• Korean Journal of Optics and Photonics
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• v.21 no.5
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• pp.206-213
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• 2010

We fabricated and characterized a compact endoscopic catheter for optical coherence tomography. The optical delay line (ODL), composed of a cylindrical piezoelectric transducer (PZT) and an optical fiber, was operated with a 1 kHz sinusoidal driving wave in the time-domain. When the ODL was driven with a sinusoidal wave function, the axial scanning speed was 6 m/s and the axial acquisition rate was 2000 line/s at a depth of about 3 mm. Endoscopic OCT images of a human finger and earhole were successfully obtained with an image rate of ten frames per second.

• Journal of Power System Engineering
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• v.10 no.3
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• pp.45-50
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• 2006

In this paper, creep tests of Mg-Zn-Mn and Mg-Zn-Mn-Ca alloy casted by mold under the temperature range of 473.00-573.00K, and the stress range of 23.42-87.00Mpa were done with the equipment of automatic controlled temperature and computer for data acquisition. The activation energies were obtained by relationship between creep rate and temperature, and the stress exponents were obtained by relationship between creep rate and stress. From the experiment results, the activation energies of Mg-Zn-Mn and Mg-Zn-Mn-Ca alloy were 149.87kJ/mol, 147.97kJ/mol, respectively, and the stress exponents of those alloy were 5.13, 5.59, respectively, under the temperature of 473.00-493.00K and the stress range of 62.43-78.00Mpa. And the activation energies of those alloy were 134.41kJ/mol, 129.22kJ/mol, respectively, and the stress exponent of those alloy were 3.48, 3.77, respectively, under the temperature of 553-573Mpa and the stress range of 23.42-39.00Mpa. Also the lifes of Mg-Zn-Mn-Ca alloy were higher than those of Mg-Zn-Mn alloy, and the results of SEM showed fracture surfaces under low temperature had smaller dimples than those under high temperature.

• Journal of Biomedical Engineering Research
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• v.12 no.4
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• pp.235-242
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• 1991

This research has reported that the selection and assessment of treatment in anxiety disorders depend to a large extend on patient reports of somatic symptomatology. However, the correspondence between such reports and actual physiological data Is unknown as the physiological measures used were taken in laboratory. The purpose of the ambulatory momboring device is, therefore, to present for analysis physiological data derived from the sub jects during their daily activities. The physiological parameters of interest are heart rate, respiratory rate, skin conductance level/response, skin temperature, and activity level. This device had an microcomputer based data acquisition unit, Interfaced to it for the purpose of data collection. The data is collected usually over a period of 12 hours. The data from the ambulatory monitoring device can be used to assess the psychophysiology of anxiety in the field. The data from the device will also reveal if patients who report different sets of symptoms differ physiologically too. Thls will help physicians for the right kind of treatment and also solve the many uncertainties that have existed thus far in quantizing anxiety.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.381-385
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• 2006

2008년 발사를 목표로 개발되고 있는 통신해양기상위성(COMS: Communication, Ocean and Meteorological Satellite)는 기상 관측과 해양 관측 임무 및 통신 임무까지 수행하는 정지궤도 위성이다. 통신해양기상위성은 크게 탑재체와 지상국으로 나눌 수 있고 지상국은 다시 통신 임무를 위한 CTES(Communication Test Earth Station), 해양/기상 임무를 위한 IDACS(Image Acquisition and Control System), 그리고 위성 관제와 운영을 위한 SGCS(Satellite Ground Control System)로 구분된다. 이 중 IDACS의 서브시스템 중 하나인 LHGS(LRIT/HRIT Generation Subsystem)는 LRIT/HRIT(Low Rate Information Transmission/High Rate Information Transmission)를 생성하고 배포하는 기능을 가지고 있다. 관측 종료 후 LRIT/HRIT 전송 완료까지 15분 이내로 이루어져야 한다는 기상청의 요구사항을 만족하기 위해서 JPEG 압축 시간도 중요한 요소로 고려되어야 한다. 그래서 본 논문에서는 MTSAT에서 받은 LRIT/HRIT의 자료 처리를 바탕으로 lossless JPEG와 lossy JPEG의 압축 시간을 측정하여 압축률을 비교하여 성능 분석을 해보기로 한다. 이렇게 도출해낸 수치자료는 COMS LHGS 설계에 활용할 수 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.1
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• pp.40-47
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• 2010

In this study, basic research on the thrust control by controling oxidizer mass flow rate of a $GO_2$/PE hybrid rocket is presented. For this purpose, hybrid rocket system including oxidizer flow control system and data acquisition system was developed. To control oxidizer mass flow rate, we used needle valve with stepping motor which was controled by LabVIEW program. During the fundamental experiments, this system managed to follow the pre-programmed (20 N - 10 N - 20 N - 0 N) thrust level.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.9
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• pp.1342-1353
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• 2002

The purpose of this study was to provide the basic information to be helpful in establishing more rational prices discount strategy in prices discount advertising. The experiment design for study was a $3{\times}2{\times}3$ between subject factorial design in which the factors were discount presentation types(discount price presentation/discount rate presentation/discount price and discount rate presentation), existence of normal price presentation(presentation/ non-presentation) and semantic cues(regular sales/markdown on the previous season's product/storehouse opening sales). Thirty subjects were randomized in one of 18 experimental conditions. The subjects of this study were 540 female university students in Kwangju, Korea. The results were as follows; 1. Significant interaction effects between discount presentation types and the semantic cues were found in perceived transaction value(p<.01), perceived acquisition value(p<.05), and purchase intention(p<.05)- It means that discount presentation types in prices discount advertising need to present differently according to price discount types. 2. Significant interaction effects between existence of normal price and the semantic cues were not found. It means that normal price need to present in prices discount advertising regardless of price discount types.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.38-44
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• 2013

In this paper, we designed and implemented a mobile video transmission device with 1080i resolution and 30fps frame rate using wireless multi-access technologies. The video acquisition delay time of 16us and jitter of 21ms for this equipment were obtained, respectively. The device is designed to access various communication networks. In order to evaluate the performance of its video transmission capability, a server and monitoring viewer are implemented. In the performance test using LTE network, 211ms delay time was obtained at 3Mbps transmission. Rendering of 1fps frame rate at the 265kbps transmission was confirmed for the transmission test using Inmarsat network.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.45-45
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• 2003

To evaluate remodeling of infarcted myocardium with contrast-enhanced MRI (co-MRI) at true end-diastole (ED) MRI was performed with a Gyroscan Intera (1.5 Tesla, Philips, Netherlands) in 13 patients with acute subendocardial myocardial infarction. The First exam was done 0-15 days (mean 5.2days) after symptom onset and the second exam 28-88days (mean 49 days) after the first exam. Ce-MRI encompassing the entire left ventricle was performed with a multi-shot, turbo-field-echo, breath-hold sequence and a non-selective, inversion prepulse 10 minutes after the intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg body weight. To allow the long TD, ECG synchronization should use two RR-intervals for one acquisition of a segment of k-space by setting the heart rate to half that of the true heart rate. Trigger delay time (TD) was adjusted to the RR-interval for true end-diastolic imaging. The other typical parameters were TR=5.4ms, TE=1.6ms, voxel size=1.37${\times}$1.37${\times}$10mm, k-space data segmented into 8 segments with 32 lines of segment per two cycles over 16 cardiac circles. The thickness of hyperenhanced myocardium and epicardially nonenhanced myocardium were followed.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.92-92
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• 2003

To evaluate remodeling of infarcted myocardium with contrast-enhanced MRI (co-MRI) at true end-diastole (ED) MRI was performed with a Gyroscan Intera (1.5 Tesla, Philips, Netherlands) in 13 patients with acute subendocardial myocardial infarction. The First exam was done 0-15 days (mean 5.2days) after symptom onset and the second exam 28-88days (mean 49 days) after the first exam. Ce-MRI encompassing the entire left ventricle was peformed with a multi-shot, turbo-field-echo, breath-hold sequence and a non-selective, inversion prepulse 10 minutes after the intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg body weight. To allow the long TD, ECG synchronization should use two RR-intervals for one acquisition of a segment of k-space by setting the heart rate to half that of the true heart rate. Trigger delay time (TD) was adjusted to the RR-interval for true end-diastolic imaging. The other typical parameters were TR=5.4ms, TE=1.6ms, voxel size=1.37$\times$1.37$\times$10mm, k-space data segmented into 8 segments with 32 lines of segment per two cycles over 16 cardiac cycles. The thickness of hyperenhanced myocardium and epicardially nonenhanced myocardium were followed.

• Applied Microscopy
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• v.46 no.1
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• pp.6-13
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• 2016

Fluorescence lifetime imaging microscopy (FLIM) has been considered an effective technique to investigate chemical properties of the specimens, especially of biological samples. Despite of this advantageous trait, researchers in this field have had difficulties applying FLIM to their systems because acquiring an image using FLIM consumes too much time. Although analog mean-delay (AMD) method was introduced to enhance the imaging speed of commonly used FLIM based on time-correlated single photon counting (TCSPC), a real-time image reconstruction using AMD method has not been implemented due to its data processing obstacles. In this paper, we introduce a real-time image restoration of AMD-FLIM through fast parallel data processing by using Threading Building Blocks (TBB; Intel) and octa-core processor (i7-5960x; Intel). Frame rate of 3.8 frames per second was achieved in $1,024{\times}1,024$ resolution with over 4 million lifetime determinations per second and measurement error within 10%. This image acquisition speed is 184 times faster than that of single-channel TCSPC and 9.2 times faster than that of 8-channel TCSPC (state-of-art photon counting rate of 80 million counts per second) with the same lifetime accuracy of 10% and the same pixel resolution.