• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권2호
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• pp.468-479
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• 2012

Recent advances in wireless communications and electronics has enabled the development of machine-to-machine (M2M) communications. This communication paradigm has been expected as an automated control and report solution for smart grid. The smart grid enables customers and operators to utilize the collected usage information from a large number of meters with transceivers for efficiency and safety. In this paper, we introduce architecture, requirements and challenges of M2M communications for smart grid. We extract technical issues that should be resolved in M2M communications to support the smart grid via third-generation partnership project (3GPP) cellular networks. We then present the current state of the art of research results to deal with such issues. Finally, we outline the open research issues.

• 대한기계학회논문집A
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• 제41권6호
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• pp.533-541
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• 2017

최근 컴퓨터 및 통신기술의 적극적인 결합에 따른 생산 시스템의 자동화 및 지능화가 급속하게 진행됨에 따라, 자동화 시스템의 핵심 요소 중 하나인 스마트 센서를 내장한 필드 장치들의 수도 급격하게 증가하고 있으며 이들을 통합 관리할 필요성도 높아지고 있다. 본 논문에서는 엔코더의 위치 데이터 센싱 기능과 CANopen 프로토콜을 결합한 스마트 엔코더 구조를 제안하고, 복수 개의 엔코더를 CAN 네트워크를 통해 동시에 관리, 모니터링할 수 있는 시스템 구조를 설계, 구현하였다. 구현한 시스템의 성능과 기능적 동작은 상용 엔코더와의 비교 실험과 CANopen 호환성 테스트를 이용하여 검증하였다.

• 대한임베디드공학회논문지
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• 제8권5호
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• pp.235-242
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• 2013

Recently, the number of automotive electrical and electronic system has been increased because the requirements for the convenience and safety of the drivers and passengers are raised. In most cases, the data for controlling the various sensors and automotive electrical and electronic system used in runtime should be stored on the internal or external non-volatile memory of the ECU(Electronic Control Units). However, the non-volatile memory has a constraint with write limitation due to the hardware characteristics. The limitation causes fatal accidents or unexpected results if the non-volatile memory is not managed. In this paper, we propose a management scheme for using non-volatile memory to prolong the writing times based on AUTOSAR(AUTOmotive Open System Architecture) platform. Our proposal is implemented on the CDD(Complex Device Driver) and uses an algorithm which swaps a frequently modified block for a least modified block. Through the development of the prototype, the proposed scheme extends the lifetime of non-volatile memory about 1.08 to 2.48 times than simply using the AUTOSAR standard.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2014년도 추계학술발표대회
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• pp.703-706
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• 2014

AUOTSAR(Automotive Open system Architecture)는 자동차 ECU(Electronic Control Unit) 에 내장되는 소프트웨어에 대한 표준 구조로서, ECU 소프트웨어의 품질 향상은 물론, 개발 및 관리 비용의 절감에 기여하는 등 많은 장점을 갖는다. AUTOSAR 의 이런 장점 때문에 많은 자동차 회사들이 ECU 소프트웨어에 AUTOSAR 적용을 추진하고 있다. 이에 따라 기존 레거시 ECU 소프트웨어 시스템을 AUTOSAR 표준에 맞는 ECU 소프트웨어 시스템으로 변환하는 방법에 대한 관심도 높아지고 있다. 그 이유는 이미 많은 ECU 레거시 소프트웨어 시스템들이 개발되어 사용되고 있으며, 이들에게는 이미 기능 및 안정성 검증을 위하여 많은 시간과 비용이 투자하여 되어 있다. 따라서 ECU 소프트웨어 시스템에 AUTOSAR 를 적용하는 경우 기존의 레거시 소프트웨어 시스템을 재사용할 수 있으면 생산성 및 품질 면에서 많은 장점을 갖는다. 본 연구에서는 C 언어로 작성된 기존의 ECU 소프트웨어 시스템을 AUTOSAR 플랫폼에서 재사용할 수 있도록 하기 위하여, 기존의 레거시 ECU 소프트웨어 시스템을 AUTOSAR 플랫폼으로 마이그레이션하는 방법에 대하여 연구하였다. 마이그레이션 과정은 크게 두 단계로 나누어 지는데, 이는 레거시 소프트웨어 시스템을 분석하여 마이그레이션이 가능하도록 기능별로 분해하는 것과, 분해된 구성 요소들을 AUTOSAR 플랫폼에 맞는 구조로 재구성하는 과정이다. 본 논문에서는 이중 첫 번째 과정인 레거시 소프트웨어 시스템의 분석 및 기능별 분해 방법을 제시하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권2호
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• pp.421-441
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• 2021

Fruit detection in orchards is one of the most crucial tasks for designing the visual system of an automated harvesting robot. It is the first and foremost tool employed for tasks such as sorting, grading, harvesting, disease control, and yield estimation, etc. Efficient visual systems are crucial for designing an automated robot. However, conventional fruit detection methods always a trade-off with accuracy, real-time response, and extensibility. Therefore, an improved method is proposed based on coarse-to-fine multitask cascaded convolutional networks (MTCNN) with three aspects to enable the practical application. First, the architecture of Fruit-MTCNN was improved to increase its power to discriminate between objects and their backgrounds. Then, with a few manual labels and operations, synthetic images and labels were generated to increase the diversity and the number of image samples. Further, through the online hard example mining (OHEM) strategy during training, the detector retrained hard examples. Finally, the improved detector was tested for its performance that proved superior in predicted accuracy and retaining good performances on portability with the low time cost. Based on performance, it was concluded that the detector could be applied practically in the actual orchard environment.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.121-128
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• 2021

In order to design a real time big data collection and analysis system of manufacturing data in a smart factory, it is important to establish an appropriate wired/wireless communication system and protocol. This paper introduces the latest communication protocol, OPC-UA (Open Platform Communication Unified Architecture) based client/server function, applied user interface technology to configure a network for real-time data collection through IoT Integration. Then, Database is designed in MES (Manufacturing Execution System) based on the analysis table that reflects the user's requirements among the data extracted from the new cutting process automation process, bush inner diameter indentation measurement system and tool monitoring/inspection system. In summary, big data analysis system introduced in this paper performs SPC (statistical Process Control) analysis and visualization analysis with interface of OPC-UA-based wired/wireless communication. Through AI learning modeling with XGBoost (eXtream Gradient Boosting) and LR (Linear Regression) algorithm, quality and visualization analysis is carried out the storage and connection to the cloud.

• 전기전자학회논문지
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• 제24권4호
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• pp.1172-1175
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• 2020

차량에 사용되는 ECU에는 CPU 코어, 차량통신 콘트롤러, 메모리 인터페이스, 센서 인터페이스, I/O 인터페이스 등이 집적되어 있다. 현재 사용되는 차량용 ECU는 대부분 자사만의 독점적 프로세서 아키텍쳐로 개발하였으나, 최근 자율주행자동차 및 커넥티드카에서 소프트웨어 범용성을 위해 ARM, RISC-V와 같은 표준 프로세서를 기반으로 한 차량용 ECU의 수요가 급증하고 있다. 본 논문에서는 명령어 집합이 무료로 공개된 RISC-V를 기반으로 하여 주차 보조 시스템에 사용하기 위한 차량용 ECU를 설계하였다. 개발된 ECU는 32b RISC-V CPU 코어, CAN, LIN 등의 IVN 콘트롤러, ROM, SRAM 등의 메모리 인터페이스, SPI, UART, I2C 등의 I/O 인터페이스를 내장하였다. 65nm CMOS 공정에서 구현한 결과는 동작 주파수 50MHz, 면적 0.37㎟, 게이트 수 55,310개였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.306-320
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• 2021

To ensure safe port operations around the world, it is important to solve mooring problems. In particular, the many ports that face open seas have difficulties with long-period waves. As a countermeasure, the installation of a breakwater is proposed for mooring safety. However, this often cannot be put into practice because of financial issues. Instead, port terminals control berthing schedules with weather forecasting. However, mooring problems remain unsolved, because of inaccurate wave forecasting. To quantify the current situation, numerical simulations are presented with ship motions, fender deflections, and rope tensions. In addition, novel simulations for mooring ropes are proposed considering tension, friction, bending fatigue, and temperature. With this novel simulation, the optimal mooring method in terms of safety and economic efficiency was confirmed. In terms of safety, the optimal mooring method is verified to minimize dangerous mooring situations. Moreover, the optimal mooring method shows economic benefits and efficiency. It can help to reinforce the safety of port terminals and improve the efficiency of port operations.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권4호
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• pp.491-498
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• 2018

The cost evaluation for voyage route planning in an ice-covered sea is one of the major topics among ship owners. Information of the ice properties, such as ice type, concentration of ice, ice thickness, strength of ice, and speed-power relation under ice conditions are important for determining the optimal route in ice and low operational cost perspective. To determine achievable speed at any designated pack ice condition, a model test of resistance, self-propulsion, and overload test in ice and ice-free water were carried out in a KRISO ice tank and towing tank. The available net thrust for ice and an estimation of the ice resistance under any pack ice condition were also performed by I-RES. The in-house code called 'I-RES', which is an ice resistance estimation tool that applies an empirical formula, was modified for the pack ice module in this study. Careful observations of underwater videos of the ice model test made it possible to understand the physical phenomena of underneath of the hull bottom surface and determine the coverage of buoyancy. The clearing resistance of ice can be calculated by subtracting the buoyance and open water resistance form the pre-sawn ice resistance. The model test results in pack ice were compared with the calculation results to obtain a correlation factor among the pack ice resistance, ice concentration, and ship speed. The resulting correlation factors were applied to the calculation results to determine the pack ice resistance under any pack ice condition. The pack ice resistance under the arbitrary pack ice condition could be estimated because software I-RES could control all the ice properties. The available net thrust in ice, which is the over thrust that overcomes the pack ice resistance, will change the speed of a ship according to the bollard pull test results and thruster characteristics (engine & propulsion combination). The attainable speed at a certain ice concentration of pack ice was determined using the interpolation method. This paper reports a procedure to determine the attainable speed in pack ice and the sample calculation using the Araon vessel was performed to confirm the entire process. A more detailed description of the determination of the attainable speed is described. The attainable speed in 1.0 m, 90% pack ice and 540 kPa strength was 13.3 knots.

• KIEAE Journal
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• 제17권3호
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• pp.119-124
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• 2017

Purpose: Groundwater heat pump (GWHP) system has high coefficient of performance than conventional air-source heat pump system and closed-loop type geothermal system. However, there is problem in long-term operation that groundwater raise at the diffusion well and reduced at the supply well. Therefore, it is necessary to accurately predict the groundwater flow, groundwater movement and control the groundwater level in the wells. In this research, in consideration of hydrogeological characteristic, groundwater level and groundwater movement were conducted analysis in order to develop the optimal design method of the two-well system using the pairing pipe. Method: For the optimum design of the two-well system, this research focused on the design method of the pairing pipe in the simulation model. Especially, in order to control the groundwater level in wells, pairing pipe between the supply well and diffusion well was developed and the groundwater level during the system operation was analyzed by the numerical simulation. Result: As the result of simulation, the groundwater level increased to -2.65m even in the condition of low hydraulic conductivity and high pumping flow rate. Consequently, it was found that the developed system can be operated stably.