Fix bugs

app.py

@@ -10,7 +10,7 @@ import gradio as gr
 from jinja2 import Environment, FileSystemLoader
 
 from backend.query_llm import generate_hf, generate_openai
-from backend.semantic_search import retrieve
+from backend.semantic_search import retrieve, rerank
 
 
 TOP_K = int(os.getenv("TOP_K", 4))

backend/semantic_search.py

@@ -2,7 +2,6 @@ import lancedb
 import os
 import gradio as gr
 from sentence_transformers import SentenceTransformer, CrossEncoder
-from sklearn.metrics.pairwise import cosine_similarity
 import numpy as np
 import itertools