• Clean Technology
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• v.13 no.1 s.36
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• pp.64-71
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• 2007

The selection of a suitable adsorbent for removing organic sulfur compounds tetrahydrothiophene (THT) and t-butylmercaptan (TBM) from natural gas has been carried out. The saturation adsorption capacity for the sulfur compounds were determined by pulse adsorption method for a group of nanoporous materials, including Na-Y, Na-ZSM-5, Na,K-ET(A)S-10, Na-Mordenite, Na,K-Clinoptitolite, Ti/MCM-41, Ti/SBA-15 and amorphous titanosilicates. Among the materials tested, Na-Y and Na,K-ET(A)S-10 zeolites showed high adsorptive capacities for THT and TBM. The saturation capacity for THT on Na,K-ETS-10 was comparable with that on Na-Y zeolite, which is well known as an effective adsorbent. The capacity and adsorptivity for THT and TBM on Na,K-ETAS-10 were improved by an increase in crystallinity of Na,K-ETAS-10. An investigation of the competitive adsorption between THT and TBM from the breakthrough test using a simulated natural gas indicates that Na,K-ETS-10 selectively adsorbs THT. The breakthrough capacity for THT on Na,K-ETS-10 was 1.19 mmol/g. The results show that the high adsorption performance of Na.K-ETS-10 and Na,K-ETAS-10 is due to the highly exchanged cations in the zeolitic structure which exhibit the strong electrostatic interactions with organic sulfur compounds and their wide pore nature.

• Journal of the Korea Concrete Institute
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• v.20 no.4
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• pp.451-458
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• 2008

The near-fault ground motion (NFGM) is characterized by a single long period velocity pulse of large magnitude. NFGM's have been observed in recent strong earthquakes, Izmit Turkey (1999), Kobe Japan (1995), Northridge USA (1994), etc. These strong earthquakes have caused considerable damage to infrastructures because the epicenter was close to the urban area, called as NFGM. Extensive research for the near-fault ground motion (NFGM) have been carried out in strong seismic region, but limited research have been done for NFGM in low or moderate seismic regions because of very few records. The purpose of this study is to investigate and analyze the effect of near-fault ground motions on reinforced concrete (RC) bridge piers with lap-spliced longitudinal reinforcing steels. The seismic performance of four RC bridge piers under near-fault ground motions was investigated on the shake table. In addition, a RC bridge pier is subjected to pseudo-dynamic loadings. Test results showed that large residual displacements were observed in RC bridge piers under NFGM. RC specimens on the shake table failed at relatively low displacement ductility, compared with the displacement ductility of RC bridge pier subjected to pseudo-dynamic loadings.

• Resources Recycling
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• v.26 no.6
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• pp.73-83
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• 2017

Used small household appliances have a wide variety of product types and component materials, and contain high percentage of black plastics. However, they are not being recycled efficiently as conventional sensors such as near-infrared ray (NIR), etc. are not able to detect black plastic by types. In the present study, an automatic sorting system was developed based on laser-induced breakdown spectroscopy (LIBS) to promote the recycling of waste plastics. The system we developed mainly consists of sample feeder, automatic position recognition system, LIBS device, separator and control unit. By applying laser pulse on the target sample, characteristic spectral data can be obtained and analyzed by using CCD detectors. The obtained data was then treated by using a classifier, which was developed based on artificial intelligent algorithm. The separation tests on waste plastics also were carried out by using a lab-scale automatic sorting system and the test results will be discussed. The classification rate of the radial basis neural network (RBFNNs) classifier developed in this study was about > 97%. The recognition rate of the black plastic by types with the automatic sorting system was more than 94.0% and the sorting efficiency was more than 80.0%. Automatic sorting system based on LIBS technology is in its infant stage and it has a high potential for utilization in and outside Korea due to its excellent economic efficiency.

• Child Health Nursing Research
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• v.5 no.3
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• pp.281-291
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• 1999

The purpose of this study was to compare the sleep characteristics between the prone and the supine position in healthy newborns. The 48 newborns were observed in the prone position and the supine position respectively on the 2nd day after birth. The data were collected from January to May, 1999. The state of a newborn was classified and categorized to 6 states (deep sleep. light sleep, drowsy, quiet alert, active alert, crying) by Barnard. The movements of eyes, face and extremities, pulse and arterial oxygen were observed and recorded continuously from the start of sleep after feeding until the time of being woken for the next feeding by a trained nurse The data was analyzed by using paired t-test. The results of this study were as follows; 1. There was no significant difference in the length of sleeping time between the prone and the supine position. 2. There was no significant difference in the length and frequencies of each states(deep sleep, light sleep, drowsy, quiet alert, active alert, crying) between the prone and the supine position But the frequency of light sleep in the supine position was significantly higher than that of the prone position. 3 There was no significant difference In the numbers or eyes movements between the prone and the supine sleep position. But the amount of facial and extremity movement in the supine position was significantly higher than those in the prone position 4. There was no significant difference in the arterial oxygen content between the prone and the supine sleep position. 5. There was no significant difference in the heart rates between the prone and the supine sleep position. The above results indicated that the newborns in the prone Position moved less and slept deeper than those in the supine position. though there was no difference in the length of sleep or arterial oxygen content between the prone and the supine sleep Position. But. Nurses and mothers should consider the relationship between the sleep Position and SIDS suggested by previous researches. The infant's 'awakening' during sleep is a normal process and rather valuable because it can provide an opportunity to promote a stronger relationship between mother and baby. So, It is suggested that the supine sleep position is better than the prone sleep position for infants.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2280-2288
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• 2014

The conventional dimming control methods of LED (Light-emitting dioades) include Analog, PWM (Pulse Width Modulation), and FM (Frequency Modulation) Control. Analog dimming is controlled by adjusting forward current of Power LED. Although Analog dimming is possible to control linearly the brightness levels on a whole range (0%~100%), it comes into existence a variation of wavelength by changing the Power LED's forward current. PWM dimming has achieved by varying in duty of full current flowing to the Power LED. Generally, PWM dimming doesn't make variation of wavelength but have difficulty with adjusting the linear brightness level between 0% and 10%. FM dimming method is on the same wavelength as PWM dimming, however, it has problem of flickering at low level of dimming. This paper propose a efficient dimming control method of Power LED in order to overcome the disadvantages of the above mentioned methods. We apply to Analog method in low level of dimming control and use PWM method in dimming range from 10% to 100%. For the experiment, we design and implement a circuit and test the proposed method. Consequently, we can control the linear brightness of Power LED across the whole range and get the constant wave at different dimming level. The experimental results show the benefits of the proposed method.

• The Korean Journal of Physiology
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• v.2 no.2
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• pp.11-20
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• 1968

Maximal oxygen uptake was measured in thirty-three secondary school girls by means of the treadmill test. Eighteen middle school girls aged 14.0 (range: $13.0{\sim}15.9$) years and fifteen high school girls aged 16.9 (range: $16.0{\sim}18.0$) years served as subjects. Maximal treadmill run lasted for 2 minutes and 20 seconds and the expired air was collected in a Douglas bag through a J-valve during the last one minute period. In general, absolute values of various measurements in the high school girls were greater than those of the middle school girls. When values were expressed on the body weight or lean body weight basis, however, work capacity of middle school girls was superior to that of the high school girls. The detailed results are as follows: 1. In middle school girls maximal oxygen uptake was 1.78 l/min., 47.4 ml/kg body weight, 12.3 ml/cm body height, and 61.7ml/kg lean body mass. In high school girls maximal oxygen uptake was 1.93 l/min., 39.7ml/kg body weight, 12.3 ml/cm body height, and 51.2 ml/kg LBM. Although the absolute value of maximal oxygen uptake was greater in high school girls than in middle school girls, values expressed on the body weight basis showed the reverse trend, namely, values of the middle school girls was greater than those of the high school girls. 2. The ratio of maximal to resting oxygen uptake was 8.8 in the middle school girls and was 10.2 in the high school girls. 3. Maximal pulmonary ventilation in the middle school girls was 55.3 l/min. and 66.1 l/min. in the high school girls. The ratio of maximal to resting pulmonary ventilation was 10.2 in the middle school girls and 10.1 in the high school girls. 4. The correlation between body weight and maximal oxygen uptake was relatively high, namely, r=0.79 both in middle and high school girls. The correlation coefficient between body weight and maximal pulmonary ventilation was a little less that of between maximal oxygen uptake and showed a value of r=0.60 both in middle and high school girls. The lean body mass was a poor reference of maximal oxygen uptake or maximal pulmonary ventilation as compared to body weight. The correlation between maximal oxygen uptake and maximal pulmonary ventilation was high and the coefficient of correlation in middle school girls was 0.927 and in high school girls it was 0.856. 5. Maximal ventilation equivalent was 30.9 liters in middle school girls and 33.9 liters in high school girls. This indicated that no hyperventilation was induced during the maximal of oxygen uptake exercise period as related to the maximal oxygen uptake. 6. Heart rate reached to the peak value within 1.5 minutes after beginning of maximal oxygen uptake run and remained at the same peak plateau level throughout the entire running period. Heart rate decreased steeply on cessation of running and subsided slowly thereafter. The maximal heart rate was 184 beat/min. in middle school girls and 189 beat/min. in high school girls. 7. Maximal oxygen pulse was 9.4 in middle school girls and 9.9 ml/beat in high school girls.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2331-2338
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• 2014

The HEMP threat may have acquired new, and urgent, relevance as the proliferation of nuclear weapons and missile technology accelerates of the North Korea, for example, is assessed as already having developed few atomic weapons, and is on the verge of North Korea already has missiles capable of delivering a nuclear warhead against South Korea. ITU K.78, K81 and IEC recommended its counter-measuring for the industrial facilities with navigation and sailing facilities in order to obviate the all of processor equipped system malfunctions from the EMP/HEMP but its simulation must only be done by the computer simulation which had studied on the 1960-1990 years USA/AFWL papers. This result has a significant activities to the South Korea being under the North Korea threat because all of HEMP related products was strongly limited for export. The HEMP cord which was developed newly by the KTI including the HEMP generation & propagation analysis, optimal shelter design tool, essential EM energy attenuation in multi-layered various soils and rocks and HEMP filter design tool. Especially, the least square fitting method was adopted to analysis for the EM energy attenuation in the soils and rocks because it has a various characteristics based on the many times field test reports.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.267-274
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• 2019

To investigate the effect of high-intensity interval training (HIIT) on the outcomes of cardiac rehabilitation(CR) in elderly and younger patients with myocardial infarction(MI). Of the MI patients who received hospital-based CR from 2015 to 2017, we retrospectively reviewed the medical records of the patients who continued follow-up through the outpatient clinic. A total of 39 patients (20 elderly patients (${\geq}60year$($64.1{\pm}3.6$)) and 19 younger patients (< 60 year($55.6{\pm}2.3$)) was included in this study. The HIIT program was composed of 10 minutes of warm-up, 30 minutes of interval aerobic exercise, and 10 minutes of cool down. The aerobic exercise based on their initial exercise tolerance test outcome consisted of 3-minute usual intensity phase (60-70% of heart rate/VO2 reserve) and 4-minute of high-intensity phase (70-90% of heart rate/VO2 reserve). Exercise capacity was measured by exercise tests before and after hospital- based CR. Before CR, elderly group had a significantly lower exercise capacity in Exercise time, peak VO2, METs, Anaerobic threshold, VEmax, 02pulse than younger group. Both group showed similar improvement of cardiopulmonary exercise capacity after CR. And HIIT is safe and effective in elderly patients. It is considered necessary to further expansion for the participation of high intensity interval training in elderly patients.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1110-1118
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• 2018

Objective: To perform a meta-analysis to quantitatively assess functional magnetic resonance imaging (MRI) in the diagnosis of locally recurrent prostate cancer. Materials and Methods: A comprehensive search of the PubMed, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews was conducted from January 1, 1995 to December 31, 2016. Diagnostic accuracy was quantitatively pooled for all studies by using hierarchical logistic regression modeling, including bivariate modeling and hierarchical summary receiver operating characteristic (HSROC) curves (AUCs). The Z test was used to determine whether adding functional MRI to T2-weighted imaging (T2WI) results in significantly increased diagnostic sensitivity and specificity. Results: Meta-analysis of 13 studies involving 826 patients who underwent radical prostatectomy showed a pooled sensitivity and specificity of 91%, and the AUC was 0.96. Meta-analysis of 7 studies involving 329 patients who underwent radiotherapy showed a pooled sensitivity of 80% and specificity of 81%, and the AUC was 0.88. Meta-analysis of 11 studies reporting 1669 sextant biopsies from patients who underwent radiotherapy showed a pooled sensitivity of 54% and specificity of 91%, and the AUC was 0.85. Sensitivity after radiotherapy was significantly higher when diffusion-weighted MRI data were combined with T2WI than when only T2WI results were used. This was true when meta-analysis was performed on a per-patient basis (p = 0.027) or per sextant biopsy (p = 0.046). A similar result was found when $^1H$-magnetic resonance spectroscopy ($^1H$-MRS) data were combined with T2WI and sextant biopsy was the unit of analysis (p = 0.036). Conclusion: Functional MRI data may not strengthen the ability of T2WI to detect locally recurrent prostate cancer in patients who have undergone radical prostatectomy. By contrast, diffusion-weight MRI and $^1H$-MRS data may improve the sensitivity of T2WI for patients who have undergone radiotherapy.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.353-358
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• 2018

In this study, it is describe to an optimization analysis process for the weight reduction of the voltage converter in the electric vehicle charging systems. The optimization design is a technique that finds the optimal material distribution under a given material quantity constraint by combining the design sensitivity with the material properties and the mathematical optimization. Among the topology optimization, a lightweight design is performed by a solid isotropic material with penalization with simple formula and well-convergence. The lightweight design consists of three steps. As a first step, a finite element model for the basic design of the on-board voltage converter was constructed and static analysis was performed on the load. In the second step, the optimum shape is obtained for the lightweight by performing the topology optimization using the solid isotropic material with penalization applying the stiffness coefficient of the isotropic material to the static analysis result. As a final step, impact analysis was performed by applying a half-sinusoidal pulse shape impact load which satisfies the impact test standard of the vehicle-mounted part with respect to the optimum shape. In the topology optimization, the design domain was defined as the mounting bracket area, and the design technology was finally achieved by optimizing the mounting bracket to achieve a weight reduction of 20% over the basic design.