• ETRI Journal
• /
• v.44 no.4
• /
• pp.672-685
• /
• 2022

This article proposes a subject-independent application of brain-computer interfacing (BCI). A 32-channel Electroencephalography (EEG) device is used to measure imagined speech (SI) of four words (sos, stop, medicine, washroom) and one phrase (come-here) across 13 subjects. A deep long short-term memory (LSTM) network has been adopted to recognize the above signals in seven EEG frequency bands individually in nine major regions of the brain. The results show a maximum accuracy of 73.56% and a network prediction time (NPT) of 0.14 s which are superior to other state-of-the-art techniques in the literature. Our analysis reveals that the alpha band can recognize SI better than other EEG frequencies. To reinforce our findings, the above work has been compared by models based on the gated recurrent unit (GRU), convolutional neural network (CNN), and six conventional classifiers. The results show that the LSTM model has 46.86% more average accuracy in the alpha band and 74.54% less average NPT than CNN. The maximum accuracy of GRU was 8.34% less than the LSTM network. Deep networks performed better than traditional classifiers.

• Wind and Structures
• /
• v.38 no.3
• /
• pp.161-170
• /
• 2024

In recent years, there have been an increasing number of experimental studies showing the need to include robustness criteria in the design process to develop complex active control designs for practical implementation. The paper investigates the crosswind aerodynamic parameters after the blocking phase of a two-dimensional square cross-section structure by measuring the response in wind tunnel tests under light wind flow conditions. To improve the accuracy of the results, the interpolation of the experimental curves in the time domain and the analytical responses were numerically optimized to finalize the results. Due to this combined effect, the three aerodynamic parameters decrease with increasing wind speed and asymptotically affect the upper branch constants. This means that the aerodynamic parameters along the density distribution are minimal. Taylor series are utilized to describe the fuzzy nonlinear plant and derive the stability analysis using polynomial function for analyzing the aerodynamic parameters and numerical simulations. Due to it will yield intricate terms to ensure stability criterion, therefore we aim to avoid kinds issues by proposing a polynomial homogeneous framework and utilizing Euler's functions for homogeneous systems. Finally, we solve the problem of stabilization under the consideration by SOS (sum of squares) and assign its fuzzy controller based on the feasibility of demonstration of a nonlinear system as an example.

• Journal of the East Asian Society of Dietary Life
• /
• v.21 no.5
• /
• pp.625-636
• /
• 2011

The purpose of this study was to evaluate the relationship between bone health and sodium intake in female university students using a dish frequency questionnaire (DFQ 125), anthropometric checkups, food records for 3 days, and ultrasound measurement of calcaneus bone mineral density. Subjects were divided into two groups: normal (n=196) and osteopenia (n=52). There were no significant differences in age or height between the two groups. The average weight, body mass index, and body fat in the normal group were significantly higher than in the osteopenia group. The sodium intake of DFQ was positively correlated with the sodium intake of 3 days of dietary records (p=0.0003). There were no significant differences in the sodium intake between the two groups from DFQ. The dishes were ranked by sodium intake: kimchies were 17.68%, noodles and mandu were 16.36%, stews were 13.69%, main dishes such as meat, egg, and beans were 11.47%, and fish and shellfish were 11.07%. The frequency of eating noodles and mandu (p=0.0116), stews (p=0.0008), kimchies (p=0.0482), fish and shellfish (p=0.0362), vegetables (p=0.0064) and seasoning (p=0.0347) were negatively associated with bone mineral density. Bone health was not significantly different with increasing quartiles of sodium intake. As excessive sodium intakes may indirectly affect bone mineral density, these results suggest that to prevent osteoporosis, university students needed to be more educated about diets containing less sodium through nutrition education programs.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.1
• /
• pp.31-39
• /
• 2008

Sensor Node OS should support unified API and efficient sensor device management system to overcome the diversity of sensors and actuators. However, conventional OSs like Tiny-OS and Nano-Q+ do not. In this paper, we propose a sensor device driver management system that present application programmers with unified API and easy deployment of sensors. When a sensor is deployed in our device management system, the device driver is downloaded. This scheme differs from traditional OS like SOS in that only sensor device driver is downloaded, not the whole application image. We designed and implemented the system into Nano-Q+. We described the comparison with other OSs and showed that our system obtains the considerable speedup of downloading.

• International Commerce and Information Review
• /
• v.15 no.3
• /
• pp.111-133
• /
• 2013

The purpose of this study is to evaluate the effect that the utilization motivation of SNS (Social Network Service) marketing affects on the export performance of medium small sized exporting enterprises (MSEE) directly and indirectly. This study is to investigate the effects of the export marketing environment of MSEE onto the motivation of SNS application and then it proposes a model which evaluates the performance of SNS marketing. In this study, for data collection and analysis questionnaire, survey was conducted for MSEE participated in trade exhibitions sponsored by COEX and used TradeSOS consulting services of Korea International Trade Association. The results showed that MSEE utilized SNS for cost reduction.

• Korean Journal of Community Nutrition
• /
• v.10 no.1
• /
• pp.91-100
• /
• 2005

This study was conducted to investigate the effects of smoking on nutrition intake, bone mineral density and blood mineral status. The subjects were composed of two groups: 100 smokers and 100 non-smokers was used along with a questionnaire. Anthropometric measurements, dietary intakes using 24-hours recall method were compared. At twenty subjects from each group were selected, bone mineral density were measured by quantitative ultrasound and plasma mineral levels were analyzed by ICP spectrometer. The average ages of smokers and non-smokers were 23.9 and 22.8 years old, respectively. The height, weight and BMI of the smokers were no significant difference. The average numbers of smoked cigarettes were 11.8/d and the average packyear was 3.1 in the smokers. About $97\%$ of the smokers drank alcoholic beverages, while $85\%$ of the non-smokers did. The smokers tended to eat less meals and dinner meal, but drink coffee more often compared to the non-smokers. The mean daily energy intake and CPF energy intake ratio were 2184. 9 kcal and 57.2 : 13.7 : 26.4 in the smokers and 2262.6 kcal and 55.8 : 13.1 : 28.6 in the non-smokers. The smokers consumed significantly lower intake of $\beta$-carotene. There were no significant differences in bone mineral density of BUA, SOS and QUI. There were no significant differences in plasma levels of Ca, Mg, Fe and Zn. However, plasma Cu level of the smokers was significantly higher than that of the non-smokers. In conclusion, the smokers of this study showed a more undesirable dietary intake in the light of their low ,B -carotene and high alcoholic beverages, and coffee. The plasma Cu level of the smokers was higher than that of the non-smokers, showing that Cu is involved in smoking. Therefore, it could be suggested that more systematic research be conducted with respect to Cu and smoking and that increased nutrition education and guidelines for smokers are required.

• Architectural research
• /
• v.17 no.1
• /
• pp.13-20
• /
• 2015

The physical environment can dramatically affect students' feeling and their behavior, educational attainment, and the way in which we do school activities. Unlimited access to campus areas without appropriate securities have reported an increase of crime in school area and safety issues has encouraged school facility planners to install securities devices at every corner of buildings. However, it is still questionable whether this approach is enough to protect students and staffs from the victimization of crime, including thefts, burglaries and sexual offences. There has been continued doubt about the safety of educational facilities where individual college students are studying and enjoying extra-curricular activities. Therefore, the purpose of this study is intended to investigate the effects of perception of safety by students on the level of academic performance at public outdoor environment of university campus. An extensive literature noted that the central element of modern school design principle mainly holds the theory of crime prevention through environmental design (CPTED) and the concept of defensible space. The second generation of CPTED also focused on social soft issues as well as situational factors, which extends beyond mere physical design to include social factors. The correlation analysis found that the effect of sense of safety does appear to be statistically significant on the facilitation of academic achievement. However, the analysis of Chi-square concluded that the perception of safety was not related to demographic and socio-economic profiles of the group except for gender. Further, stepwise multiple regression analysis revealed that the most prime predictor for academic achievement were 'safe public outdoor space/paths' at university campus environment, implying careful design of public open space and sidewalks based on the guideline of CPTED. The study also demonstrated that as the level of positive perception of safety rose, the overall academic achievement also responded to the specified rate (${\beta}=.99$). Finally, the findings reinforce an evidence that high-quality school environments are a positive factor in student academic performance.

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.2
• /
• pp.75-85
• /
• 2007

There are many embedded systems which store and play multimedia streams on optical media such as recordable cd and dvd. Some of those are PVRs, DVRs, and camcorders. In this paper we describe the design and implementation of a new, well structured, fully documented, operating system independent and open source optical media API which can be used in various applications and embedded systems. We also design an ISO-9660 compliant optical media layout, an API set and the scenario for real-time recording. To prove the usability, we develop a text application to replace well-known CD-burning software, cdrecord, and a graphic burning application. All the implementations are firstly done on Linux PC environment, and then ported to a commercial embedded system which uses pSOS as an operating system.

• Parasites, Hosts and Diseases
• /
• v.46 no.1
• /
• pp.45-48
• /
• 2008

To evaluate the usefulness of the Korean Isolate-1 (KI-1) antigen for serodiagnosis of toxoplasmosis, antigen profiles of KI-1 tachyzoites were analyzed in comparison with RH tachyzoites by SOS-PAGE and immunoblotting. ELISA was performed on latex agglutination (LA)-positive and negative serum samples using KI-1 and RH antigens. Immunoblotting of the KI-1 antigen showed multiple antigen bands with molecular sizes of 22-105 kDa. Among them, 1 and 6 common bands were noted against a KI-1-infected and a RH-infected human serum, respectively, which represented differences in antigenic profiles between KI-1 and RH tachyzoites. However, all 9 LA-positive human sera were found positive by ELISA, and all 12 LA-negative sera were negative by ELISA; the correlation between the ELISA titers and LA titers was high (r = 0.749). Our results suggest that tachyzoites of KI-1 may be useful for serodiagnosis of human toxoplasmosis.

• Journal of Life Science
• /
• v.14 no.5
• /
• pp.840-846
• /
• 2004

A study for expression of Korean Mistletoe (KM) lectin gene (A,B) in Saccharomyces cerevisiae was done using transforming system of yeast. In order to overexpress the genes efficiently in yeast, two lectin genes (A,B) were re-cloned and modified including Kozak translation initiation sequence using PCR amplification. The constructed plasmids containing modified lectin A and B genes were transformed to S. cerevisea INVSc (MAT G, his3 $\Delta$1, leu2, trpl-289, ura3-52). The transformed cells were identified by DNA sequencing with ABI3700 system and induced with 2% of galactose for recombinant KM lectin (rKM lectin) protein. The rKM lectin A and B proteins were determinated about 29kDa size of protein by SOS-P AGE and western blotting analysis. The expressed recombinant lectin was determinated 1.24∼1.75 $\mu\textrm{g}$ per 1 mg of cytosolic soluble protein by sandwich ELISA method. Moreover the lectin genes were expressed as maximum level at 36 h after galactose induction and lectin A gene was were repressed after 48 h.