• Science of Emotion and Sensibility
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• v.6 no.3
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• pp.13-20
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• 2003

In an experimental study, we assessed human sensibility in terms of psychophysiological response according to change of speeds (40, 70, 100km/h) in a driving simulator and application of motion fitters (washout filter, non-washout later) in a roller coaster simulator. For the driving and roller coaster simulators, a group of 12 healthy men in their twenties and a group of 8 healthy men in their twenties, respectively, participated. Participants each completed a simulator sickness questionnaire (SSQ), a subjective assessment of sensations of pleasantness, tension, and arousal, and perception of speed. Physiological signals were measured by 1/f fluctuation of EEG (electroencephalogram), ECG (electrocardiogram), and GSR (galvanic skin response). These were measured pre-to-post under the experimental conditions for each simulator. Subjective pleasantness, tension, arousal, and perception of speed and physiological responses indicating a feeling of pleasantness by 1/f fluctuation were higher for the roller coaster simulator than those measured for low speed driving in the driving simulator. The mean frequency of alpha band (8-l3㎐) in EEG increased with exposure to the driving simulator relative to that for the roller coaster simulator. Heart rate variability and GSR were significantly changed between pre- and post- under each condition in the driving and roller coaster simulators. The data suggest that subjective sensibility was elevated according to gain of speed and variety of simulator motion, and physiological responses were activated with increased speed.

• The Journal of Society for e-Business Studies
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• v.18 no.2
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• pp.279-299
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• 2013

The problem of choosing the right product that will best fit a consumer's taste and preferences extends to the field of electronic commerce. However, e-commerce has been able to create a technological proxy for the social filtering process, known as online recommender systems (RSs). RSs aid users in filtering products and decisions on matters relating to personal taste. RSs have the potential to support and improve the quality of the decisions consumers make when searching for and selecting products and services online. However, most previous research on RSs has focused on the accuracy of the algorithms, with little emphasis on user interface and perspectives. This study identified transparency and feedback as possible ways to effectively evaluate RSs from the user's perspective. Thus, this research focused on examining and identifying the roles of transparency and feedback in recommender systems and how they affect users' attitudes toward the system. Results of the study showed that both transparency and feedback positively and significantly affected perceived trust, perceived value of the process, and perceived enjoyment. Furthermore, we found that perceived trust, perceived value of the process, and perceived enjoyment positively and directly affected users' intentions to use/reuse a recommender system.

• Journal of Radiation Protection and Research
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• v.29 no.3
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• pp.179-186
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• 2004

A single-dosimeter worn on the anterior surface of body of a worker was found to provide significant underestimation of dose to the worker when radiation comes from behind of the human body. Recently, several researchers suggested that this kind of underestimation can be corrected to a certain extent by using an extra dosimeter on the back. But this multiple dosimetry also has the disadvantages like overestimation lowering work efficiency or cost burden. In this study, a single dosimeter introducing asymmetric filters enabled to identify PA exposure was designed by monte-carlo simulation and experiments and its dose evaluation algorithm for AP-PA mixed radiation field was established. This algorithm was applicable to penetrating radiation which had the effective energy more than 100 keV. Besides, the dosimeter and algorithm in this study were possible to be applied to near PA exposure.

• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.165-177
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• 2008

Small baseline subset (SBAS) algorithm has been recently developed using an appropriate combination of differential interferograms, which are characterized by a small baseline in order to minimize the spatial decorrelation. This algorithm uses the singular value decomposition (SVD) to measure the time-series surface deformation from the differential interferograms which are not temporally connected. And it mitigates the atmospheric effect in the time-series surface deformation by using spatially low-pass and temporally high-pass filter. Nevertheless, it is not easy to correct the phase unwrapping error of each interferogram and to mitigate the time-varying noise component of the surface deformation from this algorithm due to the assumption of the linear surface deformation in the beginning of the observation. In this paper, we present an improved SBAS technique to complement these problems. Our improved SBAS algorithm uses an iterative approach to minimize the phase unwrapping error of each differential interferogram. This algorithm also uses finite difference method to suppress the time-varying noise component of the surface deformation. We tested our improved SBAS algorithm and evaluated its performance using 26 images of ERS-1/2 data and 21 images of RADARSAT-1 fine beam (F5) data at each different locations. Maximum deformation amount of 40cm in the radar line of sight (LOS) was estimated from ERS-l/2 datasets during about 13 years, whereas 3 cm deformation was estimated from RADARSAT-1 ones during about two years.

• Journal of Chest Surgery
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• v.38 no.12 s.257
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• pp.821-827
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• 2005

Background: Hemodilution after priming of the cardiopulmonary bypass is known to increase the possibility of bleeding and homologous transfusion in adult cardiac surgery. We investigated the effects of retrograde autologous priming (RAP) to see whether it would decrease postoperative bleeding and homologous transfusion. Material and Method: We retrospectively reviewed 34 patients wpho underwent RAP and 46 patients who did not. Retrograde autologous priming consisted of arterial lire drainage, venous reservoir and oxygenator drainage and venous line drainage. We compared the amount of priming solution and RAP volume, perioperative hematocrit, postoperative bleeding and transfusion requirements in the two groups. Resuit: Mean withdrawal volume in RAP group was 613.5$\pm$160.6 mL and initial priming volume was 1381.9$\pm$37.2 mL. Hemoatocrits ($\%$) in RAP and control groups were 25.0$\pm$3.7 vs 20.9$\pm$3.6 (5 minutes after CPB), 25.9$\pm$3.7 vs 22.5$\pm$3.6 (30 minutes after CPB), 25.9$\pm$3.4 vs 23.8$\pm$2.8 (60 minutes after CPB), 31.9$\pm$3.9 vs 31.5$\pm$4.5 (postoperative 1 hour), 32.4$\pm$4.4 vs 32.1$\pm$4.5 (postoperative 6 hours), 33.4$\pm$5.0 vs 31.7$\pm$5.1 (postoperative 1 day)[repeated measures ANOVA, p < 0.05]. Chest tube drainages (mL) in the two groups were 357.2$\pm$177.1 vs 411.7$\pm$279.5 (postoperative 6 hours), 599.4$\pm$145.6 vs 678.8$\pm$256.4 (postoperative 24 hours)[t-test, p < 0.05]. Homologous transfusion was performed in 7 out of 34 patients in RAP group (20.6$\%$), and 16 out of 46 (34.8$\%$) in control group (p < 0.05). Conclusion: This study suggests that the effects of reducing the priming volume during cardiopulmonary bypass may result in lesser bleeding and homologous transfusion. Retrograde autologous priming would be used to reduce postoperative bleeding and chance of transfusion after adult cardiac surgery.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.56-66
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• 1999

Growth of Dendranthema grandiflorum R. ‘Bongwhang’plantlets, as affected by three levels of photosynthetic photon flux (PPF), 70, 150 and 220 $\mu$mol. $m^{-2}$ . $s^{-1}$ , three levels of C $O_{2}$ concentration, 400-500 (ambient), 1000 and 2000 $\mu$mol.mo $l^{-1}$ , and two levels of number of air exchanges per hour (NAEH), 0.1 $h^{-1}$ and 2.8 $h^{-l}$, was studied. Explants were obtained from photomixotrophically-micropropagated plantlets. Four explants were planted in each 3.7$\times$10$^{-4}$ $m^{3}$ polycarbonate box containing MS medium supplemented with 1.25 meq. $L^{-1}$ $H_{2}$P $O_{4}$$^{[-10]}$ and no added sugar. Explants were cultured under cool-white fluorescent lamps (16 h. $d^{-1}$ ), at 25$\pm$1$^{\circ}C$ temperature, and 70-80% relative humidity. In treatments of 2.8 $h^{-1}$ NAEH, a 10 mm round hole made on the vessel cap was sealed with a microporous filter For higher C $O_{2}$ concentrations in the culture room, C $O_{2}$ gas was provided from a tank of liquefied C $O_{2}$. Fresh and dry weights, height, length of the longest roots, number of leaves, and leaf area significantly increased with increasing PPF and especially, with increasing C $O_{2}$ concentration. Growth was enhanced with increased number of air exchanges per hour (2.8 $h^{-1}$ ). Overall, treatment of 220$\mu$mol. $m^{-2}$ . $s^{-1}$ PPF combined with 2000$\mu$mol.mo $l^{-1}$ C $O_{2}$ and 2.8 $h^{-1}$ NAEH gave the most vigorous growth of Dendranthema grandiflorum R. ‘Bongwhang’ plantlets in vitro.o.

• Economic and Environmental Geology
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• v.34 no.4
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• pp.375-383
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• 2001

We extracted sea surface heights(SSH) from the TopexJPoseidon(T/P) radar altimeter data to compare with fhe SSH estimated from in-situ lide gauges(T/G) at Ulleungdo, Pohang, and SockcholMucko sites. Selection criteria such as wet/dry troposphere, ionosphere, and ocean tide were used to estimate accurate SSH. For time series analysis, the one-hour interval tide gauge SSHs were resampled al lO-day interval of the satellite SSHs. The ocean tide model applied in the altimeter data processing showed periodic aliasings of 175.5 day, 87.8 day, 62J day, 58.5 day, 49.5 day and 46.0 day, and, hence, the ZOO-day filtering was applied to reduce these spectral noises. Wavenumber correlation analysis was also applied to extract common components between the two SSHs, resulting in enhancing the correlation coefficient(CC) dramatically. The original CCs between the satenite and tide gauge SSHs are 0.46. 0.26, and 0.]5, respectively. Ulleungdo shows the largest cc bec;luase the site is far from the coast resulting in the minimun error in the satellite observations. The CCs were then increased to 0.59, 030, and 0.30, respectively, after 200.day filtering, and to 0.69, 0.63. and 0.59 after removing inversely correlative components using wavenumber correlation analysis. The CCs were greatly increased by 87, 227, and 460% when the wavenumber correlation analysis was followed by 2oo-day filtering, resulting in the final CCs of 0.86, 0.85, 0.84, respectively. It was found that the best SSHs were estimated when the two methods were applied to the original data. The low-pass filtered TIP SSHs were found to be well correlated with the TIG SSHs from tide gauges, and the best correlation results were found when we applied both low-pass filtering and spectral correlation analysis to the original SSHs.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.51-58
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• 2005

The objective of this study was to evaluate the effect of cigarette filter on in vitro cytotoxicity of cigarette mainstream smoke from the cigarette. In this work, we used 3 types of cigarettes included non-filtered 2R4F cigarette, cellulose acetate-filtered 2R4F cigarette, and carbon dual-filtered 2R4F cigarette which was made from original 2R4F by replacing with an acetate filter containing carbon. The cytotoxicity of both the cigarette smoke condensate (CSC), which was collected in Cambridge filter pad, and the gas/vapor phase (GVP), which was bubbled through in phosphate-buffered saline in a gas-washing bottle, was determined using a neutral red uptake assay with CHO-K1 cells. With regard to cytotoxicity when calculated on an equal puff basis, the cytotoxicity of CSC from the filtered cigarettes was lower than that of the non filtered cigarette. Also, $EC_{50}$ vlaue of GVP from carbon filter cigarette was 40.9 puff/L, indicating the cytotoxicity to be $20\%$ lower than that of the CA filter cigarette. The cytotoxicity of the GVP was correlated to the several vapor phase components (formaldehyde, acetaldehyde, acetone, acrolein, crotonaldehyde and MEK). In conclusion, carbon filter, which significantly reduced the amount of carbonyl compounds in mainstream cigarette smoke, results in significant reductions in the cytotoxicity potential of the smoke.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1143-1150
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• 2001

In this paper, we designed a downconverter for K-band satellite multipoint distribution service(SMDS). The designed downconverter consists of a low noise amplifiers, bandpass filter, stable local oscillator, drain mixer and If Amplifiers. Low noise amplifiers show 28㏈ gain and 1.5㏈ noise figure in the frequency range of 19.2㎓~20.2㎓, and a band pass filter has a -l㏈ insertion loss, and 18.25㎓ Stable local oscillator which is dielectric resonant oscillation, We obtained that the output power of the 18.25㎓ oscillation frequency is 0.5㏈m and the phase noise is the -84.67㏈c at 10KHz offset frequency. With the input RF signal the 19.2㎓~20.2㎓, conversion gain of the drain mixer shows 5㏈ at the Intermediate frequency range of 950MHz~1950MHz. We have proved that the designed downconverter satisfied the specification of a K-band satellite multipoint distribution service and it can be applied to the satellite internet receiver.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1785-1791
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• 2010

This paper describes a separable microfluidic device fabricated with PDMS (polydimethylsiloxane) and glass. The device is used for sample preparation involving cell lysis and the DNA purification process. The cell lysis was performed for 2 min at $80^{\circ}C$ in a serpentine-type microreactor ($20 {\mu}l$) using a Au microheater that was integrated with a thermal microsensor on a glass substrate. The DNA that was mixed with other residual products during the cell lysis process was then filtered through a new filtration system composed of microbeads (diameter: $50 {\mu}m$) and PDMS pillars. Since the entire process (sample loading, cell lysis reaction, DNA purification, and sample extraction) was performed within 5 min in a microchip, we could reduce the sample preparation time in comparison with that for the conventional methods used in biochemistry laboratories. Finally, we verified the performance of the sample preparation chip by conducting PCR (polymerase chain reaction) analysis of the chip product.