• Smart Structures and Systems
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• 제16권4호
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• pp.743-758
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• 2015

This paper presents an advanced life cycle cost (LCC) analysis of a ground source heat pump (GSHP) system and suggests a smart operation mode with a thermal performance test (TPT) and an energy pile system constructed on the site of the Incheon International Airport (IIA). First, an economic analysis of the GSHP system was conducted for the second passenger terminal of the IIA considering actual influencing factors such as government support and the residual value of the equipment. The analysis results showed that the economic efficiency of the GSHP system could be increased owing to several influential factors. Second, a multiple regression analysis was conducted using different independent variables in order to analyze the influence indices with regard to the LCC results. Every independent index, in this case the initial construction cost, lifespan of the equipment, discount rate and the amount of price inflation can affect the LCC results. Third, a GSHP system using an energy pile was installed on the site of the construction laboratory institute of the IIA. TPTs of W-shape and spiral-coil-type GHEs were conducted in continuous and intermittent operation modes, respectively, prior to system operation of the energy pile. A cooling GSHP system in the energy pile was operated in both the continuous and intermittent modes, and the LCC was calculated. Furthermore, the smart operation mode and LCC were analyzed considering the application of a thermal storage tank.

• 대한임베디드공학회논문지
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• 제12권3호
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• pp.121-130
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• 2017

NAND flash memory has advantages of non-volatility, little power consumption and fast access time. However, it suffers from inability that does not provide to update-in-place and the erase cycle is limited. Moreover, the unit of read/write operation is a page and the unit of erase operation is a block. Therefore, erase operation is slower than other operations. The AGC, the proposed garbage collection policy focuses on not only garbage collection time reduction for real-time guarantee but also wear-leveling for a flash memory lifetime. In order to achieve above goals, we define three garbage collection operating modes: Fast Mode, Smart Mode, and Wear-leveling Mode. The proposed policy decides the garbage collection mode depending on system CPU usage rate. Fast Mode selects the dirtiest block as victim block to minimize the erase operation time. However, Smart Mode selects the victim block by reflecting the invalid page number and block erase count to minimizing the erase operation time and deviation of block erase count. Wear-leveling Mode operates similar to Smart Mode and it makes groups and relocates the pages which has the similar update time. We implemented the proposed policy and measured the performance compare with the existing policies. Simulation results show that the proposed policy performs better than Cost-benefit policy with the 55% reduction in the operation time. Also, it performs better than Greedy policy with the 87% reduction in the deviation of erase count. Most of all, the proposed policy works adaptively according to the CPU usage rate, and guarantees the real-time performance of the system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3359-3364
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• 2007

The smart energy system is the integrated power system in which the power components including central station generation, distributed generation, renewable power generation, energy storage, and communications and controls are complexly connected with each other. In smart energy system, it is very important how to configure the diverse power generations and how to determine the operation mode of the chosen components with economic feasibility. In this study, we introduce the optimal planning method based on both economic feasibility and load profiles and its applications for the smart energy system in apartment. This method was considered very useful to determine the configuration and to decide the optimal operation mode of the smart energy system.

• 한국태양에너지학회 논문집
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• 제34권4호
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• pp.1-7
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• 2014

The microgrid system is the combination of photovoltaic(PV) array, load, and battery energy storage system. The control strategies were defined as multi-modes of operation, including rest operation without use of battery, power charging, and power discharging, which enables grid connected mode or islanded mode. Photovoltaic power is a problem of the uniformity of power quality because the power generated from solar light is very sensitive to variation of insolation and duration of sunshine. As a solution to the above problem, energy storage system(ESS) is considered generally. There fore, in this study, we did basic research activities about optimization method of the amount of energy used, using a smart microgrid test-bed constructed in building. First, we analyzed the daily, monthly and period energy pattern amount of power energy used, and analyzed PV power generation level which is built on the roof. Utilizing building energy pattern analysis data, we was studied an efficient method of employing the ESS about building power consumption pattern and PV generation.

• IEIE Transactions on Smart Processing and Computing
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• 제5권4호
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• pp.235-242
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• 2016

The emerging High-Efficiency Video Coding (HEVC) standard attempts to improve coding efficiency by a factor of two over H.264/Advanced Video Coding (AVC) at the expense of an increase in computational complexity. Mode decision with motion estimation (ME) is still one of the most time-consuming computations in HEVC, as it is with H.264/AVC. Thus, fast mode decisions are not only an important issue to be researched, but also an urgent one. Several schemes for fast mode decisions have been presented in reference software and in other studies. However, the conventional hierarchical mode decision can be useless when block-level parallelism is exploited. This paper proposes operation-level exploration that offers more chances for early termination. An early termination condition is checked between integer and fractional MEs and between the parts of one partition type. The fast decision points of the proposed algorithm do not overlap those in previous works. Thus, the proposed algorithms are easily used with other fast algorithms, and consequently, independent speed-up is possible.

• Journal of Advanced Marine Engineering and Technology
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• 제36권1호
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• pp.141-148
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• 2012

The power system of leisure ship has a character of stand-alone type, so it continuously checks the usable power. Especially, the leisure ship using renewable energy needs to adjust the power consumption of loads according to the usable power. Also, the important loads of leisure ship are different by operation mode. However, current power management system doesnot consider such character. This paper studied load management system of the SPMS(Smart Power Management System) and composed using the smart plug. The SPMS controls the loads depending on a user's pattern and character through variable priority number control. This control algorithm was verified through simulation of assumed user and situation using LabVIEW.

• 한국추진공학회지
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• 제12권4호
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• pp.42-47
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• 2008

스마트무인기의 출력제어계통은 터보프롭 항공기와 유사한 피치 가버닝 개념으로 조종사가 엔진출력을 직접 조절하고 제어기는 프로펠러의 회전속도를 일정하게 유지하는 방식을 사용한다. PW206C 엔진은 회전익 항공기에 맞게 개발된 전자식엔진제어기를 갖춘 터보축 엔진으로 스마트무인기에서 요구되는 엔진제어개념과는 맞지 않는다. 따라서 엔진 출력을 전기식 작동기를 엔진의 출력조절레버에 연결하여 조절하는 수동방식을 사용한다. 본 논문에서는 엔진성능계산프로그램을 사용하여 엔진출력축속도, 비행고도 및 비행속도변화에 대한 엔진성능을 계산하여 각 비행조건에서의 출력조절레버각의 작동범위를 예측한다.

• 한국인터넷방송통신학회논문지
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• 제10권3호
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• pp.35-41
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• 2010

본 논문에서는 안드로이드 기반의 서비스 로봇 제어를 위한 유비쿼터스 인터페이스를 제안한다. 로봇의 호스트 컴퓨터인 서버에서 전방의 영상, 지도 정보와 로봇의 현재 위치를 표현한 그래픽, 및 로봇의 모션에 대한 그래픽 영상을 안드로이드 클라이언트에 전달하고, 안드로이드는 그 결과를 화면상에 표현한다. 안드로이드는 로봇을 원격제어하거나 목표위치 지정 및 로봇의 동작을 제어하기 위한 정보를 버튼으로 표현하고 그 정보를 서버에 전달하여 안드로이드 기반의 유비쿼터스 인터페이스가 가능하도록 한다. 로봇의 이동과 동작을 제한된 크기의 스마트폰 화면에서 제어하기 위해 원격이동 모드, 자동이동 모드 및 원격조작 모드를 구현한다. 실험에서는 모토로이 안드로이드 폰을 이용한 인터페이스를 구현하여 실제 서비스 로봇 제어에 적용한 결과를 통해 제안한 인터페이스가 로봇 제어를 위한 유비쿼터스 인터페이스로서 응용될 수 있음을 보여준다.

• 항공우주시스템공학회지
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• 제18권1호
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• pp.88-98
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• 2024

본 논문에서는 디지털 지형 고도 데이터를 이용한 자동 지형 추종 시뮬레이터를 제안하였다. ATF Simulator는 Flight Simulator, Radar Simulator, TFC Simulator로 구성하였다. 지형 추종에 필요한 지형 정보로 디지털 지형 고도 데이터와 디지털 지형 고도 데이터를 이용하여 생성한 레이다 스캔 데이터를 활용하였다. ATF Simulator는 디지털 지형 고도 데이터를 이용하는 Passive mode, 레이다 스캔 데이터를 이용하는 Active mode, 두 가지 모두 이용하는 Hybrid mode로 세 가지 운용모드를 제공한다. LabVIEW 개발 환경과 MATLAB App Designer 개발 환경을 통해 지형 추종 시스템 개발에 소요되는 비용 및 시간을 줄일 수 있는 ATF Simulator를 개발하였으며 기능요구사항을 충족하는지 확인하여 검증하였다.

• 시스템엔지니어링학술지
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• 제1권2호
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• pp.43-48
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• 2005

This paper describes the results of applying States and Modes Analysis, one of the requirements analysis techniques, to the development requirements of flight control software for Smart UAV. State/mode table enabled us to investigate various operation and design concepts, and as a result essential requirements for flight control software were established without omitting necessary requirements. Through the use of scenario-specific state transition diagrams, dynamic behaviours and control/response interfaces between each state and mode could been clearly identified, which made it possible to establish requirements related to dynamic behaviours of states and modes which are essential to the design of flight control software.