• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.52-59
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• 2006

This paper examined the conversion of methane to hydrogen and other higher hydrocarbons using dielectric barrier discharge with AC pulse power. Two metal electrodes of a coaxial-type plasma reactor were separated by gas gap and an alumina tube. The inner electrode was located inside the alumina tube. The alumina tube was located inside the stainless steel tube, which was used as the outer electrode. Effect of feed gas composition (methane, oxygen, argon, water and helium), flow rate, applied frequency, input volt-age on methane conversion and product distribution were studied. The major products of plasma chemical reactions were ethylene, ethane, propane, buthane, hydrogen, carbon monoxide and carbon dioxide. The increment of applied voltage and the usage of inert gas as the background (helium and argon) enhanced the selectivity of hydrocarbons and methane conversion. The addition of water in the feed stream enhanced the conversion of methane and yield of hydrogen. Higher voltage leads to higher yield of $C_2H_6,\;C_3H_8,\;C_4H_{10}$ and yield or $C_2H_2\;and\;C_2H_4$ appeared highly in lower voltage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1134-1141
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• 1999

In this paper, we implement an optical code division multiple access(OCDMA) system and analyze the performance of the implemented system. In the implemented system, a transmitter encodes input data into optical pulses by using laser diode, and spreads the encoded pulses in an encoder which consists of 4 stage delay lines. The decoder which is the same structure as that of encoder delays and combines the spreaded pulses, and thus recovers the original data. At first, we discuss the auto- and cross-correlations of OCDMA signals under both environments of single user and multi-users, and then verify the simulation results with experimental results. We also evaluate the effect of a number of stages of delay line and code length on the system performance through computer simulations. As experimental results we can see that if the decoder have the same configuration as that of encoder, the peak auto-correlation characteristics can be achieved, and thus we can recover the original data from received data. As simulation results we can see that although bit error rate decreases as code length decreases or the number of stage of delay line increases, it is difficult to implement the system because the pulse width becomes narrow. From the results, we can apply CDMA technologies to optical communication networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.93-102
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• 2016

This study examined effects of the communication accompanied with music therapy on the anxiety of patients during a MRI examination. In the experiment group consisting of thirty patients and the control group consisting of thirty patients, the experiment was performed from February 1st 2014 to March 31st 2014 in hospital C located in Daegu Korea. The research design was a non-equivalent control group quasi-experimental study. The results showed that the anxiety score (VAS score) on communication with music therapy of the experimental group was significantly lower (p=.001), than that of the control group. Among the vital signs, the blood pressure was similar in both groups. On the other hand, the pulse rate of the experiment group was significantly lower (p=.001). Four categories of the physical discomfort (perspiration, facial change, change in physical posture, and change in vocal sound) did not show any statistically significant difference between the control and experiment group. Among the mental discomforts, dizziness did not have a significant difference between the experiment group and the control group, but the experimental group had significantly low fear (p=.001) and anxiety (p=.001). From the above results, communication accompanying music therapy proves is an effective alternative examination method that reduces the anxiety of patients.

• The Journal of the Korea Contents Association
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• v.11 no.6
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• pp.289-301
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• 2011

This study is a research based on the non-equivalent control group pretest-posttest design whose purpose is to examine the effects of music therapy on the anxiety of patients who take the magnetic resonance imaging(MRI) test and their feeling of discomfort during the test. "The first hypothesis that the experimental group who receive music therapy will be lower in score for anxiety during the MRI test than the control group who do not was supported because after the therapy, the experimental group was found significantly decreased in that score in comparison to the control group. "The second hypothesis that the experimental group who receive music therapy will be fewer in vital signs after the MRI test than the control group who do not" was rejected in terms of both systolic and diastolic blood pressure. But the same hypothesis was partially supported because the two groups showed a significant difference in pulse rate after the test. "The third hypothesis that the experimental group who receive music therapy will be less in the feeling of subjective discomfort during the MRI test than the control group who do not" was verified to find that the two groups were significantly different from each other in the feeling. Specifically, there was a significant difference between the two groups in only one sub-area of that feeling, that is, tension. These findings suggest that music therapy could be an alternative method which can effectively reduce the state anxiety of patients during the magnetic resonace imaging(MRI) test.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.503-512
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• 2011

Recently in HCI research, emotion recognition is one of the core processes to implement emotional intelligence. There are many studies using bio signals in order to recognize human emotions, but it has been done merely for the basic emotions and very few exists for the other emotions. The purpose of present study is to confirm the difference of autonomic nervous system (ANS) response in three emotions (boredom, pain, and surprise). There were totally 217 of participants (male 96, female 121), we presented audio-visual stimulus to induce boredom and surprise, and pressure by using the sphygmomanometer for pain. During presented emotional stimuli, we measured electrodermal activity (EDA), skin temperature (SKT), electrocardiac activity (ECG) and photoplethysmography (PPG), besides; we required them to classify their present emotion and its intensity according to the emotion assessment scale. As the results of emotional stimulus evaluation, emotional stimulus which we used was shown to mean 92.5% of relevance and 5.43 of efficiency; this inferred that each emotional stimulus caused its own emotion quite effectively. When we analyzed the results of the ANS response which had been measured, we ascertained the significant difference between the baseline and emotional state on skin conductance response, SKT, heart rate, low frequency and blood volume pulse amplitude. In addition, the ANS response caused by each emotion had significant differences among the emotions. These results can probably be able to use to extend the emotion theory and develop the algorithm in recognition of three kinds of emotions (boredom, surprise, and pain) by response measurement indicators and be used to make applications for differentiating various human emotions in computer system.

• Journal of Nutrition and Health
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• v.21 no.5
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• pp.305-316
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• 1988

The purpose of this research was to determine the relationship of the dietary nutrients to blood pressure among preschool children in Seoul and to concurrently study the effect of seasonal variance on the aforementioned relationship. The subjects of the study consisted of 203 preschool children aged four to six years. Anthropometric measurements of height, weight, pulse rate and blood pressure, urinary excretion of five cations(Na, K, Ca, P, Mg), creatinine and urea nitrogen and dietary questionaires concerning sodium, potassium calcium and phosphorus were taken during the two periods of summer(Aug. 1986)and winter(Feb, 1987). The results obtained are summarized as follows: 1) The daily urinary excretion of five cations, creatinine and urea nitrogen is summer and winter was as follows; The sodium content was 57.8 mEq in the summer and 59.4 mEq in the winter ; potassium 20.4 mEq and 23.0 mEq, respectively ; calcium, 5.5 mEq and 3.6 mEq, respectively ; and phosphorus, 27.4 mEq and 19.9 mEq, respectively. Only calcium and phosphours excretions in the urine showed significant differences per season(p<0.05). 2) The average dietary intake per day of sodium was 2349mg in the summer and 2155mg in the winter ; potassium consumption was 1425mg in the summer and 1448mg in the winter ; intake of calcium was 472mg in the summer and 500mg in the winter ; and phosphours consumption was 642mg in the summer and 634mg in hte winter. The sodium-to-potassium consumption ratio 1.6 and 1.5, respectively, in the summer and in the winter and the calcium-to-phosphorus ration was 0.7 in the summer and 0.8 in the winter. The dietary calcium intake showed significant differences between the seasons. 3) The principal source of sodium consumption among preschool children was from seasoning-including talbe salt, soy sauce and instant sauce-which accounted for higher then 45% of the sodium intake in both seasons. The main source of potassium was frutis and vegetables which accounted for 29.6% of the potassium intake in the summer and 25.7% in the winter. Milk and milk products were the primary dource of calcium(higher then 40% in both seasons) 4) In the summer, urinary phosphours levels were weakly reated to systolic blood pressures. (0.05

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.746-754
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• 2016

Smart healthcare systems, a convergent industry based on information and communications technologies (ICT), has emerged from personal health management to remote medical treatment as a distinguished industry. The smart healthcare environment provides technology to deliver vital information, such as pulse rate, body temperature, health status, and so on, from wearable devices to the hospital network where the physician is located. However, since it deals with the patient's personal medical information, there is a security issue for personal information management, and the system may be vulnerable to cyber-attacks in wireless networks. Therefore, this study focuses on a key-development and device-management system to generate keys in the smart environment to safely manage devices. The protocol is designed to provide safe communications with the generated key and to manage the devices, as well as the generated key. The security level is analyzed against attack methods that may occur in a healthcare environment, and it was compared with existing key methods and coding capabilities. In the performance evaluation, we analyze the security against attacks occurring in a smart healthcare environment, and the security and efficiency of the existing key encryption method, and we confirmed an improvement of about 15%, compared to the existing cipher systems.

• Korean Journal of Health Education and Promotion
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• v.11 no.2
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• pp.48-56
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• 1994

In order to study the factors influencing upon right medication of antibiotic for the consumers who can easily buy antibiotic from pharmacy, the study carried out questionnaires to 568 consumers who bought antibiotics from pharmacies located in Seoul And Kyung-gi do from the 1st of February, 1994 to the 28th of the same month. Materials have been analyzed with $X^-test$ of SAS, and its results are as follows. 1. Among 568 objects of this study, the group which can medicare antibiotic properly (the right use group of antibiotic) is 45.5% with 258, while the group which does not recognize correctly the use of antibiotic or does not have any information about it (the abuse group of antibiotic) is 54.6% with 310. 2. Knowledge for advantage of antibiotic the right use group has is high in comparing with that of the abuse group (p<0.001), and also in case of pregnancy, understanding for an adverse reaction of antibiotic is high (p<0.001). The right use group has had many chances to take health education (p<0.001), and the way to buy antibiotic is very safe (p<0.001). But there is no outstanding difference for recognition of an adverse reaction of antibiotic between two groups. 3. In comparing with the abuse group, the right use group keeps well taking time of antibiotics as directions (p<0.001), and keeping rate of antibiotic dosage is high (p<0.001). Also the experiences of an adverse reaction of antibiotic is low (p<0.001). 4. In comparing with the abuse group, the right use group has high educational backgrounds (p<0.001) and many experiences of the education for health promotion (p<0.001), while there is no difference in age, sex, and economic status. 5. In comparing with the abuse group, the right use group has taken antibiotic many times (p<0.001), and there are many antibiotic takers of his/her family (p<0.01). 6. In comparing with the abuse group, the right use group has made much effort not only to check blood pressure and the pulse (p<0.05) but also for food habits (p<0.05). But there is no outstanding difference in the effort to get health information and the effort for regular exercises between these two group. 7. In comparing with the abuse group, the right use group has made an exertion in buying foodstuffs (p<0.001). But there is no big difference in efforts to keep the good attitude for physical health and mental heath, and sleeping hours between these two group.

• Carbon letters
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• v.28
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• pp.31-37
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• 2018

This paper examines a simple one-step and catalyst-free method for synthesizing carbon nanoparticles from aliphatic alcohols and n-hexane with linear molecule formations by using a stable solution plasma process with a bipolar pulse and an external resistor. When the external resistor is adopted, it is observed that the current spikes are dramatically decreased, which induced production of a more stable discharge. Six aliphatic linear alcohols (methanol-hexanol) containing carbon with oxygen sources are studied as possible precursors for the massive production of carbon nanoparticles. Additional study is also carried out with the use of n-hexane containing many carbons without an oxygen source in order to enhance the formation of carbon nanoparticles and to eliminate unwanted oxygen effects. The obtained carbon nanoparticles are characterized with field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, and Raman spectroscopy. The results show that with increasing carbon ratios in alcohol content, the synthesis rate of carbon nanoparticles is increased, whereas the size of the carbon nanoparticles is decreased. Moreover, the degree of graphitization of the carbon nanoparticles synthesized from 1-hexanol and n-hexane with a high carbon (C)/oxygen (O) ratio and low or no oxygen is observed to be greater than that of the carbon nanoparticles synthesized from the corresponding materials with a low C/O ratio.

• Journal of the Korean Electrochemical Society
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• v.9 no.1
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• pp.19-28
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• 2006

The phase-shift method for determining the Langmuir, Frumkin, and Temkin adsorption isotherms ($\theta_H\;vs.\;E$) of H for the cathodic $H_2$ evolution reaction (HER) at a Pt/0.1 M KOH solution interface has been proposed and verified using cyclic voltammetric, differential pulse voltammetric, and electrochemical impedance techniques. At the Pt/0.1 M KOH solution interface, the Langmuir and Temkin adsorption isotherms ($\theta_H\;vs.\;E$), the equilibrium constants ($K_H=2.9X10^{-4}mol^{-1}$ for the Langmuir and $K_H=2.9X10^{-3}\exp(-4.6\theta_H)mol^{-1}$ for the Temkin adsorption isotherm), the interaction parameters (g=0 far the Langmuir and g=4.6 for the Temkin adsorption isotherm), the rate of change of the standard free energy of $\theta_H\;with\;\theta_H$ (r=11.4 kJ $mol^{-1}$ for g=4.6), and the standard free energies (${\Delta}G_{ads}^{\circ}=20.2kJ\;mol^{-1}$ for $k_H=2.9\times10^{-4}mol^{-1}$, i.e., the Langmuir adsorption isotherm, and $16.7<{\Delta}G_\theta^{\circ}<23.6kJ\;mol^{-1}$ for $K_H=2.9\times10^{-3}\exp(-4.6\theta_H)mol^{-1}$ and $0.2<\theta_H<0.8$, i.e., the Temkin adsorption isotherm) of H for the cathodic HER are determined using the phase-shift method. At intermediate values of $\theta_H$, i.e., $0.2<\theta_H<0.8$, the Temkin adsorption isotherm ($\theta_H\;vs.\;E$) corresponding to the Langmuir adsorption isotherm ($\theta_H\;vs.\;E$), and vice versa, is readily determined using the constant conversion factors. The phase-shift method and constant conversion factors are useful and effective for determining the Langmuir, Frumkin, and Temkin adsorption isotherms of intermediates for sequential reactions and related electrode kinetic and thermodynamic data at electrode catalyst interfaces.