• Journal of Periodontal and Implant Science
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• v.53 no.1
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• pp.69-84
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• 2023

Purpose: The objective of this study was to analyze the microbial profile of individuals with peri-implantitis (PI) compared to those of periodontally healthy (PH) subjects and periodontitis (PT) subjects using Illumina sequencing. Methods: Buccal, supragingival, and subgingival plaque samples were collected from 109 subjects (PH: 30, PT: 49, and PI: 30). The V3-V4 region of 16S rRNA was sequenced and analyzed to profile the plaque microbiota. Results: Microbial community diversity in the PI group was higher than in the other groups, and the 3 groups showed significantly separated clusters in the buccal samples. The PI group showed different patterns of relative abundance from those in the PH and PT groups depending on the sampling site at both genus and phylum levels. In all samples, some bacterial species presented considerably higher relative abundances in the PI group than in the PH and PT groups, including Anaerotignum lactatifermentans, Bacteroides vulgatus, Faecalibacterium prausnitzii, Olsenella uli, Parasutterella excrementihominis, Prevotella buccae, Pseudoramibacter alactolyticus, Treponema parvum, and Slackia exigua. Network analysis identified that several well-known periodontal pathogens and newly recognized bacteria were closely correlated with each other. Conclusions: The composition of the microbiota was considerably different in PI subjects compared to PH and PT subjects, and these results could shed light on the mechanisms involved in the development of PI.

• Composites Research
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• v.22 no.6
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• pp.23-31
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• 2009

This paper investigated acoustic emission (AE) characteristics in association with various fracture processes of glass fiber reinforced plastic skin/ aluminum honeycomb core (GF-AH) hybrid composites under compressive and bending loads. Various failure modes such as skin layer fracture, skin/core interfacial fracture, and local plastic yield buckling and cell wall adhesive fracture occurring in the honeycomb cell wall were classified through the fracture identification in association with the AE frequency and amplitude analysis. The distribution of the event-rate in which it has a high amplitude showed a procedure of cell wall adhesive fracture, skin/core interfacial debonding and fiber breakage, whereas distribution of different peak frequencies indicated the plastic deformation of aluminum cell wall and the friction between honeycomb walls. Consequently, the fracture behaviors of GF-AH hybrid composites could be characterized through a nondestructive evaluation employing the AE technique.

• Composites Research
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• v.19 no.4
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• pp.7-14
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• 2006

Interfacial shear strength between epoxy and carbon fiber has been analyzed utilizing the microbond specimen with an epoxy micro-droplet adhered onto single carbon fiber. The interfacial shear stress distributions along the fiber/matrix interface were calculated by finite element analysis using three kinds of finite element models such as droplet model, circular-crosssection model and pull-out model. Conclusions were obtained as follows. (1) Interfacial shear stress distribution showed that larger stresses were concentrated in the fiber/matrix interface for microbond test than for pull-out test. Thus, debonding at the fiber/matrix interface during microbond test was liable to occur at low load level. (2) Microbond test showed higher interfacial strength which was caused by various effects of micro-droplet geometry and size as well as stress concentration in the region contacting with the micro-vise tip.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.145-157
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• 2009

OSGi enables services to be dynamically discovered through its service registry for fostering interactions among themselves, positioning itself as one of the most prominent SOA technologies. Web Services also provide a mature technical base of open business services being employed over the Internet and allow more value-added applications to be built up from component services. In this paper, we propose a new architecture, built on the concept of dynamic service binding, to support interbred service compositions of OSGi and Web Services. Web Services are imported into OSGi domains, and the compositions are described in WS-BPEL language. The support for crossbred compositions of OSGi services and Web Services opens up a new opportunity of a wider range of applications beyond their respective traditional target domains of home gateways in LAN environments and business applications in global Internet environments.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.171-171
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• 2021

전 세계적인 기후변화로 인해 홍수가 발생하는 빈도가 상승하고 있으며, 도시화가 발달됨에 따라 재산 피해 금액도 증가하는 추세이다. 이와 같은 홍수피해를 저감시키기 위하여 수공 구조물의 보강 및 설치와 같은 효과적인 구조적 대책이 필수적이다. 구조적 대책의 경우 예방차원의 재난관리를 위하여 치수 사업 전/후의 경제성을 평가해야 하는데, 국내에서는 개선법과 다차원 홍수피해 산정법(MD-FDA, 이하 다차원법)을 활용하여 정량적인 경제성 평가를 수행하고 있다. 그리고 다차원법의 경우 공간정보자료인 토지피복도를 활용하기 때문에 침수된 건물을 각각 산정해줌으로서 보다 정확한 경제성 분석을 실시할 수 있지만 산정 절차가 복잡하여 시간이 오래 걸리는 단점을 지니고 있다. 따라서 본 연구에서는 개선법과 다차원법의 단점을 보완하고자 격자단위 공간정보를 활용한 건물피해 산정방법을 제안하고자 하였다. 국토정보플랫폼에서는 100m×100m 격자 자료를 제공해주고 있으며, 각각의 격자에는 단독 주거, 공동 주거의 공간정보 자료가 구축 되어있다. 이러한 격자자료와 홍수범람지도를 중첩하여 격자 단위 홍수 피해액을 산정함으로서 절차를 간결하게 할 수 있다. 또한 본 연구를 통하여 추정된 피해 금액과 비교적 정확한 홍수 피해액을 추정하는 기존 다차원법의 피해 금액을 비교하여 격자단위 공간정보를 활용한 건물피해 산정방법을 평가하였다. 본 연구를 통하여 개발한 방법을 사용하게 된다면 경제성분석 결과가 과대 산정되는 개선법을 보완할 수 있으며, 계산과정이 복잡하여 실무에서의 적용성이 부족한 다차원법의 문제점도 보완할 수 있을 것으로 판단된다. 또한 신속한 피해액 추정을 통하여 홍수 피해를 예방하는데 필요한 치수사업을 빠르게 선정함으로서 후속 피해를 신속히 예방할 수 있을 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1C
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• pp.1-5
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• 2010

The river maintenance processing has revealed that the river beds in Korea have been significantly polluted in various ways for the last two decades. Thus, the dredging, transportation and landfilling of these contaminated materials are attracting public attention these days. In this study, electrokinetic method was applied in order to accelerate the settling processes of clay particles in suspension and evaluate the factors affecting the settling behaviour. It has been found from the testing results that the settling velocity under the influence of electrokinetics was much faster than the gravitational one, and the water content of slurry soil reduced significantly after the electrokinetic processing. The initial water content of slurry soil should be one of the important factors affecting the settling behaviour as well as variation of water content, and hence the electrokinetic processing would be the cost-effective method for the field application.

• Physical Therapy Rehabilitation Science
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• v.12 no.2
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• pp.167-176
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• 2023

Objective: The purpose of this study was to investigate the effects of anon-contact complex exercise program on muscle strength, fall efficacy, quality of life, and balance ability in older over 65 years of age. Design: A randomized controlled trial Methods: A total of 37 people in older over 65 years of age participated in the study. Random program was conducted and assigned to the experimental group (n=19) and the control group (n=18). Both groups performed the older people welfare center program. In addition, in the experimental group, a non-contact complex exercise program for muscle and balance exercise was performed. All interventions were performed 2 times a week, for a total of 6 weeks. chair stand test (CST), fall efficacy scale (FES), Euro quality of life 5 dimension (EQ-5D), Berg balance scale (BBS), timed up and go test (TUG), Fullerton advanced balance scale (FAB) were measured before and after the intervention to compare their effectiveness. Results: Both groups showed significant differences in CST, FES, EQ-5D, BBS, and TUG before and after intervention (p<0.05). FAB showed significant differences before and after intervention in all items except for FAB 8 and 9 items in the experimental group. In addition, the experimental group showed significant differences in CST, FES, BBS, TUG, FAB (except 1, 7, 8, 9) compared to the control group (p<0.05). Conclusions: The non-contact complex exercise program is an effective intervention method that has clinical significance in improving muscle strength, fall efficacy and static and dynamic balance abilities for the older over 65 years of age.

• Journal of the Korea Institute of Building Construction
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• v.23 no.1
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• pp.1-9
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• 2023

This study is to analyze the cause of the defects in polyurethane waterproofing, a material commonly used on the roof of buildings, and to determine if it has a relation with the curing conditions of humidity and temperature and the moisture content of the base structure. As a result, it was confirmed that the waterproofing coating did not adhere when the moisture content of the base plate was 10% or more. When the temperature and humidity conditions were 20℃ and 80%RH, none of the properties deteriorate but when the temperature was 40℃, 60%RH, air bubbles were formed on the surface, and at 40℃ and 80%RH, the basic properties of the dry coating film were less than the KS F 3211 performance standard.

• Analytical Science and Technology
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• v.20 no.4
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• pp.289-295
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• 2007

A simple electric circuit of an infrared photodiode electrode (IPDE) was utilized to monitor iron using square-wave (SW) anodic stripping voltammetry (SV) and cyclic voltammetry (CV). The optimum analytical conditions were determined and were compared with those of common working electrodes. The comparison showed that CV is more sensitive and convenient to use than the common voltammetry methods. At the optimized conditions, the working ranges of 0.1- to 0.8- and 0.85- to 6.0 mg/L iron was obtained. Relative standard deviation of 15 measurements of iron (0.4 mg/L) was 0.09%. The analytical detection limit was found to be $80{\pm}0.6ug/L$, which was applied to iron in waste water.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.1-5
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• 2014

Acidic chemicals like sulfuric acid, nitric acid and hydrogen chloride take up 37% of the total chemical accidents which took place for the past 10 years. When an acidic chemical leak happens, fume is generated, diffusing into the air, which might cause serious damage to health of local residents and the environment. However, we have only little reference data for production and using of acidic chemicals. In this study, we investigated characteristics of production and using for acidic chemicals with high accident frequency. As a results, domestic chemical accidents were categorized according to chemical types and production, using, and handling characteristics of acidic chemicals were identified. Sulfuric acid was handled in the largest amount, followed in the order of hydrogen chloride, nitric acid, acrylic acid, and hydrogen fluoride. Sulfuric acid is used in the industry of manufacturing composite fertilizer and mainly used for manufacturing fertilizer. Hydrogen chloride is used in the industry of manufacturing basic chemicals for petrochemical family and mainly used for pH regulator. It is expected that this results could be used as preliminary data for making decisions on facilities required intensive management in order to prevent chemical accidents and prepare countermeasures against such accidents.