• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.04a
• /
• pp.421-424
• /
• 2011

Thermal Analyses are conducted to measure various factors of a liquid fuel required for numerical analysis. Thermal Analyses are divided into two different methods of TGA (Thermo Gravimetric Analysis) and DSC (Differential Scanning Calorimetry). Non-isothermal experimental results are analyzed using by TGA. The results are filtered by a Freeman Carroll method. At the same time, chemical parameters of unknown liquid fuel, activation temperature and reaction order are measured to 6128.2 K and 1.4, respectively. Furthermore, the parameters can be obtained by various mathematical methods. It is found that tha parameters depend on the processing method.

• Journal of Electrochemical Science and Technology
• /
• v.10 no.2
• /
• pp.159-169
• /
• 2019

The activated carbon materials were prepared from waste biomass by ultrasonic assisted chemical activation method (UCA), ultrasonic assisted physical activation method (UPA) and Manganese nitrogen doped carbon (Mn/N-C). The XRD result shows the turbostatic (fully disordered) structure. The cyclic voltammetry test was done at 50 mV/s using 1M sodium sulfate and the values of specific capacitance were found to be 93, 100 and 115 F/g for UCA, UPA and Mn/N-C respectively. The power density values for the samples UCA, UPA and Mn/N-C were found to be 46.04, 87.97 and 131.42 W/kg respectively. The electrochemical impedance spectroscopy was done at low frequency between 1 to 10 kHz. The Nyquist plot gives the resistant characteristics of the materials due to diffusional resistance at the electrode-electrolyte interface. The Energy Dispersive X-Ray Spectroscopyanalysis (EDAX) analysis showed that the percentage doping of nitrogen and manganese were 3.53 wt% and 9.44 wt% respectively. It is observed from the experiment Mn/N-C doped carbon show good physical and electrochemical properties.

• Journal of International Academy of Physical Therapy Research
• /
• v.12 no.2
• /
• pp.2338-2344
• /
• 2021

Background: The therapeutic exercise method using kinesiology taping (KT) has been reported to be effective in activating the suprahyoid muscle in healthy adults. However, its applicability and effectiveness are not known to the physically vulnerable elderly. Objectives: To investigate the effects of kinesiology taping on the activity of suprahyoid muscles in community-dwelling elderly people. Design: Repeated measure design. Methods: We enrolled 23 healthy elderly adults (age range 60-75 years) with no history of neurologic disease. Participants performed five consecutive spontaneous swallowing actions at 5-second intervals under three conditions (KT with 80% stretch, placebo-KT, and non-KT. Activation of the suprahyoid muscles during swallowing in the three conditions was measured using surface electromyography (sEMG). In addition, a 0-10 numerical rating self-report scale was used to evaluate the required effort and the resistance felt during swallowing. Results: KT with 80% stretch were significantly higher in sEMG mean value, peak value, required effort, and resistance felt during swallowing compared to other two conditions (P<.05, all). KT with 80% stretch required the most effort during swallowing and, consequently, has a positive effect on increasing suprahyoid muscle activation. Conclusion: Our results could be taken into consideration in therapeutic exercise method for suprahyoid muscle in dysphagia rehabilitation.

• Journal of Information Processing Systems
• /
• v.19 no.5
• /
• pp.614-630
• /
• 2023

Dead trees significantly impact forest production and the ecological environment and pose constraints to the sustainable development of forests. A lightweight YOLOv4 dead tree detection algorithm based on unmanned aerial vehicle images is proposed to address current limitations in dead tree detection that rely mainly on inefficient, unsafe and easy-to-miss manual inspections. An improved logarithmic transformation method was developed in data pre-processing to display tree features in the shadows. For the model structure, the original CSPDarkNet-53 backbone feature extraction network was replaced by MobileNetV3. Some of the standard convolutional blocks in the original extraction network were replaced by depthwise separable convolution blocks. The new ReLU6 activation function replaced the original LeakyReLU activation function to make the network more robust for low-precision computations. The K-means++ clustering method was also integrated to generate anchor boxes that are more suitable for the dataset. The experimental results show that the improved algorithm achieved an accuracy of 97.33%, higher than other methods. The detection speed of the proposed approach is higher than that of YOLOv4, improving the efficiency and accuracy of the detection process.

• Nuclear Engineering and Technology
• /
• v.56 no.4
• /
• pp.1330-1338
• /
• 2024

Information on isotopic composition and geometric structure is necessary for identifying a true warhead. Nevertheless, such classified information should be protected physically or electronically. With a novel Hash encryption algorithm, this paper presents a Monte Carlo-based design of a neutron activation analysis verification module. The verification module employs a thermal neutron source, a non-uniform mask (physically encrypting information about isotopic composition and geometric structure), a gamma detector array, and a Hash encryption algorithm (for electronic encryption). In the physical field, a non-uniform mask is designed to distort the characteristic gamma rays emitted by the inspected item. Furthermore, as part of the Hash algorithm, a key is introduced to encrypt the data and improve the system resolution through electronic design. In order to quantify the difference between items, Hamming distance is used, which allows data encryption and analysis simultaneously. Simulated inspections of simple objects are used to quantify system performance. It is demonstrated that the method retains superior resolution even with 1% noise level. And the performances of anti-statistical attack and anti-brute force cracking are evaluated and found to be very excellent. The verification method lays a solid foundation for nuclear disarmament verification in the upcoming era.

• Nuclear Engineering and Technology
• /
• v.56 no.5
• /
• pp.1796-1802
• /
• 2024

The production cross sections of ^55,56,57Co, ^52gFe, ^52g,54Mn, ⁵¹Cr, and ⁴⁸V from the ^natFe (p,x) reactions were measured using a proton energy of 57 MeV at the Korea Multi-purpose Accelerator Complex (KOMAC) in Gyeongju, Korea. The conventional stacked-foil activation method and offline γ-ray spectroscopy were used to determine the excitation functions of proton induced nuclear reactions on iron. The measured excitation functions were compared with experimental data in literature and theoretical data from the TENDL-2021 library. The present data show generally good agreement with other experimental data, but discrepancies were found between the present data and the excitation functions of the TENDL-2021 library in the investigated energy range, except for ^56,57Co and ⁵⁴Mn.

• Nuclear Engineering and Technology
• /
• v.56 no.7
• /
• pp.2835-2841
• /
• 2024

Real-time analysis of metallic mineral grade and slurry concentration is significant for improving flotation efficiency and product quality. This study proposes an online detection method of ore slurry combining the Prompt Gamma Neutron Activation Analysis (PGNAA) technology and artificial neural network (ANN), which can provide mineral information rapidly and accurately. Firstly, a PGNAA analyzer based on a D-T neutron generator and a BGO detector was used to obtain a gamma-ray spectrum dataset of ore slurry samples, which was used to construct and optimize the ANN model for adaptive analysis. The evaluation metrics calculated by leave-one-out cross-validation indicated that, compared with the weighted library least squares (WLLS) approach, ANN obtained more precise and stable results, with mean absolute percentage errors of 4.66% and 2.80% for Fe grade and slurry concentration, respectively, and the highest average standard deviation of only 0.0119. Meanwhile, the analytical errors of the samples most affected by matrix effects was reduced to 0.61 times and 0.56 times of the WLLS method, respectively.

• Proceedings of the IEEK Conference
• /
• 2000.11b
• /
• pp.225-228
• /
• 2000

In this paper, we demonstrated an analytical description method of forward voltage drop and reverse voltage of $P^{+}N$ junction diode with <111> oriented antimony doped silicon wafer 60keV boron implantation computer simulation results. In order to make electrical activation of implanted carriers, thermal annealing are carried out by RTP method for 1min at $1000^{\circ}C$ inert gas condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.05a
• /
• pp.150-153
• /
• 1996

Polyvinylidene fluoride(PVDF) thin films are fabricated by vapor deposition method and their dielectric characteristics are investigated. At electric field near 4MV/m, a phase transition occur with polar ${\alpha}$ . In accordance to increasing temperature, the dielectric relaxation of PVOF thin films show from 70Hz to 104Hz. This result correspond to Debye's theory[1]. Activation energy of PVDP thin film is 21Kca1/mo1.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.7
• /
• pp.703-706
• /
• 1997

Response surface method was applied to the predicting optimum conditions of benzene synthesis for radiocarbon dating. The weight of carbon dioxide, the temperature of lithium container for producing acetylene and the activation temperature of catalyst which was used for the cyclization of acetylene to benzene were used as experimental factors. The yields of benzene synthesis were measured from twelve experiments which were carried out under various experimental conditions. The polynomial equation was obtained by using three experimental factors and yields. The validity of polynomial equation was confirmed by comparing the calculated yields with the experimental ones.