• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.464-467
• /
• 2000

In this paper we introduce the network based multi-motors control system using CAN(Controller Area Network) The traditional multi-motors control system has many problems in the view of reliability and economy because of the amount and complexity of wiring noise and maintenance problems etc, These problems are serious especially when the motor controllers are separated widely CAN is generally applied in car networking in order to reduce the complexity of the related wiring harnesses. These traditional CAN application techniques are modified to achieve the real time communication for the multi-motor control system. And also the position synchronization technique is developed and the proposed methods are verified experimentally.

• 한국구조물진단유지관리공학회 논문집
• /
• 제11권1호
• /
• pp.103-112
• /
• 2007

구조 재료와 시공기술의 발달로 구조물은 높고 길게 설계할 수 있게 되었으나, 그에 따른 진동문제와 사용성에 관한 문제가 발생하였고, 구조물의 과다한 변위는 구조물에 심각한 손상을 발생시켰다. 이러한 구조물의 진동 문제를 해결하기 위하여 본 논문에서는 구조물의 상태벡터와 제어력만으로 구성된 훈련패턴을 기본으로 하여 인공신경망이론과 확률신경망이론을 사용하여 구조물의 진동을 능동제어하는 방법을 제안하였다. 구조물의 제어를 위해 LQR 제어알고리즘을 이용하여 구조물의 상태벡터와 제어력을 구한 후, 상태벡터를 입력으로 제어력을 출력으로 하는 인공신경망과 확률신경망의 훈련패턴을 구성하였다. 제안된 방법을 사용하여 Northridge 지진하중을 받는 3층 빌딩구조물을 제어하였고, 제안된 인공신경망과 확률신경망의 제어 결과를 비교하였다.

• 환경영향평가
• /
• 제16권3호
• /
• pp.187-194
• /
• 2007

It started road constructions around river in 1990s. These maintenances concentrate on city river. Because river lives no living things and men don't come near there. But in spite of these river environment go to rack, river maintenances still keep on using preexistence method since 1990s. Only a part of city river environment maintenances consider environmental ability of passive river, river maintenance of a purpose of flood control still don't consider in the concrete. Because propulsion device that consider environment ability of passive river and possible application techniques don't complete. In accordance, A natural river maintenance needs absolutly a series of river projects. Because a natural river maintenance prevents a damage of environment ability. This study is to assume the flood really happened and to carry out the flood damage simulation needed in overflow simulation about the inundated zone. Also, This study examine unstable part about the hydraulic characteristic as velocities, stream power, shear, hydraulic depth, flow area in basin. And this study applied the HEC-RAS(river analysis system) model to predict flood overflow in youngsan river basin. Project flood is used the return period 100 year and inputed data that was calculated in intensity figures of illumination.

• 반도체디스플레이기술학회지
• /
• 제18권4호
• /
• pp.87-91
• /
• 2019

The diagnosis of the failure for the existing electrical facilities was based on regular preventive maintenance, but this preventive maintenance was limited in preventing a lot of cost loss and sudden system failure. To overcome these shortcomings, fault prediction and diagnostic techniques are critical to increasing system reliability by monitoring electrical installations in real time and detecting abnormal conditions in the facility early. As the performance and quality deterioration problem occurs frequently due to the increase in the number of users of the motor pump, the purpose is to build an intelligent control system that can control the motor pump to maximize the performance and to improve the quality and reliability. To this end, a vibration sensor, temperature sensor, pressure sensor, and low water level sensor are used to detect vibrations, temperatures, pressures, and low water levels that can occur in the motor pump, and to build a system that can identify and diagnose information to users in real time.

• 한국구조물진단유지관리공학회 논문집
• /
• 제26권4호
• /
• pp.40-47
• /
• 2022

이 연구의 목적은 철근콘크리트 벽체의 내력, 변형 및 균열진전에 대한 개구부 모서리의 사인장 균열 제어를 위한 다양한 보강방법들이 효율성을 평가하는 것이다. 개구부 모서리의 사인장 균열제어 보강방법으로서 이 연구에서 제안한 균열제어 띠, 기존의 경사보강근 배근방법, 그리고 응력분산곡면판을 선택하였다. 균열제어 띠에서는 균열치유 기능성이 부여된 것도 함께 고려하였다. 개구부 주위의 체적변화 및 균열 폭 진전을 평가하기 위하여 개구부 모서리에서 사인장 균열 유도를 위한 축소 벽체 실험을 수행하였다. 실험결과 균열제어 띠는 경사보강근 및 응력분산곡면판에 비해 개구부 주위의 체적변화 감소 및 개구부 모서리 균열 폭 제어에 효율적이었다. 균열 치유 기능이 포함된 균열제어 띠는 사전 실험에서 발생한 균열들을 치유하면서 축소 벽체의 내력 향상 및 균열 폭 감소에 가장 좋은 성능을 보였다.

• Smart Structures and Systems
• /
• 제17권1호
• /
• pp.135-147
• /
• 2016

This paper describes a smart structural system, which uses smart materials for real-time monitoring and active control of bolted-joints in steel structures. The goal of this research is to reduce the possibility of failure and the cost of maintenance of steel structures such as bridges, electricity pylons, steel lattice towers and so on. The concept of the smart structural system combines impedance based health monitoring techniques with a shape memory alloy (SMA) washer to restore the tension of the loosened bolt. The impedance-based structural health monitoring (SHM) techniques were used to detect loosened bolts in bolted-joints. By comparing electrical impedance signatures measured from a potentially damage structure with baseline data obtained from the pristine structure, the bolt loosening damage could be detected. An outlier analysis, using generalized extreme value (GEV) distribution, providing optimal decision boundaries, has been carried out for more systematic damage detection. Once the loosening damage was detected in the bolted joint, the external heater, which was bonded to the SMA washer, actuated the washer. Then, the heated SMA washer expanded axially and adjusted the bolt tension to restore the lost torque. Additionally, temperature variation due to the heater was compensated by applying the effective frequency shift (EFS) algorithm to improve the performance of the diagnostic results. An experimental study was conducted by integrating the piezoelectric material based structural health monitoring and the SMA-based active control function on a bolted joint, after which the performance of the smart 'self-monitoring and self-healing bolted joint system' was demonstrated.

• 한국환경복원기술학회지
• /
• 제4권4호
• /
• pp.72-81
• /
• 2001

This study is aimed to review the previous research accomplishments with analysis of problems and to suggest the counter plan for the watershed management and the ongoing research strategy. Phytoremediation provides a cost-effective techniques having a merit of low investment and maintenance cost. It could be one of the best techniques, which is an alternative plan to overcome economical situation and lack of experts in our country. In forest watershed affected by waste water and heavy metal pollutants should be controlled by vegetative remediation system, but the disposal techniques of harvested plant materials should be developed. Also, high degree areas of natural vegetation as a key model to recover the vegetation should be well conserved. It is important to restore forest continuity between upper stream and lower stream basin with the restoration of damaged in forest watershed. It is established to integrated protection system for land use and management plan and to natural environment evaluation methods affected by projects such as erosion control and developments in stream and forest. In addition, I suggest the continuous environmental monitoring system to treat the pollutions concerned.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.467-470
• /
• 2009

Variable loads along the drive-train are attributed to frequent failures of gears, bearings, and other components. Wind parameters cannot be controlled and therefore any turbine load-reducing remedies must be established based on proper insights into the wind-turbine interactions. A novel control concept to performance optimization of wind turbines is presented. This proposed concept is based on analysis of the turbine status reflected in the SCADA data. Modern computational techniques are used to optimize performance of a wind turbine from tree basic perspectives: drive-train, power output, and power quality. The proposed approach demonstrates that gains in the metrics representing the three perspectives and the corresponding control goals can be significantly improved for any wind turbine. The solution is applicable different turbine types operating in different wind regimes, e.g., winds of different speeds and variability. Simple and transparent parameters allow an operator to determine a balance between the operations and maintenance, technical, business objectives. The proposed modeling framework was embedded in software. The software tool has been tested on the data collected from 1.5 MW wind turbines.

• 전자공학회논문지A
• /
• 제33A권5호
• /
• pp.10-23
• /
• 1996

In this paper, the reverse link performance evaluation with synchronous CDMA is analyzed in the PCS system, which is the schem based on proposed method of KMT-PCS to increase the capacitance of cellular CDMA system. We make the baseband system model of CDMA reverse link, and then analyze system performance and subsystem techniques considering effect of channel and power control that are improtant factor influencing system performance in the PCS system. Based on this result, the paper presents primary technique analyses required at synchronous reverse link proposed by the KMT, which compose of initial synchronization range in initial synchronization step and control signal period in the synchronization maintenance step.

• 전기학회논문지P
• /
• 제59권3호
• /
• pp.288-292
• /
• 2010

Recently, in energy storage system, the EDLC is paid attention as a new environmentally friendly energy storage element. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. But the EDLC must have a each charge-discharge controller to effectively control, an energy design method circuit to use effectively energy, and several compensation techniques to control a optimal operating. In this respect, this study suggests major parameters to effectively represent the characteristics of EDLC, the measurement methods of those parameters have been investigated with experiments, and the interpretation about the buck/boost DC/DC converter for the operation of EDLC.