• 한국군사과학기술학회지
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• 제16권6호
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• pp.745-751
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• 2013

In naval gun firing, firing accuracy comes from the combination of each component's accuracy in CFCS (Command and Fire Control System) like tracking sensors and gun. Generally, battery alignment is done to correct the error between gun and tracking sensor by using boresight telescope on harbor and sea. But normally, the battery alignment can compensate only the static alignment error and ignore dynamic alignment error which is caused by own ship movement. There was no research on this dynamic alignment error until now. We propose a new way to analyze dynamic arrangement error by using image of boresight telescope. In case of the dynamic alignment error was due to time delay of own ship attitude information, we propose the way to compensate it.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.349-352
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• 1994

An object recognition and restoration using ultrasound sensors and neural networks are presented. The planar arrangement of the sensor is used to reduce the interference effects between sensors. The SOFM(Self-Organizing Feature Map) Neural Network and SCL(Simple Competitive Learning) method are learned with the acquired data. Lab experiments were performed that the object can be recognized ed the resolutions of the object can be enhanced by using the small number of the ultrasound array and neural networks.

• 한국정밀공학회지
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• 제14권8호
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• pp.146-154
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• 1997

Solenoid-folw control type ABS is used with a 'dump and reapply' pressure control arrangement instead of using 2/2 (normal open/close) solenoid valves in convensional systems(sol. -sol. control type), a flow control valve is used which replaces the (no) inlet valve. The flow control valve controls fluid flow providing a nearly constant reapply rate( .theta. ) after the dump plase of ABS operation. In this study, to investigate a characteristics of brake pressure by PWM control, test rig was consisted of ABS hydraulic modulator, digital controller, pneumatic power supply and brake master cylinder. For comparison with experi- mental results, system modelling and computer simulation were performed. As a result, experiment results showed fairly agreement with the simulation. Also, it is shown that the pressure gradient (tan .theta. ) is affected by pressure, frequency, duty ratio and expressed with an exponential funtion.

• 전자공학회논문지
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• 제51권4호
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• pp.181-190
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• 2014

수중음향렌즈 시스템은 해저를 탐사하여 고해상도의 영상을 얻어내는 시스템의 하나로 음향렌즈를 이용하여 빔을 형성한다. 음향렌즈를 이용하여 빔을 형성함으로써 복잡도를 낮추고 구동전력을 절감시킨다. 음향렌즈로부터 들어오는 빔을 배열센서로 수신하려면 음향렌즈의 빔패턴을 분석하여 센서간격을 설정하는 문제를 해결해야 한다. 여기서 SIR (Signal to Interference Ratio)을 사용하여 센서간격과 빔패턴과 영상 품질과의 관계를 분석한다. 빔패턴의 모양에 따라 SIR은 변하므로 대체로 센서간격이 넓으면 사이드로브의 영향이 감소하므로 SIR이 개선된다. 사이드로브의 크기가 크면 전반적으로 SIR이 악화된다. Apodization 함수에 따라 빔패턴의 메인로브의 폭과 모양과 사이드로브의 모양과 준위가 바뀐다. 따라서 적절한 apodization 함수를 적용하여 SIR을 개선한다. 본 논문에서 예시된 빔패턴의 경우 센서간격이 13mm에서 SIR이 0-10dB로 안정이 되지만, 그 값이 높지 않다. 따라서 Chebyshev 함수를 적용하여 37mm 이상의 구간에서 80dB의 SIR을 얻는다. 센서간격이 더 작은 경우는 Hann 함수나 triangular 함수가 좋은 성능을 나타냈다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1612-1616
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• 2005

In this paper, a Home Mess-Cleanup Robot(HMR), which has a practical function of the automatic mess-cleanup, is developed. The vacuum-cleaner had made the burden of house chore lighten but the operation labour of a vacuum-cleaner had been so severe. Recently, the cleaning robot was producted to perfectly solve the cleaning labour of a house but it also was not successful because it still had a problem of mess-cleaning, which was the clean-up of big trash and the arrangement of newspapers, clothes, etc. The cleaning robot is to just vacuum dust and small trash but has no function to arrange and take away before the automatic vacuum-cleaning. For this reason, the market for the cleaning robot is not yet built up. So, we need a design method and technological algorithm of new automatic machine to solve the problem of mess-cleanup in house. It needs functions of agile automatic navigation, novel manipulation system for mess-cleanup. The automatic navigation system has to be controlled for the full scanning of living room, to recognize the absolute position and orientation of the self, the precise tracking of the desired path, and to distinguish the mess object to clean-up from obstacle object to just avoid. The manipulator, which is not needed in the vacuum-cleaning robot, must have the functions, how to distinguish big trash to clean from mess objects to arrange, how to grasp in according to the form of mess objects, how to move to the destination in according to mess objects and arrange them. We use the RFID system to solve the problems in this paper and propose the reading algorithm of RFID tags installed in indoor objects and environments. Then, it should be an intelligent system so that the mess cleaning task can be autonomously performed in a wide variety of situations and environments. It needs to also has the entertainment functions for the good communication between the human and HMR. Finally, the good performance of the designed HMR is confirmed through the results of the mess clean-up and arrangement.

• 한국비블리아학회지
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• 제6권1호
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• pp.179-213
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• 1984

The history of recording and conserving for maintenance the human's memory from ancient times to modern's has brought about a lot of changing process of the recorded information media with developing in culture, and each society has made important recorded materials in his library as essentially the social apparatus. But most of them that were damaged by factors of the natural disaster, humidity, temperature, light, fungi and insects in the library, and were resulted in deterioration and losing the numerous materials. For removing the inevitable phases repeated, there are studying for counterplan of the fundamental environment factors about preservation, restoration and chemical research of materials in advanced countries, but I get a few researches about protecting the cultural properties. Therefore I research the survey of the actual conditions on 72 university libraries centering around them, and then I have researched the collection rate 81 percent, 58 university libraries. (local : 35, in seoul : 23) As the result of this research, I propose the model of the environment factors of conserving the library materials. 1) To apply the equipment of processing the radiant energy to the new construction and buildings. 2) To remove factors that occur fungi and insects by facilities being controlled relative humility, temperature, and to equip the ventilation arrangement in the library. 3) To shelve all acquired and bound materials after proceeding the vacuum fumigator. 4) Those who want to enter into the library stack were surely taken in sterilzing their hands and shoes, and must put on the gown. 5) To use the vacuum dusting thing (machine) for removing the dust without spreading out the floor of the library at any time. 6) To set up the gas automatic fire extinguisher worked by smoke sensor. 7) To assist the research into the preservation, natures and environment of recorded materials, and to supply financial funds for librarian. 8) To hold regularly the workshop be able to educate the methods of preservation materials by the constant system. (Library Association) 9) To add to responsibilities on certification of preservation materials for librarian. 10) To hold the constant committee system in each library. 11) To keep up with the ideal environment (humidity, temperature, light, ventilation, etc.) of preservation materials in the arrangement room, and to put on the gown.

• 한국전기전자재료학회논문지
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• 제35권6호
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• pp.523-546
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• 2022

Morphotropic phase boundary (MPB), which is a special boundary that separates two or multiple different phases in the phase diagram of some ferroelectric ceramics, is an important concept in identifying physics that includes piezoelectric responses. MPB, which had not been discovered in organic materials until recently, was discovered in poly(vinylidene fluoride-co-trifluoroethylene (P(VDF-TrFE)), resulting from a molecular approach. The piezoelectric coefficient of P(VDF-TrFE) in this MPB region was achieved up to -63.5 pC N^-1, which is about two times as large as the conventional value of -30 pC N^-1 of P(VDF-TrFE). An order-disorder arrangement greatly affects the rise of the piezoelectric effect and the ferroelectric, paraelectric and relaxor ferroelectric of P(VDF-TrFE), so the arrangement and shape of the polymer chain is important. In this review, we investigate the origin of negative longitudinal piezoelectric coefficients of piezoelectric polymers, which is definitely opposite to those of common piezoelectric ceramics. In addition to the mainly discussed issue about MPB behaviors of ferroelectric polymers, we also introduce the consideration about polymer chirality resulting in relaxor ferroelectric properties. When the physics of ferroelectric polymers is unveiled, we can improve the piezoelectric and pyroelectric properties of ferroelectric polymers and contribute to the development of next-generation sensor, energy, transducer and actuator applications.

• 융합정보논문지
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• 제10권11호
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• pp.1-8
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• 2020

전력 소비량이 극대화 되면서 개인 전력 중개사업자 및 전력 생산설비의 증가에 따라 전력 설비를 유지, 보수하기 위한 현장 설비 담당자들을 위한 증강현실 기반 모니터링 시스템들에 대한 연구가 활발하게 진행되고 있다. 그러나 기존 증강현실 기반 모니터링 시스템들의 경우 외부 환경, 설비의 복잡성, 조명환경에 대한 간섭 등의 문제로 인하여 정확한 패턴 검출이 어려우며, 전력 설비에 대한 다양한 센싱 정보 및 서비스 정보를 하나의 패턴에 매칭하지 못하는 문제가 있다. 이로 인하여 전력 설비의 센서별로 단일 이미지의 패턴을 이용하여 센서 정보를 매칭하기 때문에 모든 정보를 증강하여 제공하기 위해 다수의 이미지 패턴이 필요하다. 본 논문에서는 다수의 특징 패턴들로 구성된 단일 이미지에서 특징 패턴들의 배열조합을 통해 다수의 정보를 매칭하여 제공하는 단일 이미지 패턴 배열화 기법을 제안한다.

• Steel and Composite Structures
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• 제19권1호
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• pp.131-152
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• 2015

Easy detection and evaluation of defect in the tube structure is a continuous problem and remains a significant demand in tube inspection technologies. This study is aimed to automate defect detection using the pattern recognition approach based on the classification of high frequency stress wave signals. The stress wave signals from vibrational impact excitation on several tube conditions were captured to identify the defect in ASTM A179 seamless steel tubes. The variation in stress wave propagation was captured by a high frequency sensor. Stress wave signals from four tubes with artificial defects of different depths and one reference tube were classified using the autoregressive (AR) algorithm. The results were demonstrated using a dendrogram. The preliminary research revealed the natural arrangement of stress wave signals were grouped into two clusters. The stress wave signals from the healthy tube were grouped together in one cluster and the signals from the defective tubes were classified in another cluster. This approach was effective in separating different stress wave signals and allowed quicker and easier defect identification and interpretation in steel tubes.

• 로봇학회논문지
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• 제8권3호
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• pp.156-163
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• 2013

This paper describes a flexible visuo-haptic display module. We have developed a flexible electro-active polymer (EAP) actuator and a thin flexible visual display with $3{\times}3$ array configuration via polymer technology. The flexible actuator consists of nine EAP cells vertically moving in response to change in their thickness. The flexible display uses polymer based optical waveguide allowing light to scatter only at specific area. The display film is transparent and identically designed to the array pattern to fit for the arrangement of actuator cells. A pressure sensor is installed under the integrated module. The performance of the actuator is proved to be sufficient for satisfying perceivable range of human touch sense. The integrated system can provide interactive haptic feedback such as key pressing, contact vibration sensations, and etc. in accordance with user input.