• Journal of Advanced Marine Engineering and Technology
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• 제25권2호
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• pp.338-344
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• 2001

According to the MARPOL 73/78 of Convention, all ships should have oil filtering equipment and 15 ppm bilge which satisfy Requirements of MARPOL 73/78. This study is concerned with designing and manufacturing a prototype Oil content Meter(OCM) used in machinery area of ship. The prototype OCM is composed of two parts which are oil content sensing module and data processing unit. The oil content sensing module consists of infra-red light source, photo-diode light receivers, and a glass tube for bilge water sample. The data processing unit has a micro-processor as hard core and peripheral devices. The experimental results of prototype OCM and analysis of collected data reveal linear property between transmitted light and scattered light as long as the bilge water has low level content of oil. And this linear property leads to a oil content detecting method which is programmed and loaded into the data processing unit. The performance of the prototype OCM is compared with that of the commercial OCM in the market.

• 동력기계공학회지
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• 제14권6호
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• pp.47-53
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• 2010

A stabilizer link connects the stabilizer bar to the lower arm of the suspension. When a vehicle is turning, lateral forces from the tire are transmitted through the stabilizer link into the stabilizer bar. The stabilizer bar will twist, thus adding rigidity to the vehicle body. In this study, the stabilizer link body was manufactured by using composite material with POM-GF25%. Therefore, the strength evaluation of stability link body with composite material carried out from tensile, wear and fatigue test. The tensile strength between the stability link body with composite material and the rod with knurling was the largest of four types of rod. In Analyzing materials property using optical sensing technique of stabilizer link for automobile parts, its has been identified the safety.

• 대한원격탐사학회지
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• 제21권5호
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• pp.433-443
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• 2005

This paper show that, without installation of expensive VR (Virtual Reality) program, the sharing information is possible through posting three-dimensional road structures on the web, and avoiding the conventional top-down decision making method, fast bottom-up communication is possible base on the Virtual GIS (Geographic Information System). In this paper, using Viewpoint Scene Builder, internet-based software, the transformation was conducted to give pertinent type for web posting. In order to use the completed route at the scene builder, the output with ASCII Export is required, and ASE (ASCII Scene Export) contains the property information including the coordinate and frame of mesh vertex. Through in advance recognition of the problems regarding route design and petition due to environmental rights infringement, the time and cost due to design alteration can be reduced. It's difficult to provide VR based on the internet because file that embodied with internet GIS was complicated and its capacity comes to scores of mega-bites. But, this study provides VR with internet according to a basis by simplification of files.

• 방송공학회논문지
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• 제17권6호
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• pp.954-963
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• 2012

Orthogonal matching pursuit (OMP) 알고리듬은 underdetermined 시스템에서 희소 신호를 복구하는 대표적인 greedy 알고리듬으로 많은 관심을 받고 있다. 본 논문에서는 OMP 알고리듬의 반복과정에서 후보 support 집합들을 구성하여 마지막 반복과정에서 최소 잔차를 이용하는 multiple candidate matching pursuit (MuCaMP) 기법을 제안한다. MuCaMP 가 완벽한 신호 복원을 보장하기 위한 restricted isometry property (RIP)를 이용한 충분조건, ${\delta}_{N+K}<\frac{\sqrt{N}}{\sqrt{K}+3\sqrt{N}}$을 제시한다. 실험을 통해 후보 support 집합들의 크기에 따른 성능과 MuCaMP의 복원 성능이 기존의 기법들에 비해 우수함을 확인하였다.

• 전기학회논문지
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• 제66권5호
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• pp.765-771
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• 2017

This paper presents concurrent design methods of surface permanent magnet synchronous machines for saliency-tracking self-sensing position estimation. Magnetic saliency for the self-sensing is created by stator pole saturation due to the rotor zigzag leakage flux. The power conversion properties such as saliency ratio, torque ripple, and efficiency vary according to motor design. The property change due to design modification is analysed by using finite element analysis, and with the appropriate design modification, proper saliency is created while preserving their power conversion capabilities.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 추계학술대회
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• pp.461-470
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• 2009

A railroad has a benefit of the mass transportation of a passenger and cargo, but just a time of accident could cause a huge loss of a human life and property. Especially, a typhoon and a localized torrential downpour usually happened in summer season have caused average 38.29 times of the missing roadbed which support the railroad in recent 7 years. If a train would pass on this railroad which the roadbed was missed, there could be a huge accident and many people will die. But, the security issue is not satisfied because the method of sensing the missing roadbed is depending solely on the naked eye inspection by a person in charge. So, in this study, I would like to suggest the missing roadbed real-time sensing and train operation system to reduce the possibility of the railroad accident by controlling the operation of train when the missing roadbed condition would be sensed in the real-time system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4645-4664
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• 2019

It is significant to construct deterministic measurement matrices with easy hardware implementation, good sensing performance and good cryptographic property for practical compressed sensing (CS) applications. In this paper, a deterministic construction method of bipolar chaotic measurement matrices is presented based on binary sequence family (BSF) and Chebyshev chaotic sequence. The column vectors of these matrices are the sequences of BSF, where 1 is substituted with -1 and 0 is with 1. The proposed matrices, which exploit the pseudo-randomness of Chebyshev sequence, are sensitive to the initial state. The performance of proposed matrices is analyzed from the perspective of coherence. Theoretical analysis and simulation experiments show that the proposed matrices have limited influence on the recovery accuracy in different initial states and they outperform their Gaussian and Bernoulli counterparts in recovery accuracy. The proposed matrices can make the hardware implement easy by means of linear feedback shift register (LFSR) structures and numeric converter, which is conducive to practical CS.

• Advances in nano research
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• 제14권3호
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• pp.285-294
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• 2023

The dynamic and sensing performances of nanomechanical resonators with their different boundary conditions are studied based on surface elasticity-based modeling and simulation. Specifically, the effect of surface stress is included in Euler-Bernoulli beam model for different boundary conditions. It is shown that the surface effect on the intrinsic elastic property of nanowire is independent of boundary conditions, while these boundary conditions affect the frequency behavior of nanowire resonator. The detection sensitivity of nanowire resonator is remarkably found to depend on the boundary conditions such that double-clamping boundary condition results in the higher mass sensitivity of the resonator in comparison with simple-support or cantilever boundary condition. Furthermore, we show that the frequency shift of nanowire resonator due to mass adsorption is determined by its length, whereas the frequency shift is almost independent of its thickness. This study enables a design principle providing an insight into how the dynamic and sensing performances of nanomechanical resonator is determined and tuned.

• 센서학회지
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• 제33권3호
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• pp.119-124
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• 2024

Effective fire sensing is important to protect lives and property from the disaster. In this paper, we present an intelligent visual sensing method for detecting fires based on machine learning techniques. The proposed method involves a two-step process. In the first step, fire and non-fire images are used to train a convolutional neural network (CNN), and in the next step, feature vectors consisting of 256 values obtained from the CNN are used for the learning of a support vector machine (SVM). Linear and nonlinear SVMs with different parameters are intensively tested. We found that the proposed hybrid method using an SVM with a linear kernel effectively increased the recall rate of fire image detection without compromising detection accuracy when an imbalanced dataset was used for learning. This is a major contribution of this study because recall is important, particularly in the sensing of disaster situations such as fires. In our experiments, the proposed system exhibited an accuracy of 96.9% and a recall rate of 92.9% for test image data.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1314-1317
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• 1997

For realizing artificial skin sensing as a final goal, a mono-material pressure-conductive rubber sensor which is also sensitive for temperature is described. Firstly, discimination of the hardness and the thermal property of material using a proposed sensor is presented. Furthermore, a tactile sensor constints of four pressure-conductive rubber sensor to discriminate surface model which imitaties the surface roughness of material is proposed.