diff --git a/src/3_13_Interpolation/3_13_interprolation.sc b/src/3_13_Interpolation/3_13_interprolation.sc
new file mode 100644
index 0000000..fafb307
--- /dev/null
+++ b/src/3_13_Interpolation/3_13_interprolation.sc
@@ -0,0 +1,55 @@
+/* 단순 참조 */
+//val name = "Buck Trends"
+//println(s"Hello, ${name}")
+
+
+val number = 3.14
+/*중괄호 없이, 숫자->문자*/
+//println(s"Hello, $number")
+
+/* $표시 */
+//println("$") // $출력
+//println(s"$")  // s를 붙이면 $는 인터폴레이선 처리를 위해 에러가 발생
+//println(s"$$")  // $를 사용하기 위해서는 $$를 사용해야한다.
+//println(f"$$")  // $를 사용하기 위해서는 $$를 사용해야한다.
+
+/* s 와 f의 차이 */
+//println(s"$number%.4f")
+/*
+   s로 하게 되면 인터폴레이션만 처리
+   f로 하게되면 포맷터 사용
+*/
+
+/*
+  printf 형식화를 위해 자바의 Formatter를 사용.
+ */
+//println(f"$number%.4f")
+//printf(f"$number%.4f\n") // printf로도 사용가능
+
+//val fNum = f"$number%.4f" //String 타입으로 저장
+//println(s"==> $fNum")
+
+
+//val gross = 100000F
+//val net = 64000F
+//val percent = (net / gross * 100)
+//println(f"$$${gross}%.2f vs. $$${net}%.2f or ${percent}%.1f%%")
+//println(f"$$$gross%.2f vs. $$$net%.2f or $percent%.1f%%")
+
+
+//val i = 200
+
+//f"${i}%.2f" // i 는  Int형이나 암시적 변환이 적용되어 float형으로 포맷처
+
+//val d = 100.22
+
+//f"${d}%2d"  // Double을 Int로 표현하려고 시도해서 컴파일 오류
+
+//val s = "%02d: name = %s".format(5, "Dean Wampler")
+
+
+//val name = "Dean Wampler"
+//
+//s"123\n$name\n456"
+//
+//raw"123\n$name\n456"
diff --git a/src/3_14_Trait/3_14_trait.sc b/src/3_14_Trait/3_14_trait.sc
new file mode 100644
index 0000000..6a80e2f
--- /dev/null
+++ b/src/3_14_Trait/3_14_trait.sc
@@ -0,0 +1,45 @@
+
+class ServiceImportante(name: String) {
+  def work(i: Int): Int = {
+    println(s"ServiceImportante: Doing important work! $i")
+    i+1
+  }
+}
+
+val service1 = new ServiceImportante("uno")
+(1 to 3) foreach (i => println(s"Result: ${service1.work(i)}"))
+
+
+
+trait Logging {
+  def info   (message:String): Unit
+  def warning(message:String): Unit
+  def error  (message:String): Unit
+}
+
+trait StdoutLogging extends Logging {
+  def info    (message:String) = println(s"INFO:    $message")
+  def warning (message:String) = println(s"WARNING: $message")
+  def error   (message:String) = println(s"ERROR    $message")
+}
+
+trait StdoutLoggin2 {
+  def debug   (message:String) = println(s"DEBUG:   $message")
+  def value   (message:String) = println(s"Value:   $message")
+}
+
+
+val service2 = new ServiceImportante("dos") with StdoutLogging with  StdoutLoggin2 {
+  override def work(i: Int): Int = {
+    info(s"String work: i = $i")
+    val result = super.work(i)
+    info(s"Ending work: i = $i, result = $result")
+    debug(s"Debug")
+    result
+  }
+}
+(1 to 3) foreach (i => println(s"Result: ${service2.work(i)}"))
+
+class LoggedServiceImportante(name: String)
+  extends ServiceImportante(name) with StdoutLogging {
+}
\ No newline at end of file
diff --git a/src/3_14_Trait/LogginScala.scala b/src/3_14_Trait/LogginScala.scala
new file mode 100644
index 0000000..8e4ca6f
--- /dev/null
+++ b/src/3_14_Trait/LogginScala.scala
@@ -0,0 +1,10 @@
+package Trait3_14
+
+/**
+  * Created by Neo on 2016-08-22.
+  */
+trait LoggingScala {
+  def info   (message:String): Unit
+  def warning(message:String): Unit
+  def error  (message:String): Unit
+}
\ No newline at end of file
diff --git a/src/3_14_Trait/LoggingJava.java b/src/3_14_Trait/LoggingJava.java
new file mode 100644
index 0000000..9c18b7e
--- /dev/null
+++ b/src/3_14_Trait/LoggingJava.java
@@ -0,0 +1,10 @@
+package Trait3_14;
+
+/**
+ * Created by Neo on 2016-08-22.
+ */
+public interface LoggingJava {
+    void info(String message);
+    void warning(String message);
+    void error(String messae);
+}
diff --git a/src/3_14_Trait/ServiceImportanateScala.scala b/src/3_14_Trait/ServiceImportanateScala.scala
new file mode 100644
index 0000000..dbc8ac8
--- /dev/null
+++ b/src/3_14_Trait/ServiceImportanateScala.scala
@@ -0,0 +1,11 @@
+package Trait3_14
+
+/**
+  * Created by Neo on 2016-08-22.
+  */
+class ServiceImportanteScala(name: String) {
+  def work(i: Int, j: Int): Int = {
+    println(s"ServiceImportante: Doing important work! $i")
+    i+1
+  }
+}
diff --git a/src/3_14_Trait/StdoutLoggingScala.scala b/src/3_14_Trait/StdoutLoggingScala.scala
new file mode 100644
index 0000000..5295e95
--- /dev/null
+++ b/src/3_14_Trait/StdoutLoggingScala.scala
@@ -0,0 +1,10 @@
+package Trait3_14
+
+/**
+  * Created by Neo on 2016-08-22.
+  */
+trait StdoutLoggingScala extends LoggingJava {
+  def info    (message:String) = println(s"INFO:    $message")
+  def warning (message:String) = println(s"WARNING: $message")
+  def error   (message:String) = println(s"ERROR    $message")
+}
diff --git a/src/3_14_Trait/TestService2.scala b/src/3_14_Trait/TestService2.scala
new file mode 100644
index 0000000..68728d9
--- /dev/null
+++ b/src/3_14_Trait/TestService2.scala
@@ -0,0 +1,20 @@
+package Trait3_14
+
+/**
+  * Created by Neo on 2016-08-22.
+  */
+
+object TestService2 {
+  def main(args: Array[String]): Unit = {
+    val service2 = new ServiceImportanteScala("dos") with StdoutLoggingScala {
+      override def work(i: Int, j:Int): Int = {
+        info(s"String work: i = $i")
+        val result = super.work(i,3)
+        info(s"Ending work: i = $i, result = $result")
+        result
+      }
+    }
+    (1 to 3) foreach (i => println(s"Result: ${service2.work(i,3)}"))
+  }
+
+}
diff --git a/src/3_14_Trait/stack_modification.sc b/src/3_14_Trait/stack_modification.sc
new file mode 100644
index 0000000..c3c098e
--- /dev/null
+++ b/src/3_14_Trait/stack_modification.sc
@@ -0,0 +1,73 @@
+/***
+트레이트로 확장되는 정수형 큐 예제
+***/
+//정수형 큐의 추상화 클래스
+abstract class IntQueue {
+  def get() : Int
+  def put(x:Int)
+}
+
+//큐기능 구현
+import scala.collection.mutable.ArrayBuffer
+class BasicIntQueue extends IntQueue {
+  private var buf = new ArrayBuffer[Int]
+  def get() = buf.remove(0)
+  def put(x: Int) {buf += x}
+}
+
+/////실행부 q1
+val q1 = new BasicIntQueue
+q1.put(10)
+q1.put(20)
+q1.get()
+q1.get()
+
+
+// 더블링 트레이트 정의 ( *2 )
+trait Doubling extends IntQueue {
+  abstract override def put(x: Int) {super.put(2 * x)}
+}
+
+//기본 정수큐 상속 및 더블링큐 믹스
+class MyQueue extends BasicIntQueue with Doubling {
+}
+
+//더블링 큐 실행테스트
+val q2 = new MyQueue
+q2.put(10)
+q2.get()
+
+
+//숫자 +1증가 트레이트 정의
+trait Incrementing extends IntQueue {
+  abstract override def put(x: Int): Unit = {super.put(x+1)}
+}
+
+// 음수 제거 트레이트 정의
+trait Filtering extends IntQueue {
+  abstract override def put(x: Int) {if (x >= 0) super.put(x)}
+}
+
+/// 기본정수큐 와 1증가, 필터링 트레이트 믹스 테스트
+val q3 = (new BasicIntQueue with Incrementing with Filtering)
+//q3.put(-1)
+//q3.put(0)
+//q3.put(1)
+//q3.get()
+//q3.get()
+
+
+/// stack modification
+// 값을 증가하고 필터링이 되었으면 값이 3개가 들어가야하나
+// 필터링->숫자+1증가 순서로 진행
+// trait가 stack modification 기능을 제공하는지 이해할 수 있음.
+
+
+//추가 테스트
+val q4 =(new BasicIntQueue with Incrementing with Doubling with Filtering)
+q4.put(-10) //필터링
+q4.put(0)  // 필터링 -> 더블링:0 -> 1증가:1 -> 큐삽입
+q4.put(10) // 필터링 -> 더블링:20 -> 1증가:21 -> 큐삽입
+q4.get() // 1
+q4.get() // 21
+q4.get() // 에러~ -10 필터링됨.