• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.67-74
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• 2005

Toxicity tests were performed to evaluate the feasibility of application with prediction models to 10 mixture chemicals (chloroneb, butylbenzylphthalate, pendimethaline, di-n-butylphthalate, di-iso-butylphthalate, diazinon, isofenphos, 2-chlorophenol, 2,4,6-trichlorophenol and p-octylphenol) detected in effluents from wastewater treatment plants (WWTPs). Ten chemicals were selected in the basis of their toxicities to Daphnia magna and the concentrations in effluents measured by GC/MS. Three models including concentration addition (CA), independent action (IA) and effect summation (ES) were employed for the comparison of the predicted and the observed mortality of D. magna exposed to 10 mixture chemicals for 48 hours. With a comparative study it was ineffective to predict the mortality through the CA and the ES prediction model, while the IA prediction model showed a high correlation($r^2\;=\;0.85$). Moreover, the ES model over-estimated the toxicity observed by bioassay experiments about five-fold. Consequently, IA model is a reasonable tool to predict the mixture toxicity of the discharging water from WWTPs.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.5
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• pp.724-729
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• 2008

This paper presents the calculation of the required bandwidth of common frequency bandwidth applying queueing theory for maximizing the efficiency of frequency resource of WPAN(Wireless Personal Area Network) based Digital acoustic and communication devices. It assumed that LBT device(ZigBee) and FH devices (DCP, RFID and Bluetooth) coexist in the common frequency band for WPAN based Digital acoustic and communication devices. Frequency hopping (FH) and listen before talk (LBT) have been used for interference avoidance in the short range device (SRD). The LBT system transmits data after searching for usable frequency bandwidth in the radio wave environment. However, the FH system transmits data without searching for usable frequency bandwidth. The queuing theory is employed to model the FH and LBT system, respectively. As a result, the throughput for each channel was analyzed by processing the usage frequency and the interval of service time for each channel statistically. When common frequency bandwidth is shared with SRD using 250mW, it was known that about 35 channels were required at the condition of throughput 84%, which was determined with the input condition of Gaussian distribution implying safety communication. Therefore, the common frequency bandwidth is estimated with multiplying the number of channel by the bandwidth per channel. These methodology will be useful for the efficient usage of frequency bandwidth.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.2
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• pp.39-50
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• 2018

In this study, the nonlinear interaction of irregular waves with wave breaking and currents around permeable submerged breakwater was investigated with the aid of olaFlow model which is open source CFD software published under the GPL license. The irregular wave performance of olaFlow applied in this study was verified by comparing and evaluating the target frequency spectrum and the generated frequency spectrum for applicability to irregular waves. Based on the applicability of this numerical model to irregular wave fields, in the coexistence fields of irregular waves and currents, the characteristics of wave height, frequency spectrum, breaking waves, averaged velocity and turbulent kinetic energy around porous submerged breakwater with the respect to the beach type and current direction versus wave propagation were carefully investigated. The numerical results revealed that the shape of wave breaking on the crown of the submerged breakwater and the formation of the mean flow velocity around the structure depend greatly on the current directions and the type of the beach. In addition, it was found that the wave height fluctuation due to the current direction with respect to the wave propagation is closely related to the turbulent kinetic energy.

• Journal of Technology Innovation
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• v.27 no.2
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• pp.37-71
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• 2019

How has the passenger car's architecture evolved? In the meantime, the discussions on the car architecture have been mixed, i.e., integral, modular, and the coexistence of two types. Therefore, in this study, we aim to develop two indices can measure the degree of modularization of passenger car and its all modules using global trade data. By applying the indices to the framework of architecture positioning that reflects the hierarchical structure of a product, we examined that the degree of modularization of the passenger car architecture has been enhanced. Meanwhile, the degree of modularization differs across the modules that make up the car. Specifically, we observed the higher degree of modularization in front-end, cockpit and seat modules. Whereas, we found that body module had a relatively low degree of modularization. In particular, we observed that the platform of passenger car has notably modularized due to carmakers' efforts to achieve model diversification and reduction of cost and period in new product development at the same time. Interestingly, we showed that three modules, i.e., engine, chassis (relatively less modularized), and transmission (relatively highly modularized), had a different level of modularization, even if they commonly make up the platform. We contribute to the suggestion for analytical approaches that examine the degree of modularization and its progress longitudinally. In addition, we propose the necessity of decomposition of a system into elements in a study of product architecture, considering the possibly distinctive progress of modularization across the elements.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.979-986
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• 2022

In this study, the virtual exhibition using 3D architectural space was analyzed in terms of the viewer's experience. For this purpose, the analysis items of the virtual architectural space include whether the actual architectural space is reproduced, the introduction of surreal elements, the degree of freedom of movement and circulation, the level of photorealism of spatial expression, the level of reproduction of the exhibits and information provision method, and the interaction with other participants. Six virtual exhibition projects designed by a well-known architect were selected and analyzed. Three directions were found through the analysis. First, even when designing a virtual exhibition space with a high degree of freedom, there is a tendency to present a familiar architectural environment. Second, the current method of creating a virtual architectural space is that the method using a 360-degree rendering image and the method using a game engine coexist with pros and cons. Third, the interaction between participants in the virtual exhibition is implemented only by using a game engine. It is expected that the virtual space production environment using the game engine to be developed will become more advantageous in the future.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.9
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• pp.833-840
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• 2017

This study was attempted to explore in depth the education of cultural diversity in the curriculum and textbooks of middle school according to [1] As a result, the educational goals in the curriculum emphasized[2] the realization of the meaning and value of cultural diversity education reflecting the global citizen education in various time, space background and socio-cultural context. The purpose of the curriculum guidelines is specified, and the following is given: "To properly recognize the diversity of the world culture; To acquire knowledge on cultural diversity; To grasp important functions in the city life, and to have attitudes and qualities required as members of the world, and to develop a pluralistic literacy ability''. In the textbooks, the subjects of the cultural diversity education are mainly based on the curriculum standards, the education area of the 7th grade is the 'human community life', the education area of the 8th grade is the origin and development of the Chinese civilization, Suggesting the scope of the theme 'harmonious coexistence with the world'. In order to analyze cultural diversity education in response to the demands of the times, we analyzed three factors such as diversity, identity, and interrelationship.

• Korean Journal of Psychosomatic Medicine
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• v.25 no.2
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• pp.129-135
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• 2017

Objectives : Little is known about the influence of urinary incontinence and depression on individual's QOL(Quality of life). We aimed to clarify how the interaction between urinary incontinence and depression influences one's QOL. Methods : A total of 1262 patients were enrolled in this study from April, 2011 to July, 2011. We estimated the severity of depressive symptoms and QOL, using SGDS-K, EQ-5D. We also investigated the morbidity of urinary incontinence for each patient in person or by questionnaire. Comparisons of QOL between groups with or without depression, with or without urinary incontinence were established using t-test, ANOVA and Scheffe's post hoc analysis. The interaction between urinary incontinence and depression was analyzed by each domain of QOL, using multiple regression analysis. Results : Patients with depression and urinary incontinence showed significantly higher EQ-5D scores on every domain of QOL than other patients, which means significantly lower QOL. Patients with depression, no urinary incontinence reported lower QOL, especially in the domain of 'usual activity', 'anxiety' and 'visual analogue scale(VAS)', whereas those with urinary incontinence, no depression showed lower QOL in 'motility', 'usual activities' and 'pain' domain. Statistically significant interaction effects of two diseases were observed in the domain of 'VAS', 'self care' and 'anxiety'. Conclusions : Comorbidity of urinary incontinence and depression showed significantly lower QOL of patients, compared with urinary incontinence or depression respectively, which implies additive interaction effects of the two diseases. Optimal diagnosis and treatment of depression should be emphasized for patients with urinary incontinence.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.283-288
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• 1999

The effect of water activity ($a_w,\;0.9{\sim}0.995$) and temperature ($18{\sim}30^{\circ}$C) on in vitro growth and interactions between ochratoxin-producing Aspergillus ochraceus and six other fungi (Alternaria alternata, Aspergillus candidus, A. flavus, A. niger, Eurotium amstelodami, E. rubrum) isolated from maize grain were investigated. A. ochraceus and each six other species were paired and their interactions given a numerical score to obtain an index of dominance ($I_D$) for each species. Generally A. ochraceus was very competitive and dominant against other fungi. It was, however, dominanted by Alternaria alternata and A. niger at high $a_w\;(0.995\;a_w)$, and mutually antagonistic when paired with E. amstelodami and E. rubrum at low $a_w\;(0.9\;a_w)$. The growth rates of each species were also calculated under the same range of environmental conditions. They were markedly influenced by aw and temperature. At high temperature ($30^{\circ}C$), A. ochraceus grew most rapidly under slightly drier conditions ($0.95\;a_w$), while A. alternata, A. flavus and A. niger did at high water availability level ($0.995\;a_w$). At $18^{\circ}C\;and\;25^{\circ}C$, and high $a_w$ level ($0.995\;a_w$), A. alternata grew fastest, while A. candidus, E. amstelodami and E. rubrum grew very slowly. Using Biolog plates the effect of $a_w$ and temperature on utilization patterns of carbon sources in maize was evaluated. The niche overlap index (NOI) relative to A. ochraceus was determined and compared with that of each interacting species. Under high water available condition ($0.995\;a_w$). the NOI of A. ochraceus was often >0.9, indicative of the coexistence with other interacting species. However, against E. amstelodami and E. rubrum at $18^{\circ}C$, the species had NOI <0.8, indicative of occupation of different niches. At low $a_w\;(0.95\;a_w)$, NOI for A. ochraceus was <0.8 when paired with A. alternata and A. niger also suggested the occupation of different niches.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.7 no.1
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• pp.77-91
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• 1996

In order to elucidate the biological etiology and the effects of comorbidity on biological variables in tic disorders, plasma serotonin (5-hydroxlfryptamine, 5-HT) and 5-hydroxy- indoleacetic acid (5-HIAA) we.e measured in 87 tic disorders and 30 control subjects. The 87 tic disorder were composed of 45 Tourette's disorder(TS), 22 chronic motor tic disorders (CMT) and 20 transient tic disorders (TTD). Among these patients,43 patients were pure tic disorder (PT), 28 subject also had attention deficit hyperactivity disorder (T+ADHD) and 16 subjects had obsessive compulsive disorders (T+ OCD) as comorbid disorders. The results are summarized as follows : 1) Plasma 5-HT levels showed significant positive correlations with plasma 5-HIAA levels (Pennon r=0.77, p<0.05). 2) Plasma 5-HT and 5-HIAA levels showed no significant correlation with age in tic disorders. 3) Plasma 5-HIAA and 5-HT levels showed no significant correlations with age in control subjects. 4) There was significant difference in plasma 5-HT levels among TS, CMT, TTD and control groups (ANOVA F=34.48, df=3, 113, p<0.01), and post-hoc test using Scheffe method showed significant differences between control and TS, control and CMT, control and ITD groups. But, post-hoc test showed no significant differences between TS and CMT, TS and TTD, CMT and TTD groups. 5) There was significant difference in plasma 5-HIAA levels among TS, CMT, TTD and control groups (ANOVA F=26.48, df=3, 113, p<0.01), and post-hoc test using Scheffe method showed significant differences between control and TS, control and CMT, control and TTD groups. But, post-hoc test showed no significant differences between TS and CMT, TS and TTD, CMT and TID groups.f) There was significant difference in plasma 5-HT and 5-HIAA levels among PT, T+ADHD, T+OCD and contol groups (ANOVA 5-HT, F=37.59, df=3, 113, p<0.01, 5-HIAA, F=27.37, df=3, 113, p<0.01), and post-hoc test using Scheffe method showed signiscant differences between control and PT, control and T+ADHD and control and T+OCB. But, post-hoc test showed no significant differences between PT and T+ADHD, PT and T+ OCD and T+ADHD and T+ OCD. These results show that decreased 5-HT and 5-HIAA levels may play a role in the genesis of tic disorders, but these findings have no significant correlations with the severity of tic disorders. And the comorbid disorders of tics may have minimal effects on the biochemical abnormalities. Future studies must be focused on the effects of serotonin agonists and antagonists on tic disorders and molecular biological methodology may enhance to elucidate the mechanisms of these abnormal findings.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.9 no.2
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• pp.209-217
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• 1998

Object：The purpose of this study was to investigate that infection with group $A[{\beta}]$ hemolytic streptococcus may associate the mechanisms that cause or exacerbate the tic symptoms in some cases of Tourette's disorder Method：Fourteen cases with abrupt worsening of tics participated in this study：10 males,4 females. The subjects were divided into two groups composing of the group with increasing level of ASO titer and the group with normal level of ASO titer. The subjects were administered Yale Global Tic Severity Scale(YGTSS). Result：The global severity scores and overall TS impairment rating scores of YGTSS in the group with increasing level of ASO titer were more higher than in the group with normal level of ASO titer Conclusion：These results suggest that increasing level of ASO titer, resulting from group $A[{\beta}]$ hemolytic streptococcal infection has affected worsening the tic symptoms in Touette's disorder.