Controlled passive Anti-Rolling Tank의 제어기 개발

이현엽 忠南大學校 産業技術硏究所 2002 산업기술연구논문집 Vol.17 No.1

A controller for the passive anti-rolling tanks has been developed by using the 80196 microprocessor. Roll angles in a seaway has been measured with the inclinometer and the zero-crossing roll periods are measured continously. Digital and analogue filters are used to eliminate the noise from the measured data. Using the measured averaging roll periods of a ship, plates to adjust the fluid moving period in the tank are moved to the optimum locations successfully by the controller.

마이크로컨트롤러를 사용한 다중 데이터 모니터링 장치

이현엽 호남대학교 산업기술연구소 2000 산업기술연구논문집 Vol.8 No.-

이 논문은 8051 마이크로컨트롤러를 사용한 낮은 데이터 전송률을 갖는 다중 원격데이터 모니터링 장치에 대하여 다루었다. 구현된 장치는 Siemens의 80C535마이크로컨트롤러를 기반으로 8채널의 데이터 A/D 입력이 가능하고, 분산된 센서의 데이터를 획득하기 위하여 직렬통신을 사용한 멀티프로세서 형태로 구성하였다. 컨트롤러간 통신은 간단하며 효율적인 Master-Slave프로토콜을 사용하고 컨트롤러의 동작 불능시 Watchdog을 사용하여 원격에서 또는 차제적으로 시스템이 재가동 되도록 하였다. 호스트 컴퓨터가 시스템에 연결되지 않는 경우에는 각 컨트롤러가 데이터를 저장하도록 하고, 나중에 데이터의 처리 및 분석을 위하여 수집된 데이터를 다운받아 처리 하도록 하였다. This paper deals with a multiprocessor data collecting system with low data transfer rates which utilizes 8051 microcontrollers for remote data monitoring. The implemented system adapts Siemen's 80C535 microcontrollers which allow 8-channel A/D converter inputs from the sensors. The distributed microcontrollers are connected serially using the controller's serial I/O ports. The communication between controllers is established using a simple, but efficient master-slave protocols, and the watchdog is used to restart the system remotely or independently when the system fails. When the host PC is not connected to the system, each controllers collects and saves data which is later downloaded and processed for analysis and evaluation.

함정 탑재장비용 와이어로프 마운트 설계를 위한 기초연구

이현엽,김성은,김병현,곽정석 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.11

와이어로프 마운트는 함정에 탑재된 장비에 설치되어 진동, 충격 및 소음 등의 특수 성능을 만족시키게 한다. 이러한 와이어로프 마운트와 관련된 기술은 국내에서는 아직 완전하게 개발이 되지 않은 상태이다. 본 연구에서는 미 해군 규격 MIL-M-17185A와 MIL-S-901D를 기초하여 와이어로프 마운트의 기초연구를 진행하였다.

레일의 상하방향 불규칙성에 의한 차륜과 레일의 동접촉력

이현엽 대한기계학회 1997 대한기계학회 춘추학술대회 Vol.- No.-

한국군의 스트레스, 무망감, 우울이 자살생각에 미치는 영향: 탄력성의 중재효과

이현엽,강성록 육군사관학교 화랑대연구소 2011 한국군사학논집 Vol.67 No.1

This study has two aims: (1) to examine the associations between psychological risk factors (i.e., stress, hopelessness, and depression), resilience and suicidal ideation; (2) to examine whether resilience moderated the relationship between psychological risk factors and suicidal ideation. The present study included 500 military personnel of South Korea(Mage=21.72). Statistical measures of correlation and hierarchical multiple regression analysis were used to assess the relations between the variables. Results of this study are as follows. First, psychological risk factors were significantly and positively related to suicidal ideation. Second, hierarchical multiple regression analysis revealed that resilience moderated the relationship between stress,hopelessness, and depression and suicidal ideation. That is, the relationship between stress, hopelessness, and depression and suicidal ideation were conditional upon the level of resilience. The findings highlight the importance of resilience on preventing suicide. Furthermore, counseling or program for suicide prevention might be improved by paying attention to resilience. The implications of these findings are discussed.

Low-Power Switching Scheme with Quarter Reference Voltage Sources for SAR ADCs

이현엽,이진섭,노창현,강호진,김성태,백호선,김영진,조춘식 한국전자파학회 2022 Journal of Electromagnetic Engineering and Science Vol.22 No.2

In this paper, an energy-efficient switching scheme with additional quarter-reference voltage sources in a successive approximation register (SAR) analog-to-digital converter (ADC) is proposed for a low power and small area device for frequency modulated continuous wave (FMCW) radar transceivers. Recently, state-of-the-art ADCs have adopted a configuration that also uses Vref/2 as the reference voltage of the ADCs to improve the switching energy of capacitive digital-to-analog converter (CDAC). The proposed switching configuration additionally uses Vref/4 and 3Vref/4 reference voltages as the reference voltage of CDAC. Compared to state-of-the-art configurations that use the additional reference voltage of Vref /2, the average switching energy, and the total capacitance of CDAC in the proposed configuration are reduced by about 87.5% and 50%, respectively. In this switching scheme, the CDAC output voltage gradually converges to Vref/2, like with conventional SAR ADCs, which minimizes the dynamic offset that deteriorates the linearity of the SAR ADC.

서블릿을 이용한 인터넷 디스플레이 제어장치의 구현

이현엽 湖南大學校 情報通信硏究所 2002 정보통신연구 Vol.12 No.-

이 논문은 메시지 디스플레이에 이용되는 VFD와 같은 디스플레이를 인터넷을 통해 브라우져로 원격 디스플레이하는 장치에 대하여 연구하였다. 이 장치는 인터넷 접속기능을 지원하는 소형 OS를 갖춘 임베디드 프로세서를 사용하여 JAVA로 구성된 multi-thread Http와 디스플레이 서버를 작동하는, 디스플레이의 제어와 전송을 목적으로 브라우져에서 파라미터를 획득하기 위하여 서브릿 기능을 구현 후 프로그래밍하였다. 인터넷에 연결된 컨트롤러는 손쉬운 프로그래밍으로 웹을 통하요 디스플래이 장치를 원격으로 제어하거나 시스템 데이터의 모니터링이 가능하며, 이 분야의 다양한 응용시에 활용이 가능하다. This paper deals with the technique of remotely controlling through internet using conventional browsers the displaying units such as VFDs and LCDs which are used for displaying messages for various applications This system uses the internet-connectable embedded microcontrollers with tiny OS inside, and equipped with multi-threaded Java HTTP and display servers, while servlets are used to retrieve the parameters from the browsers and to transmit the system status to the client. The Internet-connected microcontroller enables the remote control and monitoring of display units through the web with moderate programming efforts, thus can be utilized in the various applications in this area.

인터넷 지문조회장치의 구현

이현엽 호남대학교 2002 호남대학교 학술논문집 Vol.23 No.2

This Paper deals with the technique of designing and implementing the fingerprint aquisition system which is consisted of fingerprint server and a small internet-connectable fingerprint terminal that uses a JVM-equiped microcontroller. Implemented fingerprint terminal is capable of stroing and recognizing upto 10 ingerprint images, and can be connected to the database of the fingerprint server through internet for further fingerprint inquiry and identification. This system improves portability by adapting internet connectable microcontrollers, and since it can be connected to the database of the server, this can be utilized in various related areas.

보강재의 운동으로 인한 보강판의 연성진동

李玄燁 홍익대학교 산업기술연구소 1996 産業技術 Vol.6 No.-

In a stiffened plate reinforced on one of its sides by beam type stiffeners. the asymmetry about the plate mid-plane induces coupling between flexural wave and longitudinal wave. In this research, interactions between flexural and longitudinal wave motion are analyzed in a stiffened plate which is reinforced only in one direction. The plate is modelled as a beam to which offset spring-mounted masses are attached at regular intervals. Propagation constants of the coupled waves and corresponding characteristic waves are derived by using periodic structure theory, and a computer code is developed. Also, sample calculations are carried out and the results are discussed.

마이크로컨트롤러 기반의 데스크탑 컴퓨터용 DMX-512 컨트롤러

이현엽 호남대학교 정보통신연구소 2000 정보통신연구 Vol.10 No.-

This paper deals with the PC based DMX-512 controller which is recently used widely in the lighting systems. By using DMX-512 protocols, designed boards can work in the IBM compatible PCs, and can control up to 512 illuminators or equivalent devices such as dimmers or multicoloring devices. Simulated Results show that the main system is suitable for the realization of DMX512 control protocols and assists the efficient control of upto 512 illuminators and dimmers as well as multicoloring capabilities. Developed system can replace the standard TTL gates to PLDs such as FPGA or CPLD chips which reduces the board areas, and thus can be utilized in the lighting systems having more sophisticated capabilities.