SAP ERP 시스템 교육을 위한 교육용 가상기업 구현 전략

김영렬(Young-Real Kim) 한국산업정보학회 2011 한국산업정보학회논문지 Vol.16 No.1

본 논문은 대학에서의 SAP R/3를 이용한 ERP 교육을 하는데 있어서 실습의 중요성을 강조하고 실습의 효과를 높이기 위해서 교육용 가상기업을 생성할 필요성을 주창하고 있다. SAP R/3 시스템에서 교육생들이 직접 가상 기업을 설정하고, 해당 모듈 내에서 프로세스를 생성하는 것을 직접 구현 한 사례를 보여줌으로써 ERP 교육의 효과를 보다 높일 수 있는 새로운 실습 교육 방법을 제시하고 있다. Among the various ERP solutions, SAP R/3 solution has been chosen because SAP system follows global standard processes which include most of business solutions for various industries. The ERP education is limited by learning theory only and they are not sufficient for understanding wide scale of business processes. Real world scenarios with hands on experience approach will be the core aspect of this article. As per real world scenarios, "ChungBuk Motors. Corp." has been created and students are asked to create the organization structure and the procurement process for this virtual enterprise. As a result, students attending this class showed better understanding of overall ERP system comparing to the students attended other ERP classes. The hands-on experience with real-world scenarios proved that it is most practical and efficient solution for educating ERP system.

Sensorless Detection of Position and Speed in Brushless DC Motors using the Derivative of Terminal Phase Voltages Technique with a Simple and Versatile Motor Driver Implementationr

José Carlos Gamazo Real,Jaime Gómez Gil 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

The detection of position and speed in BLDC motors without using position sensors has meant many efforts for the last decades. The aim of this paper is to develop a sensorless technique for detecting the position and speed of BLDC motors, and to overcome the drawbacks of position sensorbased methods by improving the performance of traditional approaches oriented to motor phase voltage sensing. The position and speed information is obtained by computing the derivative of the terminal phase voltages regarding to a virtual neutral point. For starting-up the motor and implementing the algorithms of the detection technique, a FPGA board with a real-time processor is used. Also, a versatile hardware has been developed for driving BLDC motors through pulse width modulation (PWM) signals. Delta and wye winding motors have been considered for evaluating the performance of the designed hardware and software, and tests with and without load are performed. Experimental results for validating the detection technique were attained in the range 5-1500 rpm and 5-150 rpm under no-load and full-load conditions, respectively. Specifically, speed and position square errors lower than 3 rpm and between 10º-30º were obtained without load. In addition, the speed and position errors after full-load tests were around 1 rpm and between 10º-15º, respectively. These results provide the evidence that the developed technique allows to detect the position and speed of BLDC motors with low accuracy errors at starting-up and over a wide speed range, and reduce the influence of noise in position sensing, which suggest that it can be satisfactorily used as a reliable alternative to position sensors in precision applications.

Sensorless Detection of Position and Speed in Brushless DC Motors using the Derivative of Terminal Phase Voltages Technique with a Simple and Versatile Motor Driver Implementation

Jose Carlos Gamazo Real,Jaime Gomez Gil 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.4

The detection of position and speed in BLDC motors without using position sensors has meant many efforts for the last decades. The aim of this paper is to develop a sensorless technique for detecting the position and speed of BLDC motors, and to overcome the drawbacks of position sensorbased methods by improving the performance of traditional approaches oriented to motor phase voltage sensing. The position and speed information is obtained by computing the derivative of the terminal phase voltages regarding to a virtual neutral point. For starting-up the motor and implementing the algorithms of the detection technique, a FPGA board with a real-time processor is used. Also, a versatile hardware has been developed for driving BLDC motors through pulse width modulation (PWM) signals. Delta and wye winding motors have been considered for evaluating the performance of the designed hardware and software, and tests with and without load are performed. Experimental results for validating the detection technique were attained in the range 5-1500 rpm and 5-150 rpm under no-load and full-load conditions, respectively. Specifically, speed and position square errors lower than 3 rpm and between 10°-30° were obtained without load. In addition, the speed and position errors after full-load tests were around 1 rpm and between 10°-15°, respectively. These results provide the evidence that the developed technique allows to detect the position and speed of BLDC motors with low accuracy errors at starting-up and over a wide speed range, and reduce the influence of noise in position sensing, which suggest that it can be satisfactorily used as a reliable alternative to position sensors in precision applications.

해상 NB-IoT 서비스를 위한 ICS RF 중계기

조신호 ( Sin-ho Cho ),이성렬 ( Seong-real Lee ) 한국항행학회 2021 韓國航行學會論文誌 Vol.25 No.5

본 연구에서는 해양수산부가 2016년 실행 계획을 발표한 전자어구 실명제를 실현할 수 있는 어구 자동식별 모니터링 시스템에서 통신 거리를 늘릴 수 있는 해상 중계기 설계와 제작에 대해 보고한다. 해상 중계기는 중계기를 구성하는 서비스 안테나와 링크 안테나 사이의 되먹임 신호에 의한 발진을 제거할 수 있는 ICS (interference cancellation system) 방식의 RF 중계기로 설계 제작하였다. ICS RF 중계기 설계에 있어 링크 안테나와 서비스 안테나 간 이격을 30 dB 확보하였다. 시험을 통한 검증 결과 ICS RF 중계기의 출력 신호 일부가 입력으로 되먹임되는 신호 레벨이 중계기 이득보다 15 dB 이상 낮을 때 발진에 의해 발생하는 EVM (error vector magnitude)이 성능 기준인 6%보다 낮게 얻어지는 것을 확인하였다. 본 연구를 통해 개발된 ICS RF 중계기를 어구 자동식별 모니터링 시스템 등의 해상 IoT 네트워크에 적용하면 서비스 영역이 늘어날 것으로 기대된다. In this research, design and fabrication of marine repeater capable to extend communication coverage in monitoring system of fishing gear automatic identification, which is one of implementation method of the real-name electric fishing gear system declared by Ministry of Oceans and Fisheries in 2016, is reported. The proposed marine repeater is fabricated in a form of RF repeater with interference cancellation system (ICS), which can cancel the oscillation due to feedback signal between service antenna and link antenna. In design process, we secure the isolation of 30 dB between service antenna and link antenna. It is confirmed that when the level of feedback signal into repeater input be lower of 15 dB than repeater gain, error vector magnitude due to oscillation can be lower than the performance criterion of 6%, from the test verification. It is expected that the service coverage will be extended by applying the developed marine ICS RF repeater into marine IoT network including monitoring system of fishing gear automatic identification.

IoT 기술을 활용한 스마트 물관리 필요성에 관한 연구

최영환(Choi Young Hwan),김영렬(Kim Yeong Real) 한국산업정보학회 2017 한국산업정보학회논문지 Vol.22 No.4

본 논문은 소비자에게 공급되는 수돗물의 공급시설(Water Supply Network)에 IoT 기술을 활용하여 소비자의 물 사용량을 원격으로 검침하고, 공급시설의 누수를 줄여서 원가를 절감하는 스마트 물관리(Smart Water Management) 기술의 적용효과를 검증하였다. SWM 실증모형은 수돗물 공급시설에 원격 누수감지센서, 스마트 미터링(Smart Metering), 초소형 멀티센서를 설치하고, 원격에서 운영현황을 실시간으로 감시하고 소비자에게 수돗물 사용량과 수질을 스마트폰 앱으로 제공하였다. 이때, 소비자가 수돗물 사용량 정보를 이용하여 수돗물을 아껴 쓰는지, 수돗물 수질정보를 이용하여 직접 음용하는지를 조사하였다. 특히, 본 연구에서는 SWM을 실증 적용함으로써 공급시설의 유수율 향상, 수돗물 음용률 향상, 소비자 민원 감소, 운영비용 절감, 수돗물 사용량 절감이 달성되는지를 검증하는데 목적이 있다. 또한 수돗물 공급시설의 IoT 센서, 운영자 모니터링 시스템, 이상발생시 탐사복구 솔루션이 융합된 하나의 SWM 모델을 수립하였으며, 관련 기술 개발을 통해 국내 물산업을 육성하고, SWM을 선진수준으로 확산하였다는데 의의가 있다고 하겠다. The Objective of this Study is to Prove the Effectiveness of a Smart Water Management(SWM) Technology. The SWM Technology can Reduce the Production Cost using Internet of Thing(IoT) Technology that Utilizes Remote Metering of Consumer’s Water usage and Reduce the Leakage of Supply Facilities. The SWM Demonstration Model Installed a Remote Water Leakage Sensor, Smart Metering and Micro Multi Sensor in Water Supply Facility, and Provided Real-Time Monitoring of the Operation Status. Consumers can be Provided the usage of Tap Water and the Water Puality through a Smart Phone Application. At this Time, we Surveyed Whether Consumers save the Tap Water or Drinking Directly using the Tap Water usage Information. Also, this Study is to Verify the Degree of Improvement of Water Supply Rates and Drinking Water Rate, and to Decrease Consumer’s Complaints, Operating Costs, and Water Consumption by the SWM Technology. It is also Established a SWM Model Combined with the IoT Sensor at Supply Facilities, operator monitoring system and explored recovery solution detected events. It means the upbringing of the domestic water industry by developing the related technologies and spreading the SWM to advanced levels.

어구 자동 식별을 위한 전자 부이의 통신 거리 및 위치 오차 검증

김성율 ( Sung-yul Kim ),임춘식 ( Choon-sik Yim ),이성렬 ( Seong-real Lee ) 한국항행학회 2021 韓國航行學會論文誌 Vol.25 No.5

전자 어구 실명제는 ‘풍요로운 어장’ 조성과 해양 환경 보호를 실행할 수 있는 주요 정책 중 하나이다. 또한 어구 자동식별 시스템은 LPWA 등의 통신과 멀티 센싱 기술을 활용하여 위 정책을 실현할 수 있는 해양 IoT 서비스 중 하나이다. 어구 자동식별 시스템은 해상에 부유하고 있는 전자 부이로부터 어구의 위치 및 유실 정보를 수집하고 어민이나 육상 관제국에게 제공한다. 어구 자동식별 시스템을 구성하는 전자 어구와 통신 장치들을 개발하였다. 본 논문에서는 전자 어구와 어선에 설치되는 무선 노드 사이의 통신 거리 측정과 전자 어구의 위치 정보 오차 측정 내용 및 결과에 대해 살펴본다. 측정 결과 통신 결과 목표치인 30 km의 2배인 62 km 거리에서 LOS 통신이 가능한 것을 확인하였고, 위치 오차는 목표치인 CEP 5 m 보다 적은 1 m의 결과를 얻었다. 따라서 본 연구를 통해 개발된 어구 자동식별 시스템의 서비스 영역과 정확도가 더욱 신장될 것으로 기대된다. The real-name electric fishing gear system is one of the important policy capable to build ‘abundant fishing ground’ and to protect marine environment. And, fishing gear automatic-identification system is one of IoT services that can implement above-mentioned policy by using communication such as low power wide area (LPWA) and multi-sensing techniques. Fishing gear automatic -identification system can gather the location data and lost/hold data from electric buoy floated in sea and can provide them to fishermen and monitoring center in land. We have developed the communication modules and electric buoy consisted of fishing gear automatic-identification system. In this paper, we report the test results of communication distance between electric buoy and wireless node installed in fish boat and location error of electric buoy. It is confirmed that line of sight (LOS) distance between electric buoy and wireless node is obtained to be 62 km, which is two times of the desired value, and location error is obtained to be CEP 1 m, which is smaller than the desired value of CEP 5 m. Therefore, it is expected that service area and accuracy of the developed fishing gear automatic-identification system is more extended.

N함몰형 대장 종양에 대한 인식과 대책

이종균,임석원,김현식,이광렬,박원갑,유정준,황도연,김건욱 대한소화기내시경학회 1999 Clinical Endoscopy Vol.19 No.3

Background/Aim: While detection and removal of polyps on the basis of the adenoma- carcinoma sequence has been a principal procedure for endoscopists, a new type of early colorectal cancer has been recognized and has become a hot issue. This new ailment is a depressed-type early colorectal cancer, which has the characteristics of rapid growth and early invasion of the submucosa. Though once considered to be mere conjecture, many researchers claim that this cancer is a de novo carcinoma despite of its rare occurrence. Recently, 4 depressed-type neoplastic lesions were presented, which signifies the importance of recognizing that this type of cancer exists and is characterized by rapid growth and early invasion of the submucosa. Methods: The 4 recently experienced depressed neoplastic lesions were reviewed and analyzed with respect to their endoscopic and clinicopathologic characteristics. The sizes of the lesions were measured in the fully inflated state of the bowel by using an endoscopic ruler. Results: The sites of predilection were the descending and sigmoid colon. All of the lesions were under 10 mm, with 75% being below 5 mm. The largest lesion was an 8-mm, well-differentiated mucosal carcinoma. The overall malignancy rate was 25%. Light redness was observed in all patients. Distortion with air transformation of the mucosal fold was also recognized in all the patients. The main treatment was endoscopic mucosal resection, which amounted to 50%. Conclusions: Depressed colorectal neoplasms are real. They can be determined by their characteristic endoscopic features, such as light redness and distortion with air transformation of the mucosal fold. Because of their characteristics of rapid growth and early invasion of the submucosa, it is important to detect and manage them in an early stage, when their sizes are below 10 mm.

해양 부이용 920 MHz 대역 안테나

최형동 ( Hyung-dong Choi ),김성율 ( Sung-yul Kim ),이성렬 ( Seong-real Lee ) 한국항행학회 2020 韓國航行學會論文誌 Vol.24 No.6

해양 IoT 서비스를 위한 장치들은 해양 환경에 강인해야 한다. 특히 바닷물 속에 부유하는 전송 장치는 바닷물의 영향을 덜 받도록 설계되어야 한다. 본 연구에서는 전자 어구 실명제 모니터링 시스템에서 어구 상태를 감시하는 부이에 내장되는 안테나를 설계하고 제작한 결과를 보이고 있다. 안테나의 주파수 대역은 920 MHz이고, 부이의 초소형과 경량화를 위해 PCB 패턴 안테나 구조로 설계 제작되었다. 시뮬레이션 결과 제안한 안테나를 내장한 부이가 바닷물 속에 잠기는 정도가 심할수록 반사 계수 증 RF 특성이 저하되지만 빔의 방사 각도는 안테나 하층부에서 점점 상층부로 옮겨가는 것을 확인하였다. 즉 바닷물의 영향을 많이 받을수록 전파 성능은 저하되지만 방사 특성은 해양 IoT 서비스 환경에 적합하다는 것을 확인하였다. 향후 RF 성능을 개선할 수 있는 안테나 구조를 변경 설계하면 제안한 안테나와 부이는 LPWA (low power wide area) 기반 IoT 네트워크 구현에 기여할 것으로 기대된다. The equipment for marine IoT service have to overcome the effect of seawater. Furthermore, the free floating transmitter in seawater will be less affected by the seawater environment. The results of the design and fabrication of antenna, which is embedded in buoy, are shown in this research. The proposed antenna is used to supervise the states of fishing gears in monitoring system for real-name system of electric fishing gear. The selected frequency band of the proposed antenna is 920 MHz, and PCB pattern type is selected for subminiature and light weight. It is confirmed that RF characteristics is more degraded, however, the radiation is gradually upward as the contact surface of buoy with seawater is more broaden through the simulation results. That is, the RF performance of the proposed antenna is more deteriorated but beam radiation characteristics is more suited the marine IoT, the seawater effect is more increased. It is expected that the proposed antenna will contribute the implementation of IoT network based on low power wide area (LPWA) when the degradation of RF performance will be settled.

LoRa 기반 어구 식별용 부이 장착 단말 및 어선용 게이트웨이

곽재민,이성렬,Kwak, Jae-Min,Lee, Seong-Real 한국정보통신학회 2018 한국정보통신학회논문지 Vol.22 No.5

해양수산부는 2016년 유실어구에 의한 피해를 최소화하기 위해 전자어구실명제 실행계획을 발표하였다. 어구의 과다사용 및 폐어구 저감을 위해 어구의 종류 및 위치, 사용자의 실명을 포함한 정보를 IoT 기반의 통신을 이용하여 어선 및 관제센터에 효율적으로 전송할 수 있는 기술이 필요하다. 본 논문에서는 전자어구실명제를 실행하기 위한 LoRa 기반의 부이 장착 단말 장치와 어선용 게이트웨이를 제안한다. SEMTECH사의 SX1276 칩 사양과 ISM 대역인 900 MHz 대역을 사용하여 1(게이트웨이):200(부이) 통신이 가능하도록 설계하고 제작하였다. 또한 전자어구실명제 실행의 기술적 제안으로써의 실증을 위해 해상 시험 결과를 분석하였다. Ministry of oceans and Fisheries declared action plan for the electric fishing gear using real name in order to prevent overusing the fishing gear and to reduce discarded fishing gear. It is needed for a technique that can efficiently transmit the information including the type and location of the fishing gear and the user's real name to the fishing boat and the control center using IoT-based communication. In this paper, we propose the buoy-launched terminal equipment and ship-launched gateway equipment based on LoRa technology for effectively executing the electric fishing gear using real name. We design and fabricate to communicate 1(gateway):200(buoy) each other under 900 MHz ISM band by using SEMTECH SX1276 chip. Also, we experiment the test on the sea and analyze the test results to prove the implementation possibility of the proposed equipments for the electric fishing gear using real name.

Static and Dynamic Behavior of Transitions between Different Railway Track Typologies

T. Real,C. Zamorano,C. Hernández,J. A. García,J. I. Real 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.4

A railway track stretch comprising three different track typologies (i.e., ballasted track, asphalt slab track and concrete slab track) has been modeled using a three-dimensional Finite Elements model, which has been calibrated and validated using real acceleration records. In this model, two different analyses have been run: a static analysis to assess the stiffness evolution and a dynamic analysis to calculate the accelerations induced by the train loads along the transition zones. These analyses have been used to assess the performance of three different techniques existing in the literature to improve the structural behavior of the track in the transition areas: the variation of the stiffness of the elastomers, the implementation of additional rails and the use of resilient mats. Results have demonstrated that these techniques perform generally better in the track vertical stiffness transition between the concrete and asphalt slab tracks while the dynamic response is not significantly altered in any scenario.