diff --git "a/1_7.cpp_\352\270\260\354\264\210/.gitignore" b/1_7/.gitignore
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/.gitignore"
rename to 1_7/.gitignore
diff --git "a/1_7.cpp_\352\270\260\354\264\210/CMakeLists.txt" b/1_7/CMakeLists.txt
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/CMakeLists.txt"
rename to 1_7/CMakeLists.txt
diff --git "a/1_7.cpp_\352\270\260\354\264\210/Dockerfile" b/1_7/Dockerfile
similarity index 65%
rename from "1_7.cpp_\352\270\260\354\264\210/Dockerfile"
rename to 1_7/Dockerfile
index 5f680bd..8be71f3 100644
--- "a/1_7.cpp_\352\270\260\354\264\210/Dockerfile"
+++ b/1_7/Dockerfile
@@ -3,7 +3,7 @@ FROM slam:latest
 MAINTAINER changh95
 ARG DEBIAN_FRONTEND=noninteractive
 
-RUN cd fastcampus_slam_codes/'1_7.cpp_'$'\352\270\260\354\264\210' &&\
+RUN cd fastcampus_slam_codes/1_7 &&\
     mkdir build && cd build &&\
     cmake .. &&\
     make -j
diff --git "a/1_7.cpp_\352\270\260\354\264\210/examples/for_loop.cpp" b/1_7/examples/for_loop.cpp
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/examples/for_loop.cpp"
rename to 1_7/examples/for_loop.cpp
diff --git "a/1_7.cpp_\352\270\260\354\264\210/examples/map.cpp" b/1_7/examples/map.cpp
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/examples/map.cpp"
rename to 1_7/examples/map.cpp
diff --git "a/1_7.cpp_\352\270\260\354\264\210/examples/template_class.cpp" b/1_7/examples/template_class.cpp
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/examples/template_class.cpp"
rename to 1_7/examples/template_class.cpp
diff --git "a/1_7.cpp_\352\270\260\354\264\210/examples/template_function.cpp" b/1_7/examples/template_function.cpp
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/examples/template_function.cpp"
rename to 1_7/examples/template_function.cpp
diff --git "a/1_7.cpp_\352\270\260\354\264\210/examples/unordered_map.cpp" b/1_7/examples/unordered_map.cpp
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/examples/unordered_map.cpp"
rename to 1_7/examples/unordered_map.cpp
diff --git "a/1_7.cpp_\352\270\260\354\264\210/examples/vector.cpp" b/1_7/examples/vector.cpp
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/examples/vector.cpp"
rename to 1_7/examples/vector.cpp
diff --git "a/1_7.cpp_\352\270\260\354\264\210/examples/while_loop.cpp" b/1_7/examples/while_loop.cpp
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/examples/while_loop.cpp"
rename to 1_7/examples/while_loop.cpp
diff --git "a/1_7.cpp_\352\270\260\354\264\210/src/.gitkeep" b/1_7/src/.gitkeep
similarity index 100%
rename from "1_7.cpp_\352\270\260\354\264\210/src/.gitkeep"
rename to 1_7/src/.gitkeep
diff --git "a/2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/3d_pose_viewer.gif" b/2_2/3d_pose_viewer.gif
similarity index 100%
rename from "2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/3d_pose_viewer.gif"
rename to 2_2/3d_pose_viewer.gif
diff --git "a/2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/CMakeLists.txt" b/2_2/CMakeLists.txt
similarity index 100%
rename from "2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/CMakeLists.txt"
rename to 2_2/CMakeLists.txt
diff --git "a/2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/Dockerfile" b/2_2/Dockerfile
similarity index 100%
rename from "2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/Dockerfile"
rename to 2_2/Dockerfile
diff --git "a/2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/LICENSE" b/2_2/LICENSE
similarity index 100%
rename from "2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/LICENSE"
rename to 2_2/LICENSE
diff --git "a/2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/README.md" b/2_2/README.md
similarity index 100%
rename from "2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/README.md"
rename to 2_2/README.md
diff --git "a/2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/cam0_to_world.txt" b/2_2/cam0_to_world.txt
similarity index 100%
rename from "2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/cam0_to_world.txt"
rename to 2_2/cam0_to_world.txt
diff --git "a/2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/examples/pose_viewer.cpp" b/2_2/examples/pose_viewer.cpp
similarity index 100%
rename from "2_2.3d_\355\232\214\354\240\204\352\263\274_\354\235\264\353\217\231/examples/pose_viewer.cpp"
rename to 2_2/examples/pose_viewer.cpp
diff --git "a/2_6.Lie_Algebra_\354\213\244\354\212\265/CMakeLists.txt" b/2_6/CMakeLists.txt
similarity index 100%
rename from "2_6.Lie_Algebra_\354\213\244\354\212\265/CMakeLists.txt"
rename to 2_6/CMakeLists.txt
diff --git "a/2_6.Lie_Algebra_\354\213\244\354\212\265/Dockerfile" b/2_6/Dockerfile
similarity index 100%
rename from "2_6.Lie_Algebra_\354\213\244\354\212\265/Dockerfile"
rename to 2_6/Dockerfile
diff --git "a/2_6.Lie_Algebra_\354\213\244\354\212\265/LICENSE" b/2_6/LICENSE
similarity index 100%
rename from "2_6.Lie_Algebra_\354\213\244\354\212\265/LICENSE"
rename to 2_6/LICENSE
diff --git "a/2_6.Lie_Algebra_\354\213\244\354\212\265/README.md" b/2_6/README.md
similarity index 100%
rename from "2_6.Lie_Algebra_\354\213\244\354\212\265/README.md"
rename to 2_6/README.md
diff --git "a/2_6.Lie_Algebra_\354\213\244\354\212\265/examples/sophus_demo.cpp" b/2_6/examples/sophus_demo.cpp
similarity index 100%
rename from "2_6.Lie_Algebra_\354\213\244\354\212\265/examples/sophus_demo.cpp"
rename to 2_6/examples/sophus_demo.cpp
diff --git a/3_1.feature_detection_and_matching/CMakeLists.txt b/3_1.feature_detection_and_matching/CMakeLists.txt
deleted file mode 100644
index 132c8ac..0000000
--- a/3_1.feature_detection_and_matching/CMakeLists.txt
+++ /dev/null
@@ -1,64 +0,0 @@
-cmake_minimum_required(VERSION 3.10)
-project(
-	"CV_Project"
-	VERSION 0.1.0
-	LANGUAGES C CXX
-	)
-
-# Standard CMake modules
-include(CTest)
-include(CMakeDependentOption)
-include(GNUInstallDirs)
-include(InstallRequiredSystemLibraries)
-include(CMakePackageConfigHelpers)
-
-# Custom modules and scripts
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
-set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
-include(opencv)
-include(pcl)
-include(eigen)
-include(ceres)
-include(gtsam)
-include(pangolin)
-include(utils)
-#include(...)
-
-set(CMAKE_CXX_STANDARD 17)
-message(STATUS "-std=C++17")
-
-set(CMAKE_CXX_FLAGS "-Wall -Wextra")
-set(CMAKE_CXX_FLAGS "-O0")
-set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
-message(STATUS "-Wall -Wextra -O0")
-
-# 3rdParty dependencies
-#add_subdirectory(third_party EXCLUDE_FROM_ALL)
-
-set_property(GLOBAL PROPERTY USE_FOLDERS ON)
-
-# csv reader depdency
-set(THREADS_PREFER_PTHREAD_FLAG ON)
-find_package(Threads REQUIRED)
-
-find_package (Eigen3 3.3 REQUIRED NO_MODULE)
-set(BIN_FILE solution)
-set(BIN_FOLDER_PATH bin/)
-set(3RDPARTY_PATH 3rdParty/)
-
-include_directories(
-    include/
-    ${CMAKE_CURRENT_SOURCE_DIR}/src
-    include/fast-cpp-csv-parser/
-    ${Eigen3_INCLUDE_DIRS}
-)
-
-add_executable(${BIN_FILE}
-src/main.cpp
-)
-
-set_target_properties(${BIN_FILE} PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${BIN_FOLDER_PATH})
-
-target_link_libraries(
-	${OpenCV_LIBS}
-)
diff --git a/3_1.feature_detection_and_matching/examples/orb_feature_matching.cpp b/3_1.feature_detection_and_matching/examples/orb_feature_matching.cpp
deleted file mode 100644
index e69de29..0000000
diff --git a/3_1/CMakeLists.txt b/3_1/CMakeLists.txt
new file mode 100644
index 0000000..4a958dd
--- /dev/null
+++ b/3_1/CMakeLists.txt
@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.10)
+project("orb feature matching" LANGUAGES CXX)
+set(CMAKE_CXX_STANDARD 17)
+
+find_package(OpenCV REQUIRED)
+if (OpenCV_FOUND)
+    message(STATUS "Found OpenCV library: " ${OpenCV_INCLUDE_DIRS})
+    include_directories(${OpenCV_INCLUDE_DIRS})
+endif (OpenCV_FOUND)
+
+add_executable(orb_feature_matching examples/orb_feature_matching.cpp)
+target_link_libraries(orb_feature_matching ${OPENCV_LIBS})
\ No newline at end of file
diff --git a/3_1/examples/orb_feature_matching.cpp b/3_1/examples/orb_feature_matching.cpp
new file mode 100644
index 0000000..401b82f
--- /dev/null
+++ b/3_1/examples/orb_feature_matching.cpp
@@ -0,0 +1,7 @@
+#include <iostream>
+#include <opencv2/opencv.hpp>
+
+int main()
+{
+  std::cout << "hi!" << std::endl;
+}
\ No newline at end of file