/post/survival-analysis-4-cox-proportional-hazards-model/ 2023-08-30T06:15:52.000Z

This post will briefly share the derivation, estimation, assumption and application of the Cox proportional hazards (PH) model. In addition, it will also mention using ANOVA to test two nested models.

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This post will briefly share the derivation, estimation, assumption and application of the Cox proportional hazards (PH) model. In addition, it will also mention using ANOVA to test two nested models.

]]> https://BolinWu-Gridea.github.io/post/survival-analysis-3-non-parametric-comparison-of-survival-functions/ 2023-07-27T08:34:25.000Z

This post is to share the two common non-parametric tests of comparing the survival functions: Log-Rank Test & Generalized Wilcoxon Test, as well as their corresponding calculations in the detailed process.

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This post is to share the two common non-parametric tests of comparing the survival functions: Log-Rank Test & Generalized Wilcoxon Test, as well as their corresponding calculations in the detailed process.

]]> https://BolinWu-Gridea.github.io/post/survival-analysis-2-non-parametric-estimation-of-survival-functions/ 2023-07-21T00:10:07.000Z

Concepts of survival function estimations and corresponding calculations both manually and in R.

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Concepts of survival function estimations and corresponding calculations both manually and in R.

]]> https://BolinWu-Gridea.github.io/post/survivalanalysis-1/ 2023-05-27T19:05:32.000Z

This post covers their concepts and relationship among the three pillows of survival analysis: survivor function, density function, hazard function.

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This post covers their concepts and relationship among the three pillows of survival analysis: survivor function, density function, hazard function.

]]> https://BolinWu-Gridea.github.io/post/network-influence-measures/ 2021-08-18T12:24:21.000Z

Closeness centrality can tell us how to find important nodes in a network. The important nodes could disseminate information to many nodes or prevent epidemics, or hubs in a transportaion network, etc.

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Closeness centrality can tell us how to find important nodes in a network. The important nodes could disseminate information to many nodes or prevent epidemics, or hubs in a transportaion network, etc.

]]> https://BolinWu-Gridea.github.io/post/network-connectivity/ 2021-08-11T13:54:08.000Z

In this post I will briefly share the connectivity related concepts and functions of clustering coefficient, distance measures, and connection robustness.

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In this post I will briefly share the connectivity related concepts and functions of clustering coefficient, distance measures, and connection robustness.

]]> https://BolinWu-Gridea.github.io/post/network-analysis-basics/ 2021-08-04T02:04:44.000Z

Networks is a set of objects (nodes) with interconnections (edges). Many complex structures can be represented by networks. It is everywhere in different forms. For example, family network, Facebook communication network, subway network, food web, etc.

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Networks is a set of objects (nodes) with interconnections (edges). Many complex structures can be represented by networks. It is everywhere in different forms. For example, family network, Facebook communication network, subway network, food web, etc.

]]> https://BolinWu-Gridea.github.io/post/semantic-text-similarity-and-topic-modeling/ 2021-07-26T23:47:50.000Z

Topic modeling is a useful tool for people to grasp a general picture of a long text document. Compared with LSTM or RNN, topic model is more or less for observatory purpose rather than prediction. In this post I will share the measure of similarity among words, the concept of topic modeling and its application in Python.

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Topic modeling is a useful tool for people to grasp a general picture of a long text document. Compared with LSTM or RNN, topic model is more or less for observatory purpose rather than prediction. In this post I will share the measure of similarity among words, the concept of topic modeling and its application in Python.

]]> https://BolinWu-Gridea.github.io/post/text-classification-in-python/ 2021-07-22T04:15:47.000Z

In the previous two posts, I have shared basic concepts and useful functions of text mining and NLP. In this third post of text mining in Python, we finally proceed to the advanced part of text mining, that is, to build text classification model. In this post I will share the main tasks of text classification. Two useful classification models, their implementation in Python and methods of improving classification performance.

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In the previous two posts, I have shared basic concepts and useful functions of text mining and NLP. In this third post of text mining in Python, we finally proceed to the advanced part of text mining, that is, to build text classification model. In this post I will share the main tasks of text classification. Two useful classification models, their implementation in Python and methods of improving classification performance.

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