RTT 측정을 이용하는 USN 기반 Networked Control System

이현철(Hyun-Chul Yi),김유종(Yu-Jong Kim),최준영(Joon-Young Choi) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.11

We design a NCS (Networked Control System) where the communication between sensors and controllers takes place over a USN (Ubiquitous Sensor Network). In order to measure time delays between sensors and controllers in real time, we design an algorithm to measure RTT (Round Trip Time) between USN nodes, and implement it into TinyOS of USN. By using the measured time delays, we construct the Smith predictor to compensate the time delays between sensors and controllers in real-time. For the real time experiment, we simulate the dynamic plant model, controller, and USN interface using Real-Time Windows Target provided in MATLAB. The USN interface in the Simulink model consists of serial ports, which connect the plant output and controller with USN nodes. The experiment results show that the time delays between sensors and controllers are precisely measured in real time; the Smith predictor appropriately compensates the time delays; and the stability is achieved in the closed-loop of the NCS.

임베디드 리눅스 기반 소프트웨어 PLC 구현

이현철(Hyun-Chul Yi),박재성(Jae-Sung Park),박준혁(Jun-Hyuk Park),이민철(Min-Cheol Lee),최준영(Joon-Young Choi) 한국정보기술학회 2014 한국정보기술학회논문지 Vol.12 No.7

We implement a Linux-based software PLC for embedded hardware systems, as modifying the Classic Ladder software PLC, which is an open source program for the desktop PC. In order to use the software PLC in the embedded system environment, we expand the functionality of the input devices, touch screen and USB keyboard. Moreover, GUI interfaces are newly designed and programed so that users can exploit the expanded functionality of the input devices. As a result, we become able to select, use input devices of the embedded linux-based software PLC in accordance with the special purpose and the environment, get the mobility or the portability of the embedded system, and reduce the construction costs of the automation control system. Using the simulation function supported by the Classic Ladder program, we experiment basic PLC operations and verify the validity of implementation.

USN에서 RTT 측정을 이용한 혼잡 추정 방법

이현철(Hyun-Chul Yi),최준영(Joon-Young Choi) 한국정보기술학회 2012 한국정보기술학회논문지 Vol.10 No.9

This paper proposes a congestion estimation method in USN(Ubiquitous Sensor Network) by using RTT(Round Trip Time) measurement. We design and implement the method of measuring RTT and estimating network congestion in the network layer of USN communication layer structure. Since RTT is a sensitive state variable to network congestion, the RTT based congestion estimation method is responsive to network congestion and appropriately represents the network congestion in real time. The RTT based congestion estimation method is designed by applying the congestion window calculation algorithm from FAST TCP. Experiment results verify that the proposed method appropriately measures the RTT and estimates the network congestion according to the variation of RTT values.

시대에 따른 슈퍼히어로의 변화를 통한 한국 영화 속 슈퍼히어로의 구현 방향성 모색 -크리스토퍼 놀란의 배트맨과 브라이언 싱어의 엑스맨을 중심으로-

이현철(주저자) ( Hyun Chul Yi ) 커뮤니케이션디자인학회 2014 커뮤니케이션 디자인학연구 Vol.49 No.-

한국에서 박스 오피스 집계가 시작된 2004년 한해한국영화 관람 관객 수는 3660만 명을 시작으로 2014년 1월부터 9월 현재까지 한국영화를 본 관람객 수가8500만 명을 넘어서고 있다. 2000년 이후 문화생활을 위한 다양한 포맷들이 정착되어 왔지만 영화는 아직까지도 문화체험의 큰 위치를 차지하고 있다. 2003년 이후 10년 동안 한국영화 시장은 상상할수 없을 만큼의 양적 성장을 가져왔다. 하지만 내용적 측면에서 콘텐츠의 다양한 해석 및 소재의 다양성을 시도해 보았지만 관객들로부터 만족할 만한 반응을 얻진 못했다. 2010년 이후 한국영화에는 조심스럽게 역사적 영웅을 소재로 한 영화들이 시작된다. 올 여름 개봉이후1700만 명이 본 ``명량``은 한국영화 역사상 박스 오피스 관객동원 1위의 새 역사를 쓰고 있다. 이 기록은 지금도 진행 중이다. 이 영화의 표면적 해석은 역사물에 기반을 둔 액션 드라마로 내면에는 한국형 슈퍼히어로를 만들어 보려는 적극적인 시도가 보인다. 이는 할리우드식 영화, 프랑스식 영화라는 성향을 구분 짖는 한국식 영화 장르의 시도라고 본다. 하지만 한국적 영웅의 시작 단계에서 보이는 역사적 소재를 통해 만들어진 슈퍼히어로는 콘텐츠 및 캐릭터의 평면적 구성으로 진부한 장르의 반복이라는 한계점을 드러내고 있다. 10년 전 할리우드의 영화는 슈퍼히어로 물을 다양한 장르에 적용 및 표면화 시켰다. 단순한 만화의 영웅이 이제는 여러 장르의 영화 속에서 고민하고 갈등하며 번뇌하는 영웅으로의 다양한 전개를 성공적으로 이어가고 있다. 이번 연구의 목적은 할리우드의 대표적인 영웅주의 영화 엑스맨 (브라이언 싱어 감독)과 배트맨 (크리스토퍼 놀란 감독)의 두 영화 속 스토리텔링과 캐릭터해석을 중점으로 한국의 영웅주의 영화 속에서 슈퍼히어로들이 추구해야 할 다양한 방향성을 찾아보고자 함에 목적을 둔다. Between January to September 2014, official box office statistics reported more than 85 million domestic viewers of Korean films, up from 36 million in 2004 alone, the year for which official box office statistics became first available. Various cultural activities including film, have been introduced and enjoyed from 2000, and movies still hold the majority share. Although the Korean movie market volume has increased dramatically since 2003 in the past decade, its experimentations in pursuit of various interpretations and topics with regards to content, has led to dissatisfied responses from audiences. 2010 marked the beginning of the release of historical heroic figure films. Myung Ryang has hit the all-time box office success with 17 billion audiences after its release this summer of 2014. The record is still climbing to an all-time high record. On the surface, the film is an action film based on historical events, but a closer examination suggests that the motive behind the plot may possibly be an attempt to create a brand new Korean film style, or "Korean-Style Superhero Film (KSF)," in the likes of Hollywood-style and French-style films. During this early stage of KSFs, signs of limitations as a superhero movie are still apparent, as their rather flat plots and characters of its superheroes are very much in line with the traditional historical drama film genres. Superhero movies in Hollywood have been crossed varied genres. In many different genres of film today, many of the past one .dimensional comics superheroes now lead various stories successfully with poignant moments of being confused, doubtful, and agonized as the plot develops. The research aims to elucidate the next directions KSF should take in order to create a more diverse character in a superhero in terms of its forms and sub-aspects. This is done by examining the storytelling and characters of two Hollywood hero films, X-men and Batman directed and produced by Bryan Singer and Christopher Nolan, respectively.

USN을 위한 RTT 기반 TCP 설계 및 구현

이현철(Hyun Chul Yi),최준영(Joon Young Choi) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.8

We design and implement a RTT (Round Trip Time) based TCP (Transmission Control Protocol) for USN (Ubiquitous Sensor Network). We adopt a basic update algorithm for window size from FAST TCP that uses the queuing delay at link as the congestion measure. The designed TCP estimates the queuing delay at link from the measured RTT in the network layer, and updates the window size based on the estimated queuing delay. The designed TCP allows to utilize the full capacity of USN links and avoids the waste of the given link capacity that is common without the flow control in the transport layer. The experiment results show that the window size of the sender converges within a small range of variations without any packet loss, and verify the stability and performance of the designed TCP.

입력 장치를 확장한 Ladder Logic Editor

이현철(Hyun-Chul Yi),최준영(Joon-Young Choi) 제어로봇시스템학회 2013 제어로봇시스템학회 각 지부별 자료집 Vol.2013 No.8

LTE 무선 네트워크에서의 TCP 성능 분석

이현철(Hyun-Chul Yi),김성용(Sung-Yong Kim),최준영(Joon-Young Choi) 한국정보기술학회 2013 한국정보기술학회논문지 Vol.11 No.5

In this paper, in order to analyze the dynamic property of data traffics in LTE(Long Term Evolution) mobile communication network, we build a dynamic model for LTE network in the packet level and implement the model based on NS-2 simulator. Using the implemented dynamic model for LTE network, we simulate TCP Reno with packet loss congestion measure and FAST TCP with queuing delay congestion measure in various LTE network environments and analyze the stability and performance of each TCP. The simulation results show that FAST TCP is superior to TCP Reno in performance over twice and illustrate that queuing delays contain more effective information on the network congestion than packet losses in the LTE network.

SCADA를 이용한 로직 에디터형 원격제어 컨트롤러 개발

박재성(Jae-Sung Park),이현철(Hyun-Chul Yi),박준혁(Jun-Hyuk Park),최준영(Joon-Young Choi),이민철(Min-Cheol Lee) 한국정보기술학회 2015 한국정보기술학회논문지 Vol.13 No.2

In this paper, We ported the PLC/HMI software to the embedded devices and constitute the inegrated PLC system. The reconfigured for small embedded development board selected the PLC software environment for embedded development research on existing and modified for opensource software in embedded systems OpenSCADA software to implement HMI. Porting the software PLC/HMI to the small embedded development board. After that verify that the PLC/HMI software is operating on an embedded hardware environment through simulation. As a result, it is available to use PLC and HMI on one embedded system without computer. It was able to reduce the design cost of the entire system does not require a separate license fees. And, not subject to case selected for the development of small embedded board space limitations. And, It is possible to indentify whether system error is logic problem or not as enabling monitoring of PLC software.

하드웨어 성능에 종속적인 EtherCAT 마스터 패킷 손실률 개선

안철진(Cheol-Jin An),이현철(Hyun-Chul Yi),김형우(Hyoung-Woo Kim),박성문(Sung-Mun Park),최준영(Joon-Young Choi) 한국정보기술학회 2015 한국정보기술학회논문지 Vol.13 No.4

We propose a packet sending and receiving algorithm for the reliable communication between master node and slave nodes in EtherCAT based network systems. The proposed algorithm is designed to efficiently prevent the packet loss whose occurrence frequency is dependent on hardware performance executing EtherCAT master. The algorithm is applied to open-source based IgH EtherCAT master stack by programming module and application, and is experimented by implementing EtherCAT network consisting of desktop computers with various performance levels and commercial EtherCAT slave devices. Through the experiment, we verify that the packet loss rate of the EtherCAT master depends on the hardware performance level and is improved by the proposed algorithm as preventing all the packet losses.

EtherCAT 네트워크 기반 리눅스 RTAI 개방형 CNC 시스템 구현

박성문,안철진,김형우,이현철,최준영,Park, Sung-Mun,An, Cheol-Jin,Kim, Hyoungwoo,Yi, Hyun-Chul,Choi, Joon-Young 제어로봇시스템학회 2015 제어·로봇·시스템학회 논문지 Vol.21 No.10

We propose a method for the implementation of an EtherCAT communication bus in a Linux-based open source Computerized Numerical Control (CNC) system. Recently, increasingly more CNC systems support real-time Ethernet protocols such as EtherCAT, which is a high-performance industrial communication protocol. For real-time CNC control over an Ethernet-based protocol, an additional layer driver needs to be implemented between the CNC system and the master of industrial communication protocol. Among the various solutions for the connection layer driver, we employ a Hardware Abstraction Layer (HAL) driver based on Linux. The operation of the implemented CNC system is demonstrated and confirmed by Hal Meter, which is used to observe the pins, signals, or parameters of HAL.