• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.2
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• pp.177-183
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• 1999

The major object of this study is to investigate experimentally the experimental equation by the non-destructive testing methods of ultrasonic pulse velocity, rebound number, combined method of ultrasonic pulse velocity and rebound number, maturity which are applicable to the evaluation of compressive strength of concrete at early ages. Also test result of mix are statistically analyzed to infer the correlation coefficient between the maturity and the compressive strength of concrete. The results show good application of Logistic curve for estimating strength development under various curing temperature. The relation between ultrasonic pulse velocity, rebound number, combined method of ultrasonic pulse velocity and rebound number and compressive strength of concrete have low correlation coefficient, but maturity method show good correlation coefficient.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.183-184
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• 2022

In this study, harmonics of 100 kHz ultrasonic pulse transmitted through concrete exposed to high temperature were evaluated. Concrete exposed to high temperatures deteriorates its mechanical properties. In ultrasonic pulse, the fundamental wave was attenuated by the deterioration of the concrete. In addition, it was possible to confirm the occurrence of harmonics. It is thought that the fundamental and harmonics of ultrasonic pulse greatly affected by the internal structure of concrete.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.13 no.2
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• pp.88-116
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• 2009

Background : EBM (the evidence based medicine) is the direction of the development for oriental medicine. The pulse meter-analyzer is the important part to standardize the pulse diagnosis. When we set up the direction of the study on the pulse meter-analyzer, the awereness about the pulse meter and analyzer of the clinical oriental medical doctors as consumers is very important. Objectives : In order to prepare for the mutual study and the export strategy on the pulse meter-analyzer of Korea and China, the attitude of the study and the grasp of the awereness about the pulse meter-analyzer of the Chinese medical doctors are very important. Methods : We developed the several items as the important factor of the development of the pulse meter and analyzer. They were translated by chinese medical doctor. The investigation for demend was conducted during 3 months in Guangzhou City, Guangdong Province, China. The results of the investigation was done the statistical method of frequency analysis, Chi-squared test, correspondence analysis. Results : The most important differentiation of symptom is the symptom of JANG-BU(臟腑). The method of the utility in the pulse diagnosis is Chon-Gu (寸口) pulse diagnosis and the research on Chon-Kwan-Cheok(寸關尺) is the most important measurement factor. And the typical the old pulse is the little-fine weak pulse. The pulse meter-analyzer is most suitable to the diagnosis of the hypertension and the arteriosclerosis. Conclusion : The development of the pulse analyzer including the requests of Korean and Chinese medical doctors is very important. Specially the researches on the influence factors of the traditional diagnosis and the environment of the measurement are important for developing the pulse analyze.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.1023-1026
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• 2013

The electronic equipment which was exposed to high level pulsed radiation is damaged as Upset, Latchup, and Burnout. Those damages has come from the instantaneous photocurrent from electron-hole pairs generated in itself. Such damages appeared as losses of power in military weapon system or of blackout in aerospace equipment and eventually caused in gross loss of national. In this paper, we have implemented a RDC(Radiation detection and control module) as part of the radiation protection technology of the electronic equipment or devices from the pulsed gamma radiation. The RDC which is composed of pulsed gamma-ray detection sensor, signal processors, and pulse generator is designed to protect the important electronic circuits from the pulse radiation. To verify the functionality of the RDC, LM118s which had damaged by the pulse radiation were tested. The test results showed that the test sample applied with a RDC was worked well in spite of the irradiation of the same pulse radiation. Through the experiments we could confirm that the radiation protection technology implemented with RDC had the functionality of radiation protection to the electronic devices.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.90-95
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• 2014

The system design and the system performance analysis of 3D imaging laser radar system for the mapping purpose is addressed in this article. For the mapping, a push-bloom scanning method is utilized. The pulsed fiber laser with high pulse energy and high pulse repetition rate is used for the light source of laser radar system. The high sensitive linear mode InGaAs avalanche photo-diode is used for the laser receiver module. The time-of-flight of laser pulse from the laser to the receiver is calculated by using high speed FPGA based signal processing board. To reduce the walk error of laser pulse regardless of the intensity differences between pulses, the time of flight is measured from peak to peak of laser pulses. To get 3D image with a single pixel detector, Risley scanner which stirs the laser beam in an ellipsoidal pattern is used. The system laser energy budget characteristics is modeled using LADAR equation, from which the system performances such as the pulse detection probability, false alarm and etc. are analyzed and predicted. The test results of the system performances are acquired and compared with the predicted system performance. According to test results, all the system requirements are satisfied. The 3D image which was acquired by using the laser radar system is also presented in this article.

• Journal of Naturopathy
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• v.10 no.1
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• pp.33-41
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• 2021

Purposes: We studied whether forest bathing is effective in improving the stress of the human body. Therefore, we investigated changes in pulse rate, stress index, and autonomic nervous system after 2 hours of forest bathing on Jeju Samdasu Forest Methods : The study was conducted before and after forest bathing through heart rate variability and questionnaire. Results: After forest bathing, the average pulse rate of the experimental group was significantly increased. The stress index significantly decreased in the post-test in the experimental group. The cumulative stress, sympathetic activity (LF), parasympathetic activity (HF) change, and LF/HF ratio were slightly different from those of post-test in the experimental group, but were not statistically significant. In the survey of job stress average index and state characteristic anxiety index through questionnaire, it decreased significantly after forest bathing (p<.001). Conclusions: The Samdasu forest bathing has been proven effective in enhancing pulse and reducing stress, so it is evaluated that forest bathing is effective in promoting health.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.100-105
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• 2002

In order to investigate how the chassis frame stiffness including body structure affects vehicle handling characteristics, in this paper, objective test evaluations such as steady state circle maneuvering test and pulse input transient test are performed. The basic steer characteristics can be obtained from stability factor and 4 parameter method is used to evaluate vehicle handling characteristics between original vehicle and the other with reinforced chassis. The result shows that vehicle with reinforced chassis has advantages in handling characteristics.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.2
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• pp.137-146
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• 2001

The non-destructive tests are widely used to predict the strength of existing structures. The purpose of the present study is to propose the prediction equations for strength evaluation of concrete structures. The present study focuses on the rebound method and ultrasonic pulse velocity method for quartzite aggregate concrete. The major test variables include the water-cement ratio and curing methods. The water-cement ratio are 0.4, 0.5, 0.6, 0.7, respectively and the curing method covers ail-dry condition and standard curing condition. The prediction equations for strength of concrete are proposed from the present test data.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.78-79
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• 2015

For estimating compressive strength of concrete, non-destructive test has conducted generally. It used experimental equation to calculate compressive strength from construction. This study investigated experiment to apply non-destructive test, based on fresh property, compressive strength and ultrasonic pulse velocity of high performance concrete. And it conducted to compare various proposed equation.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.81-82
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• 2006

This paper presents the influence of the compositions of sintered Ti-Ni alloys on their thermo-mechanical properties. The Ti-Ni alloys having various compositions from 50at%Ni to 51at%Ni were sintered using elemental Ti and Ni powders by a pulse-current pressure sintering equipment. The deformation resistance in stress-strain curves increased with an increase in Ni content. In the case of Ti-50at%Ni, tensile strength and elongation were more than 500 MPa and 7%, respectively. The increase in Ni content also makes the transformation temperatures lower. The deformation resistance at a test temperature change from 293K and 353K in isothermal tensile test increased with elevating test temperature.