Core object: A data point is considered core if it
contains enough data points within a radius centered
on it and within a specified distance threshold (Chen,
2023).
Direct density reachability: For a core object, if a
data point is within the radius of the specified distance
threshold, the data point is considered to be directly
density reachable (Cohen, and Lefstein, et al. 2023).
Density connected: If a data point is both a core
object and another core object has a direct density
reachability, the two data points are considered to be
density connected (Gosztonyi, and Varga, 2023).
Cluster formation: By continuously adding
densely connected data points to the same cluster,
several clusters are eventually formed (Javier Robles-
Moral, and Fernandez-Diaz, et al. 2023).
Noise points: Data points that are not included in
any cluster are considered noise points (Jin, and Lu,
2023).
The advantage of the density clustering algorithm
is that it does not need to pre-set the number of
clusters, can automatically discover clusters in the
dataset, and has good fault tolerance for noise points.
1.3 Application of Density Clustering
Algorithm in the Classification of
Japanese Teaching Resources
In the classification of Japanese teaching resources,
the density clustering algorithm can be applied to two
aspects: grammar and vocabulary (Karol, and
Shaylor, et al. 2023).
1.3.1 Grammatical Classification
In grammatical classification, each sentence can be
regarded as a data point, and the similarity between
sentences can be judged by calculating the distance
between sentences, and similar sentences can be
placed in the same cluster. In the process of
grammatical classification, the subject, predicate,
object and other information of the sentence can be
added to the distance calculation, so as to make the
classification result more accurate (Kazima, and
Jakobsen, et al. 2023).
1.3.2 Vocabulary Classification
In lexical classification, you can think of each word
as a data point, calculate the distance between words,
judge the similarity between words, and put similar
words in the same cluster. In the process of
vocabulary classification, the part of speech,
meaning, frequency and other information of words
can be added to the distance calculation, so as to make
the classification results more accurate (Krieg, 2023).
1.4 Practical Application of Density
Clustering Algorithm in the
Classification of Japanese Teaching
Resources
1.4.1 Dataset Selection and Preprocessing
Choosing the right dataset is one of the keys to
classification. In Japanese language education,
datasets can be constructed by collecting various
teaching resources such as teaching materials,
listening materials, reading materials, etc. In the
preprocessing of a dataset, each data point can be
converted into a vector, adding different features to
the vector (Kwee, and Santos, 2023).
1.4.2 Practical Case Application
In practical case applications, the density clustering
algorithm can be applied to the classification of
Japanese teaching resources, such as classifying
Japanese textbooks and Japanese phonetic
vocabulary. In the process of classification, the
appropriate distance calculation method and density
threshold can be selected according to specific needs,
so as to obtain reasonable classification results.
1.5 Challenges of Density Clustering
Algorithm In The Classification Of
Japanese Teaching Resources
1.5.1 The Quality of the Dataset
The quality of the dataset directly affects the accuracy
of the classification results. How to ensure the quality
of data sets and avoid duplicate data and erroneous
data is one of the issues that need to be studied and
explored.
1.5.2 Selection of Distance Calculation
Method
The distance calculation method directly affects the
effectiveness and speed of classification. How to
choose the appropriate distance calculation method to
improve the accuracy and speed of classification is
also one of the problems that need to be studied and
discussed.