• 대한임베디드공학회논문지
• /
• 제11권2호
• /
• pp.87-95
• /
• 2016

Nonvolatile memory (NVM) is being considered as an alternative of traditional memory devices such as SRAM and DRAM, which suffer from various limitations due to the technology scaling of modern integrated circuits. Although NVMs have advantages including nonvolatility, low leakage current, and high density, their inferior write performance in terms of energy and endurance becomes a major challenge to the successful design of NVM-based memory systems. In order to overcome the aforementioned drawback of the NVM, extensive research is required to develop energy- and endurance-aware optimization techniques for NVM-based memory systems. However, researchers have experienced difficulty in finding a suitable simulation tool to prototype and evaluate new NVM optimization schemes because existing simulation tools do not consider the feature of NVM devices. In this article, we introduce a NVM-based cache simulator to support rapid prototyping and evaluation of NVM-based caches, as well as energy- and endurance-aware NVM cache optimization schemes. We demonstrate that the proposed NVM cache simulator can easily prototype PRAM cache and PRAM+STT-RAM hybrid cache as well as evaluate various write traffic reduction schemes and wear leveling schemes.

• 한국수소및신에너지학회논문집
• /
• 제25권4호
• /
• pp.405-418
• /
• 2014

Fuel cells are suitable for a power plant of a unmanned aerial vehicle (UAV) as it is not only environmentally friendly and quiet but also more efficient than an internal combustion engine. A fuel cell hybrid UAV has better performance in endurance than a fuel cell only or battery only UAV. One of the key purposes of making fuel cell hybrid UAVs is having long endurance and now maximum 26 hours of flight is possible. Because optimal design and control methods for fuel cell hybrid UAVs are absolutely needed for their long endurance we have to check the methods. The aircraft made by using application-integrated design method has less BOP mass and better performances. The optimal design and control methods are generally based on computer simulations or Hardware-In-The-Loop simulations by using dynamic models for their design and control. The Hardware-In-The-Loop simulation (HILS) is to use a hardware device like a fuel cell stack as well as a simulation program and it allows for making optimally designed applications. This paper introduce efficient methods of design, control and evaluation for the fuel cell hybrid UAVs.

• 디지털융복합연구
• /
• 제18권1호
• /
• pp.357-368
• /
• 2020

이 연구는 K3 리그 축구선수들의 시즌 중 체력 상태를 점검하기 위한 목적으로 종목 특이적인 체력측정을 시즌 초반과 후반에 실시하였다. 평가항목은 신체구성, 순발력, 민첩성, 지구력 및 등속성 하지근력 등으로 구성하였다. 측정 결과 시즌 초반과 비교하여 시즌 후반에 향상된 기능을 보여준 항목은 골격근량, 순발력, 민첩성 등이며, 신체조성, 지구력 및 등속성 하지근력은 차이점이 발견되지 못하였다. 시즌 후반부에 향상도를 보여준 항목은 시즌 중 반복적인 훈련과 시합 참여에 의한 학습효과 및 다양한 생리학적 기전에 의한 것으로 생각된다. 마지막으로 지구력과 하지근력은 별도의 특이적인 훈련을 시즌 중에 실시하지 못한 이유로 인하여 시즌 후반에 향상도를 보여주지 못한 것으로 판단된다. 이상의 결과를 종합한 결과, 선수들의 체력상태를 주기적으로 점검하는 연구를 통하여 시합기, 전이기 및 준비기에 적합한 체력 훈련프로그램의 개발 및 적용이 필요한 것으로 생각된다.

• 한국정보전자통신기술학회논문지
• /
• 제15권6호
• /
• pp.433-439
• /
• 2022

최대근지구력시간(MET, maximum endurance time)을 예측하기 위한 근피로모델은 실험적으로 측정한 MET를 이용하여 구축한 실증적 모델과 생리학적 과정을 수학적으로 표현한 이론적 모델로 나뉜다. 본 연구에서는 전완의 등척성 수축시 MET을 예측하기 위한 이론적 모델인 동적 근피로모델의 예측성 평가를 위하여 실증적 모델과 비교 및 평가하고자 한다. 실험에 참여한 피검자는 40명(남성 20, 여성 20)이며 실증적 모델인 지수모델과 거듭제곱모델 및 이론적 모델인 동적 근피로모델을 이용하여 비교하였다. 평가를 위하여 평균절대치편차(MAD, mean absolute deviation), 상관계수 및 급내상관계수를 구한 결과 동적 근피로모델과 실증적 모델들 사이에 MAD는 3.5%p 이하였으며, 상관계수는 0.93, 급내상관계수는 0.87 이상으로 전완의 등척성 수축시 MET을 예측하기 위한 이론적 모델인 동적 근피로모델이 적합함을 확인하였다.

• 한국운동역학회지
• /
• 제19권3호
• /
• pp.611-617
• /
• 2009

본 연구의 목적은 손의 부상 정도나 장애에 대한 치료의 진행 과정에 대하여 정량적인 분석을 하기 위한 것이다. 제안한 평가 항목들은 최고 악력, 악력이 가해지는 시간, 평균 악력, 악력 측정 시작부터 최고 악력까지 도달하는 순간 가속 악력, 일정한 악력 유지 시간을 측정하기 위한 동적 지구력 시간, 주어진 시간 동안 일정 악력을 유지하는 정적 지구력에 대한 변화율 등이다. 구현된 데이터베이스 시스템은 트레이닝, 기능 평가, 개인 정보 등을 기록 할 수 있도록 하였다. 또한, 악력 시스템은 60kg 범위에서 측정이 가능하도록 Load-cell을 이용한 악력 센서를 개발하였다. 제안된 시스템은 의사들이 환자의 재활 프로그램을 진행하는 데 있어 환자의 상태 이해와 해석에 편리와 효율을 제공할 것이다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 추계학술대회논문집
• /
• pp.226-229
• /
• 2008

To investigate an in-pile behavior of the newly developed DUO fuel pellet, the irradiation test will be carried out in the domestic test reactor. Irradiation test capsule for the HANARO reactor, which is a specially designed equipment used for material, irradiation and creep test, must satisfy the operational requirement on the hydraulic characteristics and structural integrity. In this study, a pressure drop, a flow-induced vibration and a short-term endurance test for the newly developed non-instrumented test capsule were carried out using FIVPET as a out-pile evaluation test. The test results show that the new test rig satisfy the HANARO operational requirement with sufficient margin.

• 한국정밀공학회지
• /
• 제24권12호
• /
• pp.74-81
• /
• 2007

This paper focuses on improvement of the reliability for endurance test to serve military automobiles. The driving loads have been measured by use of the wireless telemetry system for the drive shaft of the 4-wheel drive car. In order to analyze the transmission input torque and engine revolution of loads of the test courses and unpaved road have been made use of the revolution counting and cumulative damage by miner's rule. This paper presents the evaluated result for quantified damage about the test courses and roads.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1334-1338
• /
• 2005

A limit switch box is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or a throttle in the valve actuator. In a ship, equipments require safety and robustness because of a rough environment and a specific condition during a voyage. However, the limit switch box has been used in an indoor environment generally. This study developed a new limit switch box which can be used at an outdoor environment. This study designed the new limit switch box. The housing of the limit switch box was made by an aluminum die cast method with surface painting after anodizing or chromate coating. In order to evaluate the endurance of the housing, the endurance tests against salt water have been conducted. Experiment results showed that the proposed device provides a reliable performance against salt water.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
• /
• pp.193-196
• /
• 2006

A carbonation shortens the endurance life of RC structure. So, to lengthen endurance life of RC structure, we use some kinds of surface-finishes. Because surface-finishes have abilities such as restraint against penetration and diffusion of CO2. In this study, we wanted to know whether we can evaluate the restrain effect of each surface-finish against carbonation with using FEM analysis. After study, we found that it is possible and we also evaluate the restrain effect of any other surface-finishes against carbonation through this process.

• Tribology and Lubricants
• /
• 제27권1호
• /
• pp.25-33
• /
• 2011

Rolling contact ball bearings are utilized almost exclusively for liquid propellant rocket engine turbopump. Turbopump ball bearings are required to endure high speed and high load for a poor lubricated condition in cryogenic environment. To evaluate bearing heat generation performance, friction torque is investigated as a function of rotation speed, bearing load and cooling flow rate through an experimental study using water coolants. Radial and axial loads are simultaneously applied to the test bearing by gas pressurized cylinder rod. Endurance performance of bearing has been also verified under the bearing required load for operating condition during total accumulated test time 2,100 sec.