diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
new file mode 100644
index 0000000..0e8a64a
--- /dev/null
+++ b/.devcontainer/Dockerfile
@@ -0,0 +1,16 @@
+FROM mcr.microsoft.com/devcontainers/miniconda:0-3
+
+# Copy environment.yml (if found) to a temp location so we update the environment. Also
+# copy "noop.txt" so the COPY instruction does not fail if no environment.yml exists.
+COPY environment.yml* .devcontainer/noop.txt /tmp/conda-tmp/
+RUN if [ -f "/tmp/conda-tmp/environment.yml" ]; then umask 0002 && /opt/conda/bin/conda env update -n base -f /tmp/conda-tmp/environment.yml; fi \
+    && rm -rf /tmp/conda-tmp
+
+# [Optional] Uncomment to install a different version of Python than the default
+# RUN conda install -y python=3.6 \
+#     && pip install --no-cache-dir pipx \
+#     && pipx reinstall-all
+
+# [Optional] Uncomment this section to install additional OS packages.
+# RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+#     && apt-get -y install --no-install-recommends <your-package-list-here>
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
new file mode 100644
index 0000000..fd75e37
--- /dev/null
+++ b/.devcontainer/devcontainer.json
@@ -0,0 +1,43 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/miniconda
+{
+	"name": "Miniconda (Python 3)",
+	"build": {
+		"context": "..",
+		"dockerfile": "Dockerfile"
+	},
+	"customizations": {
+		"vscode": {
+			"extensions": [
+				"ms-python.python",
+				"ms-toolsai.jupyter"
+			]
+		}
+	},
+	"features": {
+		"ghcr.io/devcontainers/features/nvidia-cuda:1": {
+			"installCudnn": true
+		},
+		"ghcr.io/devcontainers/features/anaconda:1": {
+			"version": "latest"
+		},
+		"ghcr.io/devcontainers/features/python:1": {
+			"installTools": true,
+			"version": "3.9"
+		},
+		"ghcr.io/rocker-org/devcontainer-features/miniforge:1": {
+			"version": "latest",
+			"variant": "Miniforge-pypy3"
+		}
+	}
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	// "features": {},
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "python --version",
+	// Configure tool-specific properties.
+	// "customizations": {},
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}
\ No newline at end of file
diff --git a/.devcontainer/noop.txt b/.devcontainer/noop.txt
new file mode 100644
index 0000000..abee195
--- /dev/null
+++ b/.devcontainer/noop.txt
@@ -0,0 +1,3 @@
+This file is copied into the container along with environment.yml* from the
+parent folder. This is done to prevent the Dockerfile COPY instruction from 
+failing if no environment.yml is found.
\ No newline at end of file
diff --git a/.github/workflows/python-package-conda.yml b/.github/workflows/python-package-conda.yml
index 2f1a480..a0cb5f2 100644
--- a/.github/workflows/python-package-conda.yml
+++ b/.github/workflows/python-package-conda.yml
@@ -21,14 +21,6 @@ jobs:
       - name: Install dependencies
         run: |
           conda env update --file environment.yaml --name base
-      - name: Lint with flake8
+      - name: pso mnist run
         run: |
-          conda install flake8
-          # stop the build if there are Python syntax errors or undefined names
-          flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
-          # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-          flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
-      - name: Test with pytest
-        run: |
-          conda install pytest
-          pytest
+          python mnist.py
\ No newline at end of file
diff --git a/pso/optimizer.py b/pso/optimizer.py
index 556621e..dbf1bc0 100644
--- a/pso/optimizer.py
+++ b/pso/optimizer.py
@@ -90,7 +90,7 @@ class Optimizer:
                 negative_count += 1
                 
         print(f"negative swarm : {negative_count} / {self.n_particles}")
-        print(f"mutation swarm : {mutation_swarm*100/self.n_particles} / {self.n_particles}")
+        print(f"mutation swarm : {mutation_swarm * self.n_particles} / {self.n_particles}")
 
         gc.collect()
 
diff --git a/pso/particle.py b/pso/particle.py
index dcd7a92..57c7f39 100644
--- a/pso/particle.py
+++ b/pso/particle.py
@@ -150,9 +150,11 @@ class Particle:
                 + local_rate * r0 * (encode_p - encode_w)
                 + global_rate * r1 * (encode_g - encode_w)
             )
-        if np.random.rand() < self.mutation:
             
-            new_v += 0.5 * encode_v
+        if np.random.rand() < self.mutation:
+            m_v = np.random.uniform(-0.1, 0.1, len(encode_v))
+            new_v = m_v
+        
         self.velocities = self._decode(new_v, w_sh, w_len)
         
         del encode_w, w_sh, w_len
@@ -193,8 +195,11 @@ class Particle:
                 + local_rate * r0 * (w_p * encode_p - encode_w)
                 + global_rate * r1 * (w_g * encode_g - encode_w)
             )
-        if self.mutation:
-            new_v += 0.5 * encode_v
+            
+        if np.random.rand() < self.mutation:
+            m_v = np.random.uniform(-0.1, 0.1, len(encode_v))
+            new_v  = m_v
+            
         self.velocities = self._decode(new_v, w_sh, w_len)
         
         del encode_w, w_sh, w_len