• International Journal of Oral Biology
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• 제38권3호
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• pp.87-92
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• 2013

Periodontal inflammation increases the risk of tooth loss, particularly in cases where there is an associated loss of alveolar bone and periodontal ligament (PDL). Histological and morphometric evaluation of periodontal inflammation is difficult. Especially, the lengths of the periodontal ligament and interdental alveolar bone space have not been quantified. A quantitative imaging procedure applicable to an animal model would be an important clinical study. The purpose of this study was to quantify the loss of alveolar bone and periodontal ligament by evaluation with micro-computed tomography (micro-CT). Another purpose was to investigate differences in infections with systemic E. coli LPS and TNF-${\alpha}$ on E. coli lipopolysaccharide (LPS) in loss of alveolar bone and periodontal ligament model on mice. This study showed that linear measurements of alveolar bone loss were represented with an increasing trend of the periodontal ligament length and interdental alveolar process space. The effects of systemic E. coli LPS and TNF-${\alpha}$ on an E. coli LPS-induced periodontitis mice model were investigated in this research. Loss of periodontal ligament and alveolar bone were evaluated by micro-computed tomography (micro-CT) and calculated by the two- and three dimensional microstructure morphometric parameters. Also, there was a significantly increasing trend of the interdental alveolar process space in E. coli LPS and TNF-${\alpha}$ on E. coli LPS compared to PBS. And E. coli LPS and TNF-${\alpha}$ on E. coli LPS had a slightly increasing trend of the periodontal ligament length. The increasing trend of TNF-${\alpha}$ on the LPS-induced mice model in this experiment supports the previous studies on the contribution of periodontal diseases in the pathogenesis of systemic diseases. Also, our findings offer a unique model for the study of the role of LPS-induced TNF-${\alpha}$ in systemic and chronic local inflammatory processes and inflammatory diseases. In this study, we performed rapidly quantification of the periodontal inflammatory processes and periodontal bone loss using micro-computed tomography (micro-CT) in mice.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1525-1530
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• 2004

Mutagen X (MX) exists in our drinking water as the bi-products of chlorine disinfection. Being one of the most potent mutagen, it attracted much attention from many researchers. MX and its analogs are synthesized and modeled by quantitative structure activity relationship (QSAR) methods. As a result, factors affecting this class of compounds have been found to be steric and electrostatic effects. We tried to collect all the data available from the literature. With both CoMFA and CoMSIA various combinations of physiochemical parameters were systematically studied to produce reasonable 3-dimensional models. The best model for CoMFA gave $q^2$ = 0.90 and $r^2$ = 0.97, while for CoMSIA $q^2$ = 0.85 and $r^2$ = 0.94. So the models seem to be reasonable. Unlike previous result of CoMFA, in our case steric parameter alone gave the best statistics. Although the steric contribution was found to be the most important in both CoMFA and CoMSIA, steric parameter along with electrostatic parameter produced slightly better model in CoMSIA. Overall, steric contribution is clearly the most important single factor. However, when we compare chlorine and bromine substitution, chlorine substitution can be more mutagenic. This indicates that other factors such as electrostatic effect also influence the mutagenicity. From the contour maps, steric contribution seems to be focused on rather small area near C6 substituent of the furanone ring, rather than C3 substituent. Therefore the locality of steric contribution can play a significant role in mutagenicity.

• 대한인간공학회지
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• 제29권6호
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• pp.875-887
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• 2010

The quantitative effectiveness of powered support surfaces such as APAM in preventing and treating pressure ulcers has not been sufficiently evaluated because of uncertainty of alternating pressure load input and lack of interpretation of dynamic perfusion characteristics of soft tissue. The aim was to verify the dynamic loading effects to sacral tissue perfusion characteristics from alternating set pressure changes. We developed integrated experiment system to supply alternating load to supinely positioned sacrum and concurrently measured $TcPO_2$, $TcPCO_2$ and air cell pressure. Ten aged subjects (5 female, 5 male) were tested with alternating set pressure 20, 30, 40, 50 and 60mmHg. From the dynamic perfusion response eight characteristic parameters were proposed such as average, minimum, maximum and perfusion range regarding to $TcPO_2$ and $TcPCO_2$. A one-way ANOVA was carried out to determine whether the manipulation of alternating set pressure had any effect on $TcPO_2$ and $TcPCO_2$. From the dynamic tissue perfusion response we found mean $TcPO_2$ decreased exponentially as alternating pressure load increased and perfusion range varied mainly because of minimum level change of $TcPO_2$. And perfusion range of $TcPCO_2$ affected by increase of maximum value of $TcPCO_2$. From the results we can get more strict insights about actual physiological dynamic tissue perfusion mechanism under alternating pressure load.

• Interdisciplinary Bio Central
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• 제3권4호
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• pp.15.1-15.11
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• 2011

Background: Histone deacetylase (HDAC) 8 is one of its family members catalyzes the removal of acetyl groups from N-terminal lysine residues of histone proteins thereby restricts transcription factors from being expressed. Inhibition of HDAC8 has become an emerging and effective anti-cancer therapy for various cancers. Application computational methodologies may result in identifying the key components that can be used in developing future potent HDAC8 inhibitors. Results: Facilitating the discovery of novel and potential chemical scaffolds as starting points in the future HDAC8 inhibitor design, quantitative structure-activity relationship models were generated with 30 training set compounds using genetic function approximation (GFA) and Bayesian algorithms. Six GFA models were selected based on the significant statistical parameters calculated during model development. A Bayesian model using fingerprints was developed with a receiver operating characteristic curve cross-validation value of 0.902. An external test set of 54 diverse compounds was used in validating the models. Conclusions: Finally two out of six models based on their predictive ability over the test set compounds were selected as final GFA models. The Bayesian model has displayed a high classifying ability with the same test set compounds and the positively and negatively contributing molecular fingerprints were also unveiled by the model. The effectively contributing physicochemical properties and molecular fingerprints from a set of known HDAC8 inhibitors were identified and can be used in designing future HDAC8 inhibitors.

• 한국철도학회논문집
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• 제8권6호
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• pp.520-524
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• 2005

It is consequential to reduce the environmental impact of a product for sustainable development in 21st Century. In the field of transportation, especially, the technological market concerned about reduction and assessment of greenhouse gas emission is expected to be extended. The LCA gas been esteemed and utilized as a realistic alternative greenhouse gas emission is expected to be extended. The LCA has been esteemed and utilized as a realistic alternative to improve the environment by the assessment of environmental impacts. In this study, simplified life cycle assessment(S-LCA), was performed to analyze the environmental impacts quantitatively, which were produced through the life cycle of a electric motor unit(EMU). The object of the present work is rth investigate main parameters of environmental impacts and to establish the plans to improve the environment impact of EMU. As a result of quantitative assessment for environmental impact and manufacturing, the EMU carbody made of SUS showed acidification(AD) and marine water aquatic ecotoxicity(MAET) the most, while that made of Mild showed high impact of global warning(GW) and abiotic resources depletion(ARD). For the SUS EMU, the high AD and MAET impact is occurred by the discharged pollutants during acid-washing process. Also, high value of GW and ARD for Mild EMU is resulted from the consumption of iron ore, coal and crude oil during manufacturing. Therefore, the environment impact of carbody would be decreased by enhancing of energy efficiency and the lightening the weight of it.

• 대한인간공학회지
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• 제25권3호
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• pp.49-60
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• 2006

Technological encroachment provides human operators with flood of information that must be analyzed to understand the environment and make judgments that lead to strategic actions. Further, the environment is not static and therefore uncertain, changing its aspect dynamically. Complexity accompanied with its dynamics imposes substantial difficulty to human operators' task. Criticality of having situational understanding becomes more important than ever. Situationalunderstanding requires the human operators possessing tacit knowledge in order for them to make the sense out of the situation while interacting with information from many heterogeneous sources, the notion of sensemaking. Sensemaking refers to the process of developing mental framework to assemble pieces of information representing different aspects of the environment that can be used to develop one's own actionable knowledge to implement their judgments in the uncertain environment. Therefore, judgment process and performance is a key component of sensemaking process. Among many judgment and decision making models, the lens model with its extension can be utilized to partially describe the judgmental aspect of sensemaking. One of the lens model parameters, unmodeled knowledge, can be a corresponding quantitative measure for the tacit knowledge that plays an important role in sensemaking. In this paper, a comprehensive literature for sensemaking is provided to formally define the notion of sensemaking in the military domain. Also, it is proposed that there is a crucial link between the sensemaking and human judgment process and performance from the lens model perspective. Potential implications for experimental framework are also proposed.

• 한국음향학회지
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• 제35권2호
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• pp.134-142
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• 2016

본 논문에서는 40 kHz 초음파 신호를 입 주변에 쏘고, 되돌아오는 초음파 신호를 이용해 음성신호를 합성하는 방법을 소개하고 성능을 평가하였다. 발성하고 있는 입주변에 초음파를 방사하게 되면, 입술, 턱, 뺨 등의 움직임으로 인한 변위로 도플러 현상이 발생하고, 이에 따라 반사 신호에는 본래의 주파수 성분과는 다른 도플러 주파수가 관찰되는데, 본 논문에서는 이러한 도플러 주파수를 이용하여 음성 파라메터를 추정하도록 하였다. 음성합성에 앞서서 초음파 도플러 신호와 음성 신호 간의 상관관계를 각 주파수 별로 분석하였으며, 이로부터 초음파 도플러 신호를 이용한 음성 신호의 합성 가능성을 살펴보았다. 변환에는 초음파 도플러의 정적, 동적 특성을 함께 반영한 특징 변수를 사용하였으며 결합-혼합 가우시안 기법을 이용하여 음성 파라메터로 변환하였다. 5명의 피 실험자를 이용한 음성 합성 실험에서 필터뱅크 에너지 값을 초음파신호의 특징변수로, LPC(Linear Predictive Coefficient) 켑스트럼 계수를 음성 변수로 사용하는 경우 가장 우수한 변환 성능을 나타내었다. 음성신호에서 추출한 여기신호를 이용하여 합성음을 생성하고, 이를 청취하였을 때 72.2 %의 평균 인식율이 얻어짐을 확인할 수 있었다.

• 폴리머
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• 제33권4호
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• pp.273-283
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• 2009

고분자소재의 표면 특성 중의 하나인 스크래치 거동에 관한 최근의 연구 결과와 현황을 광범위하게 고찰하였다. 본 고찰에서는 고분자 소재의 스크래치 특성에 영향을 주는 실험인자들, 즉 소재재질, 온도, 작용하중, 실험속도, 표면처리, 스크래치 횟수, 고분자 구조 및 관능기, 가교정도 그리고 결정화도에 따른 스크래치 특성을 조사하였다. 또한, 고분자 소재의 스크래치 특성을 정량적으로 평가할 수 있는 접근 방법을 소개하였고, 현존하는 관련 국제시험법을 비교 조사하였다. 고분자 소재의 스크래치 거동을 정확히 평가할 수 있는 방법과 내스크래치성을 향상시킬 수 있는 방법에 관한 최근의 기술적 접근 방법에 대해 토의하였다.

• 플랜트 저널
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• 제12권3호
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• pp.24-31
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• 2016

풍진동(Wind-induced vibration)은 바람에 의해 구조물에 진동이 발생하는 현상으로써 세장비가 큰 열기기 Stack 설계시 고려해야 할 중요한 사항이다. 따라서, 국제 규격에는 풍진동에 대한 설계 인자와 각 범위에 대해 필요한 고려 사항을 정의하고 있다. 규격에 의한 설계 검증은 몇몇 인자를 이용하여 간단하게 확인이 가능하다는 장점이 있는 반면, 실제 풍진동에 의한 영향을 정량적으로 평가하지 않기 때문에 실제 필요한 것보다 과도한 설계를 요구할 수 있다는 단점이 있다. 또한 여러 제약조건으로 Code 상의 요구조건을 만족하지 못하는 경우 실제 시스템의 거동을 예측할 수 없다는 단점이 있다. 이러한 점을 보완하기 위해 CFD 와 FEM 등의 수치적 해석 방법을 통해 풍진동이 실제 Stack에 미치는 영향을 해석하여 설계 적정성을 검증하여 Code 상의 요구 조건과 비교하였다.

• 한국수자원학회논문집
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• 제39권12호
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• pp.1031-1042
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• 2006

최근 유역과 하천개발사업에 대한 관심이 높아지고 있다. 이러한 배경하에서 본 논문은 실험선택법(choice experiment)을 적용하여 안양천의 속성별 가치를 추정하고 추정된 가치를 적용하여 안양천 물순환 건전화를 위한 대안의 경제적 가치를 추정하였다. 실험선택법은 여러 속성으로 구성된 환경재의 가치추정방법으로 응답자의 선호체계에 명확하게 초점을 둔 지불의사 유도방법이다. 예비조사를 통해 안양천이 가진 속성을 홍수피해위험, 유지유량, 수질, 하천형태, 안양천 개선분담금으로 설정하였다. 서울시와 경기도 지역 거주민 200명을 설문조사하였고 조건부로짓 모형을 적용하여 각 속성에 따른 수준별 가구당 매월 잠재가치를 추정하였다. 본 논문은 정책결정자들에게 하천개발 사업과 관련한 의사결정과정에 유용한 방법론적 체계와 정량적 정보를 제공할 것으로 기대된다.