• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.922-924
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• 1998

In this paper, an optical fiber sensor(OF sensor) utilizing the principal of Mach-Zehnder interferometer were proposed to detect the partial discharge signals in insulating oil. At first the AC breakdown signals were detected to check the response of the OF sensor. The detected signals from OF sensor was consistent with that from current probe. After the response checking, simultaneous measurements and continuous recording were made of electrical and the OF sensor signals from partial discharge(PD) produced by IEC(b) electrode system immersed in insulating oil. The continuous recording made it possible to extract basic quantities of PD from the OF sensor signals, such as pulse phase and pulse amplitude distribution. Through the signal analysis, the absolute peaks of the OF sensor PD signal was found to be increased with the amplitude of electrical signals, and these results mean that there is a strong correlation between OF sensor and electrical PD signals. It was demonstrated that the OF sensor in this research had a possibility to detect the PD signals in power apparatus.

• Annals of Clinical Neurophysiology
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• v.1 no.1
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• pp.26-30
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• 1999

Background : The origin of P300 was still on debate nbut thought to be in the frontal, temporal or parietal lobe. As the transcranial doppler ultrasonography(TCD) gives us and opportunity to observe hemodynamic chaged dynamically and the middle cerebral artery feeds these ares of the hemisphere, we observed the change of mean flow velocity of MCA during the event related potential test(ERP) to determine the role of these structures in P300 generation. Method : Twenty normal subjects(male : 13, age : 24-29 years) performed ERP. An auditory oddball pardigm was used to elicit the ERPs. TCD examination was performed with 2-MHz probe monitoring the left MCA(Transscan, EME). After signal identification and adjustments to maximize the Doppler signal strength, the probe was mechanically locked during the monitoring. The changes of blood flow velocity of the left middle cerebral artery(MCA) induced by cognitive demands were monitored. The measurement of the meal flow velocities(MFV) of MCA were made while the subjects were prior to, during, and after ERP. We recorded the MFVs during ERP. Statistical analysis was performed using t-tests with SPSS-PC for windows release 6.0. Results : All subjects showed a relative increase in MFV of MCA during the task. The mean rise was about 3.2-4.2%(p <0.05). Although TCD does not measure absolute values of regional cerebral blood flow(rCBF) or absolute rCBF changes, changes of flow velocity can reflect relative rCBF changes. Conclusions : The generation site of P300 still remains unclear but the neocortical, thalamic and limbic region and temporal-parietal cortex have been proposed. The MCA supplies these anatomical structures. The Changes of flow veolocity of MCA during the ERP test suggest that the some part of the brain fed y the MCA activate of the temporal lobe or parietal lobes, we can deduce that some parts of brain fed by the MCA participate in the generation of P300.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.249-257
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• 2017

Filtering the data for travel time records obtained from DSRC probes is essential for a better estimation of the link travel time. This study addresses the major deficiency in the performance of TRANSGUIDE in removing anomalous data. This algorithm is unable to handle unstable traffic flow conditions for certain time intervals, where fluctuations are observed. In this regard, this study proposes an algorithm that is capable of overcoming the weaknesses of TRANSGUIDE. If TRANSGUIDE fails to validate sufficient number of observations inside one time interval, another process specifies a new validity range based on the median absolute deviation (MAD), a common statistical approach. The proposed algorithm suggests the parameters, ${\alpha}$ and ${\beta}$, to consider the maximum allowed outlier within a one-time interval to respond to certain traffic flow conditions. The parameter estimation relies on historical data because it needs to be updated frequently. To test the proposed algorithm, the DSRC probe travel time data were collected from a multilane highway road section. Calibration of the model was performed by statistical data analysis through using cumulative relative frequency. The qualitative evaluation shows satisfactory performance. The proposed model overcomes the deficiency associated with the rapid change in travel time.

• Physical Therapy Korea
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• v.10 no.1
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• pp.15-27
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• 2003

Therapeutic ultrasound is commonly applied for deep heating in physical therapy setting. However, it is difficult to determine the exact application dosage and to confirm the immediate heating effect. Microwave Radio-Thermometer (MRT) can measure the temperature by the electromagnetic energy in the microwave region of the object that emits above absolute zero temperature. MRT was used for early diagnosis of breast cancer since it was not harmful, non-invasive, and non-ionizing to the human body. The purposes of this study were to investigate how accurately 1.1 GHz RTM (RES Ltd. Russia) measures the change of average temperature in the tissue, and to determine the depth of temperature change measurement. Therapeutic ultrasound was applied (continuous wave for 5 minutes, 1 MHz, intensity of 1.5 $W/cm^2$ [in vitro] and 1.0 $W/cm^2$ [in vivo]) in four different conditions: (1) 30 cases of in vitro specimen of pork, (2) 30 cases of in vitro specimen of pork ankle joint, (3) 10 cases of in vivo canine thigh, and (4) 30 cases of in vivo human body. Intraclass Correlation Coeffients (ICC[3,1]) between average needle probe thermometer below surface and MRT temperature was revealed as followed: (1) Before ultrasound application ICCs ranges above .8 in specimen of pork (15 mm underneath the skin) and above .82 in specimen of pork ankle joint (10~30 mm underneath the skin). (2) After ultrasound application ICCs ranges above .7 in both specimens of pork and pork ankle joint. (3) Before ultrasound application ICCs ranges above .8 in canine thigh (20 mm underneath the skin). (4) After ultrasound application ICCs ranges above .82 in canine thigh. The temperature of the human body increased significantly with the mean of $15^{\circ}C$ in muscle tissue and with the mean of $3.5^{\circ}C$ in joint (p<.00). It was revealed that the average depth of temperature measurement of the tissue by MRT was in between 10 and 35 mm, and determined that the proper temperature measurement band was $36.5{\sim}37.0^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.390.1-390.1
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• 2016

The present work explains the interfacial energetics of all oxide transparent photodiodes. The optical, structural and morphological of copper oxides were systematically analyse by UV-Visible spectrometer, X-Ray diffraction, Raman spectroscopy, Scanning electron microscopy (SEM) and Atomic force microscopy measurements (AFM). The UV-Visible result exhibits optical bandgap of Cu2O and CuO as 2.2 and 2.05 eV respectively. SEM and AFM result shows a uniform grain size distribution in Cu2O and CuO thin films with the average grain size of 45 and 40 nm respectively. The results of Current-Voltage and Kelvin probe force microscope characteristics describe the electrical responses of the Cu2O/ZnO and CuO/ZnO heterojunctions photodiodes. The obtained electrical response depicts the approximately same knee voltages with a measurable difference in the absolute value of net terminal current. More over the present study realizes the all oxide transparent photodiode with zero bias photocurrent. The presented results lay the template for fabricating and analysing the self-bias all oxide transparent photodetector.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.177-180
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• 2008

Laser induced fluorescence studies of hydrogen atom using four wave mixing technique are reported for the photodissociation of CH4 and its isotopomers at Lya (121.6 nm). The source of dissociating and probe radiation is one and the same (delay time??20 nsec). The average translational energy of ejected hydrogen atoms (50 Kcal/mol) reveals that CH4 + hn??CH3 + H(2S) and CH4 + hn??CH2(a1A1) + H2(1Sg) are the main dissociation processes. The absolute quantum yield for CH4 and CD4 are the same, FH(CH4) = FD(CD4) = 0.31 0.05. If one divides the experimental H/D ratios from the isotopomers CH3D, CH2D2, CHD3 by the isotopic H/D ratios, a value 2 is obtained in all three cases. Overall, the heavier D atoms are more likely than the H atoms to remain attached to the carbon atom.

• YAKHAK HOEJI
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• v.49 no.2
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• pp.115-121
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• 2005

In this study, the performance of a portable NIR system and a FT NIR spectrometer were compared to determine water content of hairless mouse skin. The stratum corneum parts wer e separated from the epidermal tissues by trypsin solution. NIR diffuse reflectance spectra of hairless mouse skin were acquired using a fiber optic probe. In the near infrared, water molecules show two clear absorption bands at 1450 nm from first overtone of O-H stretching and 1940 nm from the combination involving O-H stretching and O-H deformation. It was found that the variations of O-H absorption band according to water content. Partial least squares regression (PLSR) was applied to develop a calibration model. The PLS model showed a good correlation between NIR predicted value and the absolute water content of separated hairless mouse skin, in vitro. For both the portable and the FT NIR spectrometer, These studies showed the possibility of a rapid and nondestructive skin moisture measurement using NIR spectroscopy. The portable NIR spectrometer with a photodiode arrays-microsensor could be more rapidly applied for the determination of water content with comparable accuracy with the performance of a FT spectrometer .

• Korean Institute of Interior Design Journal
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• v.17 no.3
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• pp.68-76
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• 2008

This study investigated composition elements and estimation of image in lobby from user viewpoint that is the central space of local cultural institution, and spectator mainly utilizes. Progress process of study develops investigation device including literature investigation, professional panel and lobby space image measurement tool through on-the-spot probe and, executed supporting research to spectator. As the result of the study, first, lobby space image exerts absolute effect to local cultural institution image-building, and is grasped on constituent that floor, ceiling, entrance and lighting and decoration is important in image-building of lobby space. Second, the image of the important lobby space was grasped in order of convenient image(M = 3.98) bright image(M = 3.87), and cozy image(M = 3.80). Third, the results on investigating semantic structure of the lobby image, emotional factor, styling factor, spatial factor, and peculiar factor are composed of important factors that decides image of lobby space. Fourth, as the result of image analysis for lobby space, the degree of satisfaction for the local cultural institution was entirely low against the importance. In particular, the image for convenience, individuality, locality and dignity was not sufficient in all the three places. Therefore, lobby design of local cultural institution shall also suggest more various lobby space image from culture oriented viewpoint.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.470-470
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• 2010

Negative ions are generated in fusion edge plasmas, material processing plasmas, ionospheric plasmas. Analytic formulas for the deduction of the absolute density of negative ions was given by using the current-voltage(IV) characteristics of two electric probes at two different pressures [1], and negative ion density has been measured by one electric probe using the current-voltage characteristics of three different pressures [2]. Ratios of ion and electron saturation currents and electron temperatures and sheath areas of different pressures are usually incorporated into two equations with two unknowns for the negative ion density. In the previous publications, the sheath factor(sheath area, sheath density, sheath velocity) and effective masses of background ions with different pressures are qualitatively incorporated for the deduction of negative density. In this presentation, the quantitative and detailed relation of negative ion density with sheath factor and effective masses are going to be given. The effect of these parameters on the change of IV characteristics will be addressed.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.135-142
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• 1998

The purpose of the present study was to evaluate the effect of incisor protrusion on the mucogingival parameters including the width of attached gingiva. Thirty-seven young adults with lower anterior crowding were selected for this study. From the study model, the degrees of relative and absolute protrusions were measured for each lower incisor. Clinical non height, the width of keratinized gingiva, probing depth and the width of attached gingiva were measured with digital vernier calipers and Florida Probe System. Through comparing the difference of the above measurements between protruded and non-protruded incisors, and correlation analysis between each measurement, following results were obtained: 1. The protruded incisor showed narrow width of keratinized and attached gingiva comparing to non-protruded incisor. 2. The protruded incisor showed greater clinical crown height comparing to non-protruded side while there was no difference in the probing depth between protruded and non-protruded side. 3. The difference in the width of attached gingiva between protruded and non-protruded incisors showed higher significance in the lateral incisor than in the central incisor. 4. The degree of relative protrusion showed higher correlation with the width of attached gingiva than the degree of absolute protrusion. 5. Clinical crown height showed higher correlation with the width of attached gingiva than the degree of protrusion.