• Environmental Engineering Research
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• 제24권1호
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• pp.17-23
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• 2019

This study monitored changes in the level of heterotrophic bacteria in the filtrate and investigated the effect of stagnant water on it, using a batch-operated, gravity-driven membrane system for household water treatment. The filtration test was carried out in the presence and absence of stagnant water in the filtrate line. The results showed that stagnant water accelerated the heterotrophic bacteria levels, measured by heterotrophic plate count, even though the heterotrophic plate count of the filtrate finally increased up to $10^5CFU/mL$ regardless of the presence of stagnant water. When the change in heterotrophic plate count of a batch was monitored over filtration time, heterotrophic plate count of the filtrate rapidly decreased within 5 min for each batch filtration. Biofilm formation on the filtrate line was observed in the presence of stagnant water. The biofilm fully covered the filtrate line and contained numerous microorganisms. During storage after filtration, heterotrophic plate count increased exponentially. To improve the filtrate quality of a filtration-based household water treatment system, therefore, the stagnant water in the filtrate line should be minimized, the filtrate produced at the first 5 min is recommended not to be used as potable water, and the storage of filtrate should be avoided.

• 한국게임학회 논문지
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• 제19권1호
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• pp.135-146
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• 2019

2018년부터 국제보건기구의 게임 장애의 국제 질병 코드(ICD-11) 등재 계획이 본격화하면서 세계적으로 학자들 간에 뜨거운 토론이 있었다. 하지만 대한민국은 등재의 부당함에 대한 학문적 근거 제시 없이 회피만 해온 것 같다. 본 논문에서는 게임 중독/장애와 관련한 과거의 학술 연구의 쟁점과 연구 오류 및 왜곡 사례들을 뇌 사진 판독과 게임 중독/이상 진단 도구의 적절성 등을 중심으로 짚어 본다. 본 분석은 게임의 과도한 사용이 게임의 질병 코드 등재의 충분 조건이 아니며 대다수의 건강한 게이머들에게 부당한 낙인을 찍어버릴 위험이 있음을 밝힌다.

• Earthquakes and Structures
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• 제17권2호
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• pp.191-204
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• 2019

Near-field earthquake records including long-period high-amplitude velocity pulses can cause large isolation system displacements leading to buckling or rupture of isolators. In such cases, providing supplemental damping in the isolation system has been proposed as a solution. However, it is known that linear viscous dampers can reduce base displacements in case of near-field earthquakes but at the potential expense of increased superstructure response in case of far-field earthquakes. But can non-linear dampers with different levels of non-linearity offer a superior seismic performance? In order to answer this question, the effectiveness of non-linear viscous dampers in reducing isolator displacements and its effects on the superstructure response are investigated. A comparison with linear viscous dampers via time history analysis is done using a base-isolated benchmark building model under historical near-field and far-field earthquake records for a wide range of different levels of non-linearity and supplemental damping. The results show that the non-linearity level and the amount of supplemental damping play important roles in reducing base displacements effectively. Although use of non-linear supplemental dampers may cause superstructure response amplification in case of far-field earthquakes, this negative effect may be avoided or even reduced by using appropriate combinations of non-linearity level and supplemental damping.

• 웰빙융합연구
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• 제3권4호
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• pp.11-20
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• 2020

Purposes: This is a study on the perception of safety in use according to cosmetic information. Research design, data and methodology: As a result of analyzing 324 women in their twenties living in the metropolitan area, the following conclusions were drawn. Results: As a result of measuring the awareness of cosmetic information, the awareness of 'cosmetic-related knowledge' (M=3.52) and 'cosmetic performance' (M=3.43) was high, indicating that information on cosmetic knowledge was actively shared with each other. It was understood that the method of use and effect were properly recognized and that the cosmetics were selected. 'Correct cosmetic storage method' is significant in the factors of interest in cosmetics (p<.001), and 'the harmful ingredients of cosmetics that should be avoided' are significant in the factors of cosmetic information (p<0.05) and the factors of interest in cosmetics (p<0.01). 'Trouble-causing ingredients' showed a statistically significant difference in safety perception in all factors except cosmetic performance factors. Conclusion: There is a need to construct a system that allows consumers to easily purchase cosmetics that are necessary for their skin by schematically or simplifying the information on the usage period and trouble-causing ingredients after opening the cosmetics to be easily understood.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권7호
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• pp.2345-2358
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• 2022

This paper presents a method to generate stained-glass animation from video inputs. The method initially segments an input video volume into several regions considered as fragments of glass by mean-shift segmentation. However, the segmentation predominantly results in over-segmentation, causing several tiny segments in a highly textured area. In practice, assembling significantly tiny or large glass fragments is avoided to ensure architectural stability in stained glass manufacturing. Therefore, we use low-frequency components in the segmentation to prevent over-segmentation and subdivide segmented regions that are oversized. The subdividing must be coherent between adjacent frames to prevent temporal artefacts, such as flickering and the shower door effect. To temporally subdivide regions coherently, we obtain a panoramic image from the segmented regions in input frames, subdivide it using a weighted Voronoi diagram, and thereafter project the subdivided regions onto the input frames. To render stained glass fragment for each coherent region, we determine the optimal match glass fragment for the region from a dataset consisting of real stained-glass fragment images and transfer its color and texture to the region. Finally, applying lead came at the boundary of the regions in each frame yields temporally coherent stained-glass animation.

• Corrosion Science and Technology
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• 제21권5호
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• pp.390-411
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• 2022

Any design engineer or coating formulator's primary objective is to protect metals. Large investments in terms of money, time, labour, and other resources are necessary for constructing large-scale machinery and structures. In terms of economy, the structure's lifespan should be as long as feasible to create revenue. It is becoming essential to protect metal substrates from corrosion to prolong the lifespan of such huge structures. One of the most exciting, durable, useful, and effective methods to protect metals from corrosion is the application of corrosion-resistant coating. Graphene is a novel material with a wide range of applications because of its extraordinary features. The use of graphene in coating creates an obstacle and complicates the path for corrosive medium to reach the metal. As the path to the metal elongates, the corrosion medium takes longer to reach the metal. Thus, metal corrosion can be avoided. In this paper, the importance of graphene in coating formulation is discussed, including chemical modifications of graphene, the effect of graphene concentration on corrosion inhibition, and the contact angle of coating. This review also highlights the significance of water-based corrosion-resistant coating for preventing environmental damage.

• 한국지진공학회논문집
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• 제27권3호
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• pp.157-162
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• 2023

As a result of active geological investigation of faults in Korea, many Quaternary faults have been identified and some of them were judged to have potential to generate earthquakes. Those faults need to be considered as additional seismic sources in the seismic hazard analysis. When a fault is introduced as a new source, the earthquakes generated by the fault should be removed from the area sources that include any part of the fault, to avoid double counting. In practice, however, double counting cannot completely be avoided as the complete separation of the fault-generated earthquakes from the area sources is impossible due to uncertainties related to the earthquake location, subsurface structures of faults, etc. When a new fault source is introduced, the only constraint is the invariance of earthquake frequency. The maximum earthquake and the Richter-b value should also be subject to change, but there are no competent approaches to estimate the change due to incomplete separation of earthquakes. To gain insight into the effect of a new fault source, an example calculation of the seismic hazard were carried out. The example calculation shows that addition of a new fault source centers seismic hazard around the fault source.

• 대한물리치료과학회지
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• 제18권2호
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• pp.1-8
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• 2011

Background: The purpose of this study was to systematic review the effect of exercise programs for chronic low back pain patients. We needs systematic development of low back pain exercise program to reduce economic cost further doing great service to public health promotion. Methods: We searched to the effects of exercise programs for chronic low back pain patients by Dankook University electronic library databases of DBPIA, KSI KISS, CINAHL, MEDLINE and PEDro combined with a hand search of papers published in relevant journals. Any type of study relevant to the topic published during time period from 1970 to 2007 was included. Results: The literature search identified 30 studies. 1.Performing the flexion exercise increased abdominal muscle activity but acute herniated intervertebral disc should be avoided. 2.The general lumbar extension exercise used lumbar extension machine and the muscle power increases, significant probability the change. 3.The spinal segments exercise for the patients offered significant efficacy and appeared to be a reasonable therapeutic option. 4.Spinal stabilization exercises appear to improve trunk endurance and balance to patients with chronic low back pain. This exercise programs had effective decrease pain and disability. Conclusion: The review suggests that although the exercise programs for chronic low back pain patients, and we expected the efficacy of the exercise programs for chronic low back pain patients used in this study should be further investigated in a long period study and objective outcomes.

• 대한치과보철학회지
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• 제31권1호
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• pp.11-18
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• 1993

Autopolymerising and visible light cured resin are used to reline dentures. But relined surface are easily contaminated by water or saliva in the mouth during clinical procedure. This study was to find out the effect of surface contamination on the transverse strength of the relined denture base. To accomplish this, the specimens of $65\times10\times3mm$ were made with heat-cured(Lucitone 199), visible light-cured(Triad), and autopolymerizing resin(Kooliner). Measurements of transverse strength were taken for each specimen. Specimens made of heat-cured resins, sizing $65\times10\times1.5mm$, were relined with heat-cured, light-cured, and autopolymerizing resin, respectively. Specimens relined with autopolymerizing and light-cured resins were further classified into not-contaminated, water-contaminated and saliva-contaminated groups. Again, measurements of the transverse strength were taken for each group. The results were as follows 1. The transverse strength of heat-cured resin was superior to all the other resins. 2. The transverse strength of each specimen decreased after relining in the following order, heat-cured, visible light-cured, and autopolymerizing resin. 3. Surface contamination produced an decrease in transverse strength, especially in the saliva contaminated group. According to these results, water or saliva contamination should be avoided during intraoral relining procedures.

• The Journal of Korean Physical Therapy
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• 제17권4호
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• pp.457-467
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• 2005

Physiotherapyists frequently use manipulative therapy technique to treat dysfunctionand pain resulting from ankle sprain. Despite the high prevalence of lateral ankle ligament injuries, few studies are available indicating any physical associations with the development of lateral ankle ligament injuries, or information of treatment for lateral ankle ligament injuries. To investigate the effect of passive joint mobilization, the anteroposterior glide on the talus, on increasing weight-bearing dorsiflexion, single support time and VAS. Sixty lateral ankle ligament injuries (grade I and grade II) aged between 17 and 27 years (mean age 21) were recruited. Subjects were randomly assigned to 1 of 2 treatment groups. The control group received a protocol of rest, ice, compression, and elevation (RICE) and massage. The experimental group received the anteroposterior mobilization, using a force that avoided incurring any increase in pain, in addition to the RICE protocol. Subjects in both groups were treated every second day for a maximum of 2 weeks or until the discharge criteria were met, and all subjects were given a home program of continued RICE application. Outcomes were measured after each treatment. The results showed that the experimental group than the control group. Weight-bearing dorsiflexion (F=7.640, P<0.05), single support time (F=85.532, P<0.05) and VAS (F=10.610, P<0.050). Between-groups differences were observed as; experimental group is increased weight-bearing dorsiflexion, single support time and reduced VAS.