• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.313-318
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• 2001

In this paper, the well-conditioned observer is designed to be insensitive to the ill-conditioning factors in transient and steady-state observer performance. A condition number based on $L_2-norm$ of the eigenvector matrix of the observer matrix has been proposed on a principal index in the observer performance. For the well-conditioned observer design, the non-normality measure and the observability condition of the observer matrix are utilized. The two constraints are specified into observer gain boundary region that guarantees a small condition number and a stable observer. The observer gain selected in this region guarantees a well-conditioned and observable property. In this study, this method is applied to the Luenberger observer and Kalman filters. In designing Kalman filters for small order systems, the ratio of the process noise covariance to the measurement noise covariance is a design parameter and its effect on the condition number is investigated.

• Toxicological Research
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• v.17
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• pp.197-199
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• 2001

Enhancement of antigen-specific IgE is a hallmark of allergic hyperresponsiveness, therefore it is necessary to adopt or develop a highly sensitive and specific assay for determination of allergen-specific IgE levels in vivo. In this presentation, we introduce an ELISA (enzyme linked immunosorbent assay) system developed to measure the levels of chicken egg ovalbumin (OVA)-specific IgE in serum. The ELISA method uses a commercially available purified rat anti-mouse IgE as a capture Ab and biotinylated OVA as a detection reagent. Avidin-peroxidase with its substrate is used for color development resulting in optical density measurement at 405 nm. The ELISA system produces a highly sensitive dose-response relation-ship between optical density levels and the dilution titer of the OVA-IgE standard serum but no cross-reaction with unrelated IgE or IgG. It is believed that the system is an Efficient tool to delineate an adjuvant effect of environmental pollutants on development of asthmatic and atopic responses.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.429-434
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• 2001

This paper has been presented the dynamic effect by the journal speed, eccentricity and source positions in order to overcome the defects of air bearing such as low stiffness and damping coefficient. Choosing two row sources position of air bearing is different from previous investigations in the side of pressure distribution of air film by the wedge effects. An experimental study was performed to compare theoretical analysis. The dynamic stiffness was measured in actual cutting. It helps predicting of air spindle s characteristic in machining of die more precisely. The results of investigated characteristics was applied to air spindle for high speed milling.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.143-147
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• 1998

As the accuracy of manufactured goods needed high-accuracy processing has made the efficiency of NC and measurment technology develop, the innovation of machine tools has influence the development of the semi-conductor and optical technology. We can mention that a traction role of the acceleration for the development like that depends on the development of the measurement technics - Stylus instrument method, STM, SEM, Laser interferometer method - which are used for measuring the movement accuracy of machine tools. The movement error factors in movement accuracy are expressed as yaw, roll, and pitch etc. Machining center has 21 movement error factors including of 3 axies joint errors because that has 3 axies and has been measured as the standard of the unloaded condition until now inspite of getting static, dynamic, and servo-gain errors in the case of expending the error range. Therefore, this study tries to measure position accuracy according to loading on the X-Y table of the machining center.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1173-1177
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• 1990

Cerebellar Model Linear Associator Net(CMLAN), a kind of neuro-net based adaptive control function generator, was applied to the problem of direct inverse calibration of three and six d.o.f. POMA 560 robot. Since CMLAN autonomously maps and generalizes a desired system function via learning on the sampled input/output pair nodes, CMLAN allows no knowledge in system modeling and other error sources. The CMLAN based direct inverse calibration avoids the complex procedure of identifying various system parameters such as geometric(kinematic) or nongeometric(dynamic) ones and generates the corresponding desired compensated joint commands directly to each joint for given target commands in the world coordinate. The generated net outputs automatically handles the effect of unknown system parameters and dynamic error sources. On-line sequential learning on the prespecified sampled nodes requires only the measurement of the corresponding tool tip locations for three d.o.f. manipulator but location and orientation for six d.o.f. manipulator. The proposed calibration procedure can be applied to any robot.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.95-101
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• 2000

To measure springback ratio of thin sheet or plate, winding bend rig is made. It bends a specimen with keeping its curvature constant and measures the bending angles before and after release of bending load. To check the performance of the bend rig, we calculated the bending moment by two ways which are based on simple beam theory. One is that the bending moment is calculated by using the results of bending test, and the other is that the moment is calculated by using the results of tensile tests. The former may entails the effect of the friction between bending pin of the rig and the surface of specimen, but the latter does not contain any effects of the friction since the bending moment is obtained by using tensile tests. Nevertheless, the values of the two bending moment shows the same level of bending moment, which implies that the friction does not influence on the value of springback ratio in spite of the presence of friction within the cope of the test performed in this experiment.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.294-296
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• 1988

The tomographic imaging that employs ultrasonic echos has achieved outstanding advances in recent years, and today, ultrasonic diagnostic equipment has become the tool that is absolutely indispensible for clinical operations. Meanwhile, the feasility of measuring blood flow in the heart and vessels by the use of Doppler effect in ultrasonic waves is a well known fact. With respect to the method of blood flow measurment, there are two kinds which employ continous wave and pulse wave doppler system. In this paper, we describe the measurment of Blood flow-turbulence using general purpose Digital Signal Processing Board which had been implemented for the purpose of real-time spectrum analyser. Blood flow-turbulence means the blood-flow behavior. And it's value proportional to the spectrum variance. Therefore mean frequency of blood signal and variance provide useful diagnostic information. We have applied to the major arteries and vein, obtained the information about the time dependent blood-flow behavior.

• KSBB Journal
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• v.16 no.2
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• pp.183-187
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• 2001

The biological activities of wastewater and sludge taken from the wastewater treatment process of Hyangnam pharmaceutic factories in Hwaseong, Kyeonggi-Do was measured using a respirometer. Oxygen uptake rate (OUR) was used as a tool for measuring biological activity. OUR was measured for varying amounts of sludge and organic chemicals in wastewater, and its toxicity was evaluated. Maximum OUR was observed as 61, 75, and 89 mg O$_2$/L/hr when sludge was added as 3, 5, and 10% of total volume, respectively. When the concentration of organic chemicals was changed to 1,486, 337, and 164 mg COD/L, maximum OUR was 53, 13, 8 mg O$_2$/L/hr, respectively. The toxicity test results showed that there seemed that there seemed to be no observable toxic effect on microbes in pharmaceutic wastewater.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.518-522
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• 2015

Green Construction is the construction activities that conserved energy, land, water and material to reduce the negative effect to the environment while assuring essential demand on quality and safety during project construction. This paper critically examine the contribution of awareness and understanding, green construction practices and green construction innovation with the green construction benefits. A measurement model based on the theoretical framework and exploratory factor analysis was developed and tested using structural equation modelling technique. This study employs a survey research methodology involving a total of 346 respondents among construction contractors, developers, clients and consultants in the construction industry. The findings indicate that the awareness and understanding, green construction practices and green construction innovation are significant predictors of the green construction benefits. From the practical perspective, the findings should alert the construction participants on the need of awareness and understanding, green construction practices and green construction innovation towards the green construction benefits. In addition, the findings can be used as diagnostic tool for continuous improvements in the Malaysian construction industry.

• Journal of radiological science and technology
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• v.43 no.5
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• pp.375-382
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• 2020

PET/CT is a medical equipment that detects 0.511 MeV of gamma rays. The radiation workers are inevitably exposed to ionizing radiation in the process of handling the isotope. Accordingly, PET/CT workers use syringe shields made of lead and tungsten to protect their hands. However, lead and tungsten are known to generate very high scattering particles by interacting with gamma rays. Therefore, in this study, we tried to find out the effect on the scattering particles emitted from the syringe shield. In the experiment, first, the exposure dose to the hand (Rod phantom) was evaluated according to the metal material (lead, tungsten, iron, stainless steel) using Monte Carlo simulation. The exposure dose was compared according to whether or not plastic is attached. Second, the exposure dose of scattering particles was measured using a dosimeter and lead. As a result of the experiment, the shielding rate of plastics using the Monte Carlo simulation showed the largest difference in dose of about 40 % in lead, and the lowest in iron, about 15 %. As a result of the dosimeter test, when the plastic tape was wound on lead, it was found that the reduction rate was about 15 %, 28 %, and 39 % depending on the thickness. Based on the above results, it was found that 0.511 MeV of gamma ray interacts with the shielding tool to emit scattered rays and has a very large effect on radiation exposure. However, it was considered that the scattering particles could be sufficiently removed with plastics with a low atomic number. From now on, when using high-energy radiation, the shielding tool and the skin should not be in direct contact, and should be covered with a material with a low atomic number.