• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.168-171
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• 2003

As vehicles are more intelligent for convenience and safety of drivers, the in-vehicle networking systems and smart modules are essential components for intelligent vehicles. However, for the smart module to widely apply to the IVN systems, two problems are considered as follows. Firstly, because it is very difficult that transducer manufacturers developed the smart module that supports the existing all IVN protocols, the smart module must be independent to the type of networking protocols. Secondly, when the smart module is exchanged due to its failure, it is necessary how the transducer is only exchanged without exchange of the microprocessor and network transceiver. This paper deals with the IEEE 1451 based smart module that describes the digital interface between a network transceiver and sensor module. Finally. efficiency of the IEEE 1451 based smart module was evaluated on the experimental model.

• 비파괴검사학회지
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• 제25권6호
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• pp.467-474
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• 2005

The expanded multi-Gaussian beam model has recently been developed that can calculate the radiation beam field from a single, rectangular transducer with great computational efficiency. In this study, this model is adopted to calculate the radiation beam field for a phased array transducer with various time delays to achieve steering and/or focusing. The calculation beam fields are compared to those obtained by well known Rayleigh-Sommerfeld integral that provides the exact solution in order to explore the validity of the expanded multi-Gaussian beam model And then, this study proposes a complete ultrasonic measurement model including the expanded beam model, far-field scattering model and system efficiency, Using the proposed model, phased array ultrasonic testing signals for a flat-bottomed hole with/without focusing were performed.

• 대한한방내과학회지
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• 제34권2호
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• pp.147-154
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• 2013

Objectives : The aims of this study was to find out whether Jichul-hwan (JCH) extract has an effect on gastric contractility in conscious rats by using a force transducer implanted in the body of the stomach. Methods : The force transducer (model: F-081S, Starmedical, JAPAN) was implanted to the exterior wall of the stomach body in rats. The gastric contractility was measured 30 minutes before and after administration of JCH (110.1 mg/kg). The control group was administrated with normal saline instead of JCH to compare the effect of JCH. The gastric contractility of the control group (normal saline: NS) was also measured 30 minutes before and after administration of NS. Results : The ratio of gastric contractility between before and after medication by JCH was $1.707{\pm}0.731$, and with NS was $0.701{\pm}0.541$. The gastric motility increased by JCH was significantly higher than NS. Conclusions : JCH extract increases gastric contractility in conscious rats. We could expect that this drug would be effective in the treatment of functional dyspepsia or post-surgical gastroparesis.

• 한국정밀공학회지
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• 제19권3호
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• pp.39-45
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• 2002

A simple and low cost stylus profiler made of ferrite cores is developed. The devised profiler consists of a contact probe, a measuring transducer, a signal processing unit, and a motorized stage. The contact probe attached to 4-bar spring maintains sufficient stiffness to protect disturbances. An overlap-area type inductive position sensing system is selected as a measuring transducer, which has high sensitivity, repeatability and linearity. The transducer is composed of coil bundles and ferrite cores which have good electromagnetic characteristics in spite of low cost. The repeatability of the profiler with the proposed inductive sensing system is better than 50nm. Experimental results are shown that the proposed profiler can measure the line or 3D profile of an object with sub-micron features.

• 한국결정성장학회지
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• 제26권4호
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• pp.139-144
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• 2016

Tonpilz 트랜스듀서의 거동에 미치는 압전 소재의 형상과 크기의 효과에 대하여 유한요소법을 통한 컴퓨터 모사를 통하여 연구하였다. 도넛 형태의 압전체의 직경과 높이 그리고 쌓아올린 stack의 수를 변수로 고려하였고 최종적으로 소재 자체를 특성이 뛰어난 단결정 소재로 변환하였을 때 그 특성인 출력과 TVR 대역폭이 어떻게 변하는지를 모사하였다. 그 결과, 리랙서 단결정을 활용함으로써 같은 구조에서 출력을 10배 정도 향상시킬 수 있음을 확인하였다.

• Transactions on Electrical and Electronic Materials
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• 제18권6호
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• pp.334-337
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• 2017

In this paper, to develop the ceramics with high $d_{33}$ and high $Q_m$ for ultrasonic transducer applications, $0.10Pb(Ni_{1/3}Nb_{2/3})O_3-0.07Pb(Mn_{1/3}Nb_{2/3})O_3-0.83Pb(Zr_{0.5}Ti_{0.5})_{0.83}O_3$ (PNN-PMN-PZT) ceramics were sintered at $940^{\circ}C$ using $CuO-Li_2CO_3-Bi_2O_3$ (CLBO) as a sintering aid by a traditional solid-state technique. The influence of zinc oxide additive on the physical properties of the prepared ceramics were systematically investigated. The R-T (rhombohedral-tetragonal) phase coexistence was found in the ceramics without zinc oxide additive and with increasing amounts of ZnO additive, the specimens showed a tetragonal phase. The formation of a liquid phase between ZnO and $Bi_2O_3$ contributed significantly to the grain growth of specimens. For the 0.1 wt% ZnO ceramics, the optimal physical properties of $d_{33}=370pC/N$, ${\varepsilon}_r=1,344$, $k_p=0.621$, and $Q_m=1,523$ were obtained.

• 한국음향학회지
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• 제11권3호
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• pp.67-73
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• 1992

電磁誘導形 音源裝置는 짧은 펄스의 음파를 수중에 放射시킬 수 있어, 높은 距離分解能이 요구되는 해저 탐사용 음원 또는 수중 음파전달 특성시험용 음원등으로 널리 이용될 수 있다. 본 연구에서는 Eisenmenger가 제안한 형태의 電磁誘導形 音源裝置를 설계 제작하여, 放射되는 음파의 파형을 관찰하고, 그 주파수 특성을 분석하였다. 제작된 음원으로부터는 약 한 주기의 짧은 충격 펄스의 초음파가 얻어졌으며, 그 음압은 진동판의 두께가 얇은 경우에 크며, 콘덴서의 용량에 비례하여 증가하였다. 발생된 초음파의 중심 주파수는 振動板의 두께가 두꺼운 경우에 높으며, 콘덴서 용량이 증가할수록 낮아지고, 대역폭도 좁아졌다.

• 한국음향학회지
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• 제32권6호
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• pp.502-508
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• 2013

본 논문에서는 1-3 복합체 형태의 전도성 후면층을 이용한 2D 배열 초음파 트랜스듀서를 설계 및 제작하고 그 특성을 평가하였다. 1-3 복합체 형태의 전도성 후면층은 일반적인 재료를 사용해 널리 쓰이는 1-3 복합체 공정을 통하여 제작되었다. 본 연구의 대상이 되는 2D 배열 트랜스듀서는 4,096개의 구동 소자로 이루어져 있고, 각 소자의 중심주파수 및 비대역폭은 각각 3.5 MHz 및 60 % 이상을 목표로 설계하였다. 제작된 트랜스듀서는 중심주파수 및 비대역폭 목표치를 만족하였으며, 전체 구동 소자간의 특성도 0.81 dB 이내로 균일하였다. 따라서 본 연구에서 제시한 전도성 후면층의 2D 배열 초음파 트랜스듀서에 대한 적용 가능성이 검증되었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.395-398
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• 1997

Human pulse represents the physical characteristics of heart and cardiovascular system. Therefore, malfunctions and errors of heart and cardiovascular system can be determined by using an automatic diagnosis system that can detect the pulse signal. Not only will the computerised system preclude the possibilities of observational errors by giving an accurate measurement with great stability, but minimize the possibilities of misinterpretation by using an automated diagnostic logic. A new combinational fiber-optic sensor, which has a detecting part and a transmitting part was used to acquire radial pulse signal noninvasively. The development of P-5 transducer makes it possible to obtain more effective detection and obvious display of pulse signals in the aspect of reliability. Using P-5 transducer in the field of plethysomography and MAC- JIN, one of our diagnoses in Korean traditional medicine, it is expected that we can ontain quantitative and valuable information or the diagnosis of human pulses.

• Journal of Biosystems Engineering
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• 제18권4호
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• pp.371-381
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• 1993

Threshing operation is performed by impact, compression and friction forces inside the thresher. These values should be appropriate to the crop condition to enhance the threshing and separating efficiency and to decrease the grain damage. To analyze the threshing process inside the rasp-bar type thresher, impact, friction and compression forces were measured using transducers with strain gage circuits. To measure the impact forces and friction forces between the rasp-bar and crop, full bridge strain gage circuit was built on the rasp-bar holder. To measure the compression forces and circumferential friction forces between the concave and crop, two sets of full bridge strain gage circuits were built on the T-type concave transducer. Threshing work of wheat crop with 12% of moisture content was performed at 3 levels of compression ratio and with 3 replications. Each transducer could not measure the exact forces continuously because the transducer oscillates with the forces. However they could measure maximum forces and force distribution according to the time. Average friction coefficients between crop and concave was 0.61 not showing any significant difference according to the compression ratio. Average acceleration of the crop in the cylinder appeared from $70.6m/s^2$ to $140.8m/s^2$ according to the compression ratio. The velocity of the crop at the exit of the cylinder appeared from 10.7m/s to 15.0m/s according to the compression ratio.