• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.175-178
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• 2005

TM plane-wave scattering from finite rectangular grooves in a conducting plane is systematically analyzed with the overlapping T-block method. Multiple rectangular grooves are divided into several overlapping T-blocks to obtain the fast CPU time, CAD applicability, and wide versatility. The scattered fields are obtained in simple closed forms including a fast-convergent integral.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.364-365
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• 2006

Transverse some wave was generated by T type waveguide for single wafer cleaning application T type megasonic waveguide was analyzed by acoustic pressure measurements and particle removal efficiency. Compared to conventional longitudinal waves, not like longitudinal waves, transverse waves showed changes of direction and phase which increased the cleaning efficiency.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.3033-3039
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• 2000

Mechanical properties of the materials used for transportations and industrial machinery under high stain rate loading conditions have been required to provide appropriate safety assessment to these mechanical structures. The Split Hopkinson Pressure Bar(SHPB) technique with a special experimental apparatus can be used to obtain the material properties under high strain rate loading condition. There have been many studies on the material behavior under high strain rate compressive loading compared to those under tensile loading. In this paper, mechanical properties of the aluminum alloy, Al6061-T6, under high strain rate tensile loading were determined using SHPB technique.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.268-273
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• 2000

Mechanical properties of the materials used for transportations and industrial machinery under high strain rate loading conditions are required to provide appropriate safety assessment to these mechanical structures. The Split Hopkinson Pressure Bar(SHPB) technique, a special experimental apparatus, can be used to obtain the material behavior under high strain rate loading condition. In this paper, dynamic deformation behaviors of the aluminum alloys, Al2024-T4, Al6061-T6 and Al7075-T6, under high strain rate compressive and tensile loading are determined using SHPB technique.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.3
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• pp.368-377
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• 1998

The purpose of this study was to examine theory about indoor thermal comfort-environment as well as to determine thermal sensation and physiological responses for men in summer indoor environment, under various air temperature and relative humidity, with male university students. Subjective Evaluation, Heart Rate(Electrocardiogram), Electroencephalogram(EEG) were examined. We found that comfort of people was achieved at SE $T^{*}$ 24.7$^{\circ}C$, -0.82＜PMV＜0.93, subject's clothing(0.41c1o)and the difference of skin temperature was found at the calf area as air temperature changes. At low SE $T^{*}$, heart rate was decreased and at high SE $T^{*}$, heart rate was increased but there was no change EEG(keeping $\alpha$-wave).wave).

• Journal of Korean Medicine for Obesity Research
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• v.23 no.1
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• pp.28-41
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• 2023

Objectives: This study was aimed to evaluate the hemodynamic feasibility using pulse parameters as a way to establish safe dose guidelines for herbal prescription containing Ephedra herb (Ephedra intermedia Schrenk & C.A.Mey) on weight loss, and to provide a foundation for developing evidence-based guidelines for clinical use. Methods: Forty-two volunteers were recruited to participate in a study examining the changes in pulse wave characteristics following the ingestion of Gambi-hwan, a herbal prescription containing ephedra, over a period of 4 weeks, and pulse wave measurements were taken before and after the administration. Pulse wave parameters were measured in this study using a 3-dimensional radial pulse tonometry device (DMP-Lifeplus). In addition, questionnaire, blood pressure, temperature, and body composition were also measured as secondary measures. Results: Fifteen minutes after administration of Gambi-hwan, the non-adverse event group (non-AE) exhibited a statistically significant increase in several power and pressure-related parameters, including h1, h5, systolic area, pulse area, and pulse width, while the AE group showed a trend of decreasing stroke volume and increasing Radial Augmentation Index (RAI), w, and w/t. After 4 weeks of administration, both groups exhibited significant changes in pulse rate, w/t, RAI, t3/t, stroke volume (SV), and stroke volume Index (SVI). Notably, there are significant differences between AE group and non-AE group in w/t, SV, and SVI. Conclusions: These findings suggest that pulse parameters may be a useful way to establish safe dosing guidelines for weight loss herbal prescription containing ephedra. Further research is needed to confirm these results and to develop evidence-based guidelines for clinical use.

• Journal of the Korean Institute of Oriental Medical Informatics
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• v.14 no.1
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• pp.81-106
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• 2008

The ECG which used for this paper, is analysis result from alogrisms of arrythmia, and we have studied that how we could certain Cold(寒 )type or Heat(熱) type and that Deficiency(虛) type or Excess(實)type of organs from various special diseases, and we obtained like these results. 1. we depend on our examination about Pulse(脈) because we can't discriminate arrythmia using EKG analysis instruments. 2. We obtained that Cold(寒) type diseases had wave that prolonged above normal baseline and ST wave which had downward aptitude. 3. We obtained that Heat(熱) type diseases had the fibrillation which had shortend wave that compare to normal and had downward aptitude or negative aptitude. 4. We obtained that Respiratory system (肺) diseases had wave that is within normal or is short of normal range and had much fluctuation in potential difference or trans on P wave. 5. The character of EKG which presented about diseases of gastric systems is prolonged above narmal range of wave, and the EKG had represented mixed wave with Heat(熱) type when accompany inflammatory in gastric system. 6. The wave of Blood Stasis(瘀血) type had upward aptitude of QRS wave, and the wave of anemia or blood loss type(少血 ) had downward aptitude of QRS wave, the wave which had both Cold(寒) and Heat (熱) represented mixed waves. 7. The Knotted Pulse(結脈) and Intermittent Pulse(代脈) is corresponded with sinus brady cardia, and the Swift Pulsle(疾脈) is corresponded with fibrillation. 8. We pay attention to the relations of formations about pressures pulse from formations of EMD( electromechanical dissociation ). From these results, we will have to study about EKG which using in tests of change of Parkinsons disease.

• Korean Journal of Occupational Health Nursing
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• v.29 no.2
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• pp.114-122
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• 2020

Purpose: This study aimed to identify the effect of integrated nursing using cognicise and neurofeedback on cognition and α waves among elderly individuals. Methods: This quasi-experimental single group pretest-posttest study included 29 Korean adults aged 65 years or older who participated at a senior welfare center in Y city from February to May 2019. Each integrated nursing session consisted of cognicise (10 minutes) and neurofeedback (20 minutes). Subjects participated twice a week for 10 weeks. Structured questionnaires to assess participants' general characteristics and the Korean version of the Mini-Mental Status Examination for Dementia Screening (K-MMSE-DS) were applied. Alpha waves were measured using BrainMaster. Results: Following the integrated nursing program, alpha waves improved in F3 (t=2.41, p=.023), C3 (t=3.00, p=.006), C4 (t=2.60, p=.015), P3 (t=2.43, p=.022), O1 (t=2.30, p=.029), T3 (t=3.05, p=.005), T4 (t=2.28, p=.030), T5 (t=2.91, p=.007), Fz (t=2.30, p=.029), Cz (t=2.73, p=.011), and Pz (t=2.23, p=.034). Most subjects experienced improvement in concentration after participating in the intervention. Conclusion: This study provides evidence for the use of a neuroscientific approach including brain wave measurement to improve cognitive health among community-living elderly people.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.2
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• pp.173-178
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• 2019

Recently, the types and amount of data generated, collected, and measured in IoT such as smart home, security, and factory are increasing. The technologies for IoT service include sensor devices to measure desired data, embedded software to control the devices such as signal processing, wireless network protocol to transmit and receive the measured data, and big data and AI-based analysis. In this paper, we focused on developing a gateway for interfacing heterogeneous sensor network protocols that are used in various IoT devices and propose a heterogeneous network interface IoT gateway. We utilized a OpenWrt-based wireless routers and used 6LoWAN stack for IP-based communication via BLE and IEEE 802.15.4 adapters. We developed a software to convert Z-Wave and LoRa packets into IP packet using our Python-based middleware. We expect the IoT gateway to be used as an effective device for collecting IoT big data.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.349-354
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• 2001

The present study addresses the open end correction associated with the reflection and discharge phenomena of a weak shock wave from an open end of a duct. The open end correction of the weak shock wave is investigated experimentally and by numerical computation. An experiment is made using a simple shock tube with an open end, and computation is performed to simulate the experimental flow field using the unsteady, axisymmetric, compressible, flow governing equations. The results obtained show that an open end correction should be involved for shock wave discharge and reflection problems generated from the exit of the duct with an open end baffle plate. With a baffle plate less than three times the duct diameter, it is found that the open end correction is a function of both the diameter of the baffle plate and normal shock wave magnitude. However, for a baffle plate larger than three times the duct diameter, it is independent of the baffle plate diameter. The present computations predict the results of shock tube experiment with good accuracy. A new empirical equation for prediction of the open end correction is found for the weak shock reflection and discharge phenomena occurring at the open end of the duct with and without a baffle plate.