• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.989-996
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• 2009

In this study, the effects of biofilter media type (three different activated carbons and anthracite), empty bed contact time (EBCT) and temperature on the removal of four aldehyde species (formaldehyde, acetaldehyde, glyoxal and methylglyoxal) in BAC filters were investigated. Experiments were conducted at three water temperature (5, 15 and $25^{\circ}C$) and four EBCTs (5, 10, 15, and 20 min). The experimental results indicated that the coal based BAC retained more bacterial biomass on the surface of the activated carbon than the other BACs, and increasing EBCT or increasing water temperature also increased the four aldehyde species removal in BAC filters. To achieve above 80% of removal efficiency for four aldehyde species in a BAC filter, above 15 min EBCT at $5^{\circ}C$ and 10 min EBCT at above $15^{\circ}C$ were required. The kinetic analysis indicated a first-order reaction rate for the biodegradation of four aldehyde species at various water temperatures. Data obtained from the BAC filters at various temperatures were also used to evaluate pseudo first-order rate constants for four aldehyde species. The half-lives evaluated for formaldehyde, acetaldehyde, glyoxal and methylglyoxal in the coal-based BAC ranging from 0.89 to 3.19 min, from 0.75 to 3.35 min, from 2.16 to 4.72 min and from 1.49 to 3.86 min, respectively, could be used to assist water utilities in designing and operating BAC filters.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.418-425
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• 2015

Anaerobic Filters (AF) packed with porous ceramic floating media were operated at different operational conditions to identify the feasibility of the renewable bioenergy, methane production from swine wastewater and to verify the suitability of effluent from anaerobic filters for the subsequent biological nitrogen and phosphorus removal. Stepwise increase in organic loading rates (OLRs) or decrease in hydraulic retention times (HRTs) with influent TCOD concentration of 14,000 mg/L were utilized at mesophilic temperature. The maximum methane productivity of 1.74 volume of $CH_4$ per volume of reactor per day (v/v-d) was achieved at an hydraulic retention time (HRT) of 0.5 day (OLR 28 g TVS/L-d). Based on the biogas production, the highest total volatile solids (TVS) removal efficiency of 63% was obtained at an HRT of 3 days (OLR 4.67 g TVS/L-d), however based on the result from the effluent total chemical oxygen demand (TCOD) analysis, the highest TCOD removal efficiency of 75% was achieved. The effluent alkalinity concentration over the range of 2,050~2,980 mg/L as $CaCO_3$ at all operational conditions, could compensate the alkalinity destruction caused by nitrification. The effluent from the anaerobic filter operated under the HRT of 2 days showed the COD/TKN ratio of 15~35 and COD/TP ratio of 38~56. Therefore effluent C/N/P ratio is able to satisfy the optimum COD/TKN ratio of greater than 8.0 and COD/TP ratio of 33 for the subsequent biological nutrient removal.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.145-154
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• 2017

It is aimed to examine the effect of literary therapy program on the improvement of friendship among elementary school students using various media and activities of literature. After the literature therapy program was conducted for elementary students, post-test was conducted. The results of the study are as follows. First, there was no significant difference between the experimental group and the comparative group in the post-test immediately after the end of the program, but in the follow-up test performed 5 weeks after the counseling, the average of the peer relations of the experimental group was significantly higher than that of the comparative group. Second, in the post-test, there was no significant difference between the experimental group and the comparative group in the "intimacy" sub-area of the peer relationship, but in the follow- up test, the "intimacy" sub-region average of the experimental group was significantly higher than the comparative group. Third, the level of 'interest' among the peer relationship sub-domains of the experimental group showed a significant difference in the follow-up test. As a result, literature therapy had no immediate effect on the improvement of friendship among adolescents, but it was effective after a long time.

• Korean journal of communication and information
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• v.45
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• pp.425-462
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• 2009

The present study delves into how rape reports are framed in popular Korean newspapers over time. Specifically, the primary purpose of this study was to examine how rape myths and ambivalent sexism and were presented in three Korean newspapers. In order to assess longitudinal trends of rape reports, the sample for the content analysis was drawn from 1990 to 2007. Four newspapers, Chosun-Ilbo, Dongah-Ilbo, Jungang-Ilbo and Hankyoreh, which have been the most popular in terms of circulation and ad revenues, were selected for this longitudinal content analysis. Using random stratified sampling and screening process, A total of 2160 articles were content analyzed for the main study. The results revealed that rape reports appearing in Korean newspapers were overwhelmingly dominated by episodic frame rather than thematic frame. Particularly, It was found that Korean rape reports generally have attributed the cause of rape crimes to the victims. Implications for results were discussed in terms of rape myth and ambivalent sexism theories.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.470-474
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• 2008

The image as a media has changed consistently since it was first introduced. According to these changes, the image has been reproduced in different fields and contexts. Thus, the paradigm on the production and the consumption of the image has been changed and recycled rapidly. The relation between the production and the consumption of the image also has changed accordingly, allowing quite ambiguous distinction between the producer and the consumer. The transformation through the transfer of the image among different fields opens up a new potential that these reproduced images could be used as an aesthetically expressive tool, rather than merely leaving images to remain royal to its original function as a sign. The thesis is to explore the potential that the topographical lines have beyond its function as a sign age. During the reproduction of the image, the process actively invites the spectator or the consumer to participate in the formation of the image, which promotes a new relation between the producer and the consumer. Instead, the process encourages the consumers to be active producers as well. As a result, the topographical lines do not merely remain as a sign that demarcates the height of the topography, and new images are constantly reproduced from the active participants. This project questions the fixed idea on the sign as a communicative tool, and suggests a new potential for the sign, especially, the topographical lines.

• KSBB Journal
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• v.14 no.6
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• pp.718-723
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• 1999

In order to treat of alkaline dye-processing wastewater, alkalophilic strains biodegrading azo dye, Acid red 1, is isolated from natural system, and optimal culture conditions are examined using response surface analysis, statistical analysis system program. 15 different species which grow in alkaline culture media are isolated from the effluent and river soil discharged from wastewater treatment plant in dye industrial complex. One strain which has the best decolorization efficiency is chosen, and named as AR-1. The result of the examination of carbon, nitrogen and phosphorus sources which have influence on growth and decolorization reveals that optimum carbon, nitrogen and phosphorus sources are 1.0% fructose, 1.0% polypeptone, 1.0% yeast extract and 0.5% $K_2HPO_4$, respectively. In order to optimize of biodegradation conditions of dye by response surface analysis, the characteristics of decolorization and cell growth according to culture temperature and time are monitered. The result shows that the one is optimum 34.77$^{\circ}C$ for 12.97 hours; the other at 34.73$^{\circ}C$ for 12.96 hours. While, optimal conditions of culture that satisfy both cell growth and decolorization are the temperatures from 32.86$^{\circ}C$ to 36.36$^{\circ}C$ and the period of 10.96 to 15.75 hours, respectively.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.5
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• pp.606-616
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• 2006

Purpose: This experiment examined the effect of different surface treatment on the osseointegration and stability of implants. Material and methods: In this study, 40 each of machined, SLA and RBM implants, which are the most commonly used implants, were implanted into the tibia of 20 normal rabbits using $OsseoCare^{TM}$. The rabbits were sacrificed after 1 week, 4 weeks, 8 weeks and 12 weeks for implant stability analysis, removal torque analysis, histologic and histomorphometric analysis. Result : ISQ showed significant difference between Machined and RBM at first week and at 4 weeks. There was significant difference between Machined and both SLA and RBM(p<0.05) but after 8 weeks there were no significant difference between each group. In the removal torque, RBM showd significantly higher values than SLA and Machined surface at 1st week. At 4th and 12th week, there was significant difference between Machined and SLA, RBM(p<0.05). In the bone to implant contact variable, there was no significant difference between each surface treatment method. In the Machined surface group, there was no significant difference between each time interval. but in SLA group, there were significant differences between the 1st week and 12th week and in RBM group, there were significant differences between the 1st week and 8th, 12th week and between 4th and 12th week(p<0.05). The bone area showed significantly higher values in SLA and RBM compared to Machined surface 1st and 8th week and significantly higher values in SLA than Machined surface at the 4th week(p<0.05). Conclusion: The roughened surface of implants showed positive effect in the early stages of implantation and assisted in bone formation After the bone formation stage, there was no statistical difference between Machined and roughened surface groups. In dental implantation, where initial stability is critical to the success of implants, the use of roughened surface implants should assist in reducing the healing period after implantation.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.1
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• pp.45-53
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• 2009

Objectives: To determinate the optimal culture condition to maintain lifespan in human sperm, we evaluated the effect of different temperature on sperm motility and viability up to 5 days in normal specimens. Methods: Ejaculated semen samples with normal semen parameters were gently washed in HEPES buffered Tyrod's-Albumin-Lactate-Pyruvate (HTALP) media. Each 5 ml of HTALP + 0.3% albumin with $1{\times}10^6$ sperm/ml was incubated for 5 days in $37^{\circ}C$, $22^{\circ}C$, and $4^{\circ}C$. The sperm motility and kinematics were analyzed using computer assisted sperm analysis (CASA), membrane integrity was assessed by hypoosmotic swelling test (HOST), and capacitation status was evaluated by chlorotetracycline (CTC) fluorescence pattern. Each parameter was measured on day 1, 3, and 5, respectively. Results: The motility, viability and live/uncapacitated pattern were demonstrated significantly in temperature- and time-dependent difference (p<0.05). While the sperm cultured for 1 day in each temperature was not significantly different, the sperm cell kept in $22^{\circ}C$ after 3 days were preserved sperm motility, viability, membrane integrity, and F pattern better than in other culture temperatures. Conclusions: HTALP can be used a basic medium for culture and longevity preservation, and sperm cell kept at $22^{\circ}C$ is beneficial for assisted reproductive techniques.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.6
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• pp.9-16
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• 2000

In order to achieve stiction-free polysilicon surfaces, we have suggested a new class of chemical coating precursors and confirmed their excellent characteristics. The strategy is to adopt dialkyldichlorosilanes (DDS, $R2SiCl_2$) instead of monoalkyltrichlorosilanes (MTS, $RSiCl_3$) such as octadecyltrichlorosilane (OTS) or 1H,1H2H,2H-perfluorodecyltrichlorosilane (FDTS). Dichlorodimethylsilane (DDMS, $(CH_3)2SiCl_2$) in this study is commercially available DDS with two short chains. DDMS in aprotic media spontaneously deposits on the hydrophilic polysilicon surface, which is completely changed to hydrophobic one. When polysilicon surface is exposed to DDMS solution at room temperature, anti-stiction property and hydrophobicity are clearly comparable to FDTS. DDMS is even superior to MTS in reliability and easy handling, which provides high yield. Since interactions among precursor molecules are reduced, conglomeration both in homogeneous solution and on surface can be effectively avoided. Even the cantilevers of 3 mm in length can be protected successfully from the stiction and the final quality of the modified surfaces is much less dependent on temperature. And no difference was found between the processes in ambient environment and in dry box. In addition, DDMS has advantages of remarkably reduced process time and low cost.

• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.131-143
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• 2011

Previous alerting service based on LBS was caused severe overload problem of server by using the method to confirm the location of each moving object on server. In this paper, by loading an App on smart moving object, we proposed a novel algorithm named ADAS(Active Disaster Alert Service) for accessing to the server site with oneself location information as needed and implemented the disaster alerting service system with visualization for user. In the proposed method, running App access to the server periodically with the present location coordinate gained from GPS module or network module and the ID of moving object. Then, the server compare the present location coordinate of moving object and the coordinates of disasters registered in DIDB and transmit the n NDIs existed in near distance orderly from the coordinate of present moving object to the client. The App compares the coordinate of present location for moving object and the coordinates of NDI is transmitted from server by real time and executes the service with classifying levels of alert into three steps such as danger, carefulness and safety. And new NDIs are gained by accessing DIDB on Server periodically during running App. Therefore, this will be become a novel method for reducing fundamentally the server overload problem in comparison with previous alerting service that the career of moving object is managed on server.