• Journal of Korean Physical Therapy Science
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• v.2 no.4
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• pp.771-778
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• 1995

The purpose of this study was to determine the effects of linear polarized near-infrared ray radiation on experimental pain threshold in healthy adult subjects. Thirty healthy adult subjects were divided into 5 groups: 1) group 1, super lizer radiation at 0 % ; 2) group 2, super lizer radiation at 10 % ; 3) group 3, super lizer radiation at 20 % ; 4) group 4, super lizer radiation at 40 % ; 5) group 5, super lizer radiation at 80 %. The polarized near-infrared ray radiation was applied on LI 4 point of subject's right hand at a fixed time for 30 second. Experimental pain threshold were measured with electrical current on the right hand at 5 intervals for each radiation: 1) pretreat; 2) posttreat ; 3) posttreat of 1/2 hr ; 4) posttreat of 1 hr ; and 5) posttreat of 2 hrs. Data were analyzed using analyses of variance with repeated measures for pain threshold. No significant interaction between power output and time for pain threshold was found. Significant effects of power output and time for experimental pain threshold were found. Significant increase was noted in experimental pain threshold in group 4 and group 5 at posttreat, posttreat of 1/2, 1 hr and 2 hrs as a result of the applications of the polarized near-infrared ray radiation. This study indicate that polarized near-infrared ray radiation with above 40 % of power output increases pain threshold, thus possibly increasing options in choosing radiation output for treating pateint with pain. Further study is needed to compare the effects of these radiation in patients with clinical pain.

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.219-225
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• 2007

This investigation was carried out to evaluate the effect of pain control temporomandibular disorders with clinical application of capsaicin cream. 20 healthy subjects without systemic diseases were measured in current perception threshold and pain tolerance threshold with $Neurometer^{(R)}$ CPT/C (Neurotron, Inc. Baltimore, Maryland, USA) after cold pack, 0.025% capsaicin and 0.075% capsaicin cream application. The obtained results were as follows : 1. The current perception threshold of C-fiber was significantly higher to the baseline on. There were significantly increased in C- fiber current perception threshold of 0.025% capsaicin cream and 0.075% capsaicin cream application comparison to cold pack. 2. There was significantly increased in pain tolerance threshold of cold pack and 0.075% capsaicin application comparison to one of baseline as $A{\beta}$-fiber, There was significantly higher after cold pack and 0.025% capsaicin cream application than baseline as $A{\delta}$-fiber. In C-fiber case, 0.025% capsaicin application's was significantly increased than baseline one. 3.There were significantly higher C-fiber of 0.075% capsaicin application than baseline in visual analogue scale marking pain level of pain tolerance threshold.

• Journal of Acupuncture Research
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• v.19 no.3
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• pp.77-87
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• 2002

Like acupuncture, magnetic therapy has been known to yield effectiveness when it is applied to relieve from fatigue, musculoskelectal diseases, sore sites, rheumatic arthritis and chronic pain syndromes. However, combined application of acupuncture and magnet has not yet been studied. This study is designed to investigate effectiveness of acupuncture therapy when in the magnetic field for the pain relief. Magnetic field was made by magnetic ring ($7{\psi}{\times}2.3{\psi}{\times}1.5mm$). Twenty-one male swimmers with latent muscular pain at the GB21 area in the university course of physical education in Daegu were chosen and divided into three groups; 1) acupuncture treatment group (n=7), 2) acupuncture treatment with iron ring group (n=7), 3) acupuncture treatment with magnetic ring group (n=7). Manual Acupuncture was given to the GB21 point for 20 minutes. The degree of pressure pain threshold (PPT, $kg/cm^2$) in GB21 was measured with algometer. Before acupuncture treatment, the PPT values were $6.08{\pm}1.69$, $6.39{\pm}1.72$ and $5.59{\pm}1.11$ in acupuncture treatment group, acupuncture treatment with iron ring group, acupuncture treatment with magnetic ring group, respectively. After acupuncture treatment, the PPT values were $6.48{\pm}2.33$, $6.31{\pm}1.31$ and $6.59{\pm}1.80$, respectively. Pressure threshold was significantly increased in the acupuncture treatment with magnetic ring group compared to the other groups. Based on these results, acupuncture treatment with magnetic ring produced better effects on pain threshold, and these effects can be considered to be associated with the currents or voltages induced by the acupuncture needle and magnetic ring at present.

• Korean Journal of Remote Sensing
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• v.29 no.6
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• pp.645-655
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• 2013

As one of segmentation techniques for Synthetic Aperture Radar (SAR) image with oil spill, we applied a bimodal histogram method to discriminate oil pixels from non-oil pixels. The threshold of each moving window was objectively determined using the two peaks in the histogram distribution of backscattering coefficients from ENVISAT ASAR image. To reduce the effect of wind speed on oil spill detection, we selected ASAR image which satisfied a limit of wind speeds for successful detection. Overall, a commonly used adaptive threshold method has been applied with a subjectively-determined single threshold. In contrast, the bimodal histogram method utilized herein produces a variety of thresholds objectively for each moving window by considering the characteristics of statistical distribution of backscattering coefficients. Comparison between the two methods revealed that the bimodal histogram method exhibited no significant difference in terms of performance when compared to the adaptive threshold method, except for around the edges of dark oil spots. Thus, we anticipate that the objective method based on the bimodality of oil slicks may also be applicable to the detection of oil spills from other SAR imagery.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.505-512
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• 1988

Since the propagation of a short fatigue crack is directly related to the large crack which causes the fracture of bulk specimen, the detailed study on the propagation of the short crack is essential to prevent the fatigue fracture. However, a number of recent studies have demonstrated that the short crack can grow at a low applied stress level which are predicted from the threshold condition of large crack. In present study, the threshold condition for the propagation of short fatigue crack is examined with respect to the microstructure and cyclic loading history. Specimens employed in this study were decarburized eutectoid steels which have various decarburized ferrite volume fraction. Rotating bending fatigue test was carried out on these specimens with the special emphasis on the '||'&'||'quot;critical non-propagating crack length.'||'&'||'quot; It is found that the reduction of the endurance limit of their particular microstructures can be due to the increase of the length of critical non-propagating crack, and the quantitative relationship between the threshold stress .DELTA. .sigma. $_{th}$ and the critical non-propagating crack length Lc can be written as .DELTA. .sigma. $_{th}$, Lc=C where m, C is constant. Further experiments were carried out on the effect of pearlitic structure and cyclic loading history on the length of critical non-propagating crack. It is shown that the length of critical non-propagating crack is closely related to both pearlite interlamellar spacing and cyclic loading history.ory. cyclic loading history.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9C
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• pp.720-724
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• 2008

Channel estimation in OFDM systems is usually carried out in frequency domain based on the least-squares (LS) method and the minimum mean-square error (MMSE) method with known pilot symbols. The LS estimator has a merit of low complexity but may suffer from the noise because it does not consider any noise effect in obtaining its solution. To enhance the noise immunity of the LS estimator, we consider estimation noise in time domain. Residual noise existing at the estimated channel coefficients in time domain could be reduced by reasonable selection of a threshold value. To achieve this, we propose a channel-estimation method based on a time-domain threshold which is a standard deviation of noise obtained by wavelet decomposition. Computer simulation shows that the estimation performance of the proposed method approaches to that of the known-channel case in terms of bit-error rates after the Viterbi decoder in overall SNRs.

• Journal of the Korean Data and Information Science Society
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• v.17 no.3
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• pp.889-904
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• 2006

Our purpose is to ascertain, if possible, whether atomic bomb survivors with cataracts and epilation were more radiosensitive than those survivors with cataracts but without epilation. A major ophthalmologic survey was conducted in Hiroshima and Nagasaki in 1963-64. At that time, 2125 individuals were examined. Among these individuals, estimated eye organ doses, based on the DS86 dosimetry system, and information on the occurrence of epilation within the first 60 days following the bombings are available on 1742. In the analysis of these data we have assumed that each individual represents a sample of one from a binomial distribution, and that the occurrence of cataracts and epilation are independent biological phenomena. We got following results. The threshold for cataract induction and its 95% confidence limits have been estimated from data on the occurrence of cataract and epilation. Among the 1742 study subjects, 40 had both cataracts and severe epilation. The estimated threshold based on these cases is 0.98 sievert(Sv), with 95% lower and upper confidence bounds of 0.72, and 1.32 Sv, respectively, and is highly statistically significant. Among the 27 cases of cataracts where severe epilation was not reported, the estimated threshold is 1.74 Sv with 95% lower and upper confidence bounds of 1.21 Sv, and "not estimable". The difference between these two estimates is not statistically significant although the effect of dose is highly significant in both instances. The potential importance of biases in the DS86 dose estimates is discussed. The difference between the threshold estimated from cataract cases with epilation and that from cases without epilation is not statistically significant at the 5% or 10% level, and thus affords no support for the notion of increased radiosensitivity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.1
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• pp.44-49
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• 2018

This study analyzed the Vulnerability of Network Communication devices when IEMI is coupled with the Network System. An Ultra Wide Band Generator (180 kV, 700 MHz) was used as the IEMI source. The EUTs are the Switch Hub and Workstation, which are used to configure the network system. The network system was monitored through the LAN system configuration, to confirm a malfunction of the network device. The results of the experiment indicate that a malfunction of the network occurs as the electric field increases. The data loss rate increases proportionally with increasing radiating time. In the case of the Switch Hub, the threshold electric field value was 10 kV/m for all conditions used in this experiment. The threshold point causing malfunction was influenced only by the electric field value. The correlation between the threshold point and pulse repetition rate was not found. However, in case of the Workstation, it was found that as the pulse repetition rate increases, the equipment responds weakly and the threshold value decreases. To verify the electrical coupling of the EUT by IEMI, current sensors were used to measure the PCB line inside the EUT and network line coupling current. As a result of the measurement, it can be inferred that when the coupling current due to IEMI exceeds the threshold value, it flows through the internal equipment line, causing a malfunction and subsequent failure. The results of this study can be applied to basic data for equipment protection, and effect analysis of intentional electromagnetic interference.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.28 no.3
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• pp.51-59
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• 2022

Background: This study aimed to investigate the effect of mobilization with movement (MWM) applied to the ankle joint, on the craniovertebral angle (CVA), pressure pain threshold, and neck disability index (NDI) in asymptomatic adults with a forward head posture (FHP). Methods: A total of 32 subjects with FHP were assigned to either the MWM group (N=16) or the cranio-cervical flexion exercise (CCFE) group (n=16). The CVA, pressure pain threshold and NDI were measured before and 4 weeks after the intervention. Results: A significant improvement in the CVA was observed in the MWM group (p<.05), whereas no significant changes (p>.05) were observed in the CCFE group. Both groups showed significant differences in the pressure pain threshold and NDI before and after the intervention (p<.05). Conclusion: The results of the study suggest that MWM applied to the ankle joint can effectively improve the CVA, pressure pain threshold, and NDI of adults with a forward head posture. Based on this study, the ankle MWM technique for dorsiflexion can be used as an objective research method for additional studies targeting FHP patients in the future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.169-172
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• 2000

A-Si:H and poly-Si TFT characteristics were investigated using an inverted staggered type TFT. The poly-Si films were achieved by various anneal techniques ; isothermal, RTA, and excimer laser anneal. The TFT on as-grown a-Si:H exhibited a low field effect mobility, transconductance, and high gate threshold voltage. Some films were annealed at temperatures from $200^{\circ}C$ to $1000^{\circ}C$. The TFT on poly-Si showed an improved $I_{on}/I_{off}$ ratio of $10^6$, reduced gate threshold voltage, and increased field effect mobility by three orders. Inverter operation was examined to verify logic circuit application using the poly-Si TFTs.