• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.65-71
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• 2016

Although high mammographic density is one of the strongest predictors of breast cancer risk, X-ray based mammography cannot be performed before the recommended screening age, especially not in adolescents and young women. Therefore, new techniques for breast density measurement are of interest. In this pilot study in Guam and Hawaii, we evaluated a radiation-free, bioimpedance device called Electrical Breast Densitometer$^{TM}$ (EBD; senoSENSE Medical Systems, Inc., Ontario, Canada) for measuring breast density in 95 women aged 31-82 years and 41 girls aged 8-18 years. Percent density (PD) was estimated in the women's most recent mammogram using a computer-assisted method. Correlation coefficients and linear regression were applied for statistical analysis. In adult women, mean EBD and PD values of the left and right breasts were $230{\pm}52$ and $226{\pm}50{\Omega}$ and $23.7{\pm}15.1$ and $24.2{\pm}15.2%$, respectively. The EBD measurements were inversely correlated with PD ($r_{Spearman}=-0.52$, p<0.0001); the correlation was stronger in Caucasians ($r_{Spearman}=-0.70$, p<0.0001) than Asians ($r_{Spearman}=-0.54$, p<0.01) and Native Hawaiian/Chamorro/Pacific Islanders ($r_{Spearman}=-0.34$, p=0.06). Using 4 categories of PD (<10, 10-25, 26-50, 51-75%), the respective mean EBD values were $256{\pm}32$, $249{\pm}41$, $202{\pm}46$, and $178{\pm}43{\Omega}$ (p<0.0001). In girls, the mean EBD values in the left and right breast were $148{\pm}40$ and $155{\pm}54{\Omega}$; EBD values decreased from Tanner stages 1 to 4 ($204{\pm}14$, $154{\pm}79$, $136{\pm}43$, and $119{\pm}16{\Omega}$ for stages 1-4, respectively) but were higher at Tanner stage 5 ($165{\pm}30{\Omega}$). With further development, this bioimpedance method may allow for investigations of breast development among adolescent, as well as assessment of breast cancer risk early in life and in populations without access to mammography.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.36.1-36.7
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• 2015

Background: This study was performed to evaluate three-dimensional positional change of the condyle using three-dimensional computed tomography (3D-CT) following unilateral sagittal split ramus osteotomy (USSRO) in patients with mandibular prognathism. Methods: This study examined two patients exhibiting skeletal class III malocclusion with facial asymmetry who underwent USSRO for a mandibular setback. 3D-CT was performed before surgery, immediately after surgery, and 6 months postoperatively. After creating 3D-CT images by using the In-vivo $5^{TM}$ program, the axial plane, coronal plane, and sagittal plane were configured. Three-dimensional positional changes from each plane to the condyle, axial condylar head axis angle (AHA), axial condylar head position (AHP), frontal condylar head axis angle (FHA), frontal condylar head position (FHP), sagittal condylar head axis angle (SHA), and sagittal condylar head position (SHP) of the two patients were measured before surgery, immediately after surgery, and 6 months postoperatively. Results: In the first patient, medial rotation of the operated condyle in AHA and anterior rotation in SHA were observed. There were no significant changes after surgery in AHP, FHP, and SHP after surgery. In the second patient, medial rotation of the operated condyle in AHA and lateral rotation of the operated condyle in FHA were observed. There were no significant changes in AHP, FHP, and SHP postoperatively. This indicates that in USSRO, postoperative movement of the condylar head is insignificant; however, medial rotation of the condylar head is possible. Although three-dimensional changes were observed, these were not clinically significant. Conclusions: The results of this study suggest that although three-dimensional changes in condylar head position are observed in patients post SSRO, there are no significant changes that would clinically affect the patient.

• 한국측량학회지
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• 제32권6호
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• pp.651-659
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• 2014

With the popularization of big data environment, big data have been highlighted as a key information strategy to establish national spatial data infrastructure for a scientific land policy and the extension of the creative economy. Especially interesting from our point of view is the cadastral information is a core national information source that forms the basis of spatial information that leads to people's daily life including the production and consumption of information related to real estate. The purpose of our paper is to suggest the scheme of big data analytics with respect to the articles of cadastral resurvey project in order to approach cadastral information in terms of spatial data integration. As specific research method, the TM (Text Mining) package from R was used to read various formats of news reports as texts, and nouns were extracted by using the KoNLP package. That is, we searched the main keywords regarding cadastral resurvey, performing extraction of compound noun and data mining analysis. And visualization of the results was presented. In addition, new reports related to cadastral resurvey between 2012 and 2014 were searched in newspapers, and nouns were extracted from the searched data for the data mining analysis of cadastral information. Furthermore, the approval rating, reliability, and improvement of rules were presented through correlation analyses among the extracted compound nouns. As a result of the correlation analysis among the most frequently used ones of the extracted nouns, five groups of data consisting of 133 keywords were generated. The most frequently appeared words were "cadastral resurvey," "civil complaint," "dispute," "cadastral survey," "lawsuit," "settlement," "mediation," "discrepant land," and "parcel." In Conclusions, the cadastral resurvey performed in some local governments has been proceeding smoothly as positive results. On the other hands, disputes from owner of land have been provoking a stream of complaints from parcel surveying for the cadastral resurvey. Through such keyword analysis, various public opinion and the types of civil complaints related to the cadastral resurvey project can be identified to prevent them through pre-emptive responses for direct call centre on the cadastral surveying, Electronic civil service and customer counseling, and high quality services about cadastral information can be provided. This study, therefore, provides a stepping stones for developing an account of big data analytics which is able to comprehensively examine and visualize a variety of news report and opinions in cadastral resurvey project promotion. Henceforth, this will contribute to establish the foundation for a framework of the information utilization, enabling scientific decision making with speediness and correctness.

• 한국농림기상학회지
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• 제3권4호
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• pp.215-219
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• 2001

기후변화 예측 및 영향평가, 수치대기모형의 개선, 농업 및 산림생태계 관리 등 지역 및 지구규모에서 최신의 지표피복정보를 요구하고 있으나 NOAA-AVHRR을 이용하는 기존의 분류체계에서는 우리나라의 주요 식생인 벼논이 독립적으로 분류되지 못했다. Landsat-TM 등 상업적 위성자료를 이용할 경우 벼논의 정밀한 분류가 가능하나 갱신에 많은 노력과 시간이 필요하여 실용적이지 못하다. 본 실험에서는 쉽게 구할 수 있는 NOAA-AVHRR자료를 사용하되, 벼 군락의 시기별 분광특성차를 벼논피복의 검출에 이용하여 간단하면서도 신뢰성 있는 결과를 얻었다. 5월과 8월의 식생지수값의 지리적 분포특성에 근거하여 각각 유사한 특성을 가진 4개 그룹(도시, 삼림, 수역, 농경지)으로 나누고, 8월에 삼림으로 분류된 화소들 가운데 5월에는 수역으로 분류되는 화소들만 발췌하여 벼논으로 간주하는 방법이다. 이 방법에 의해 벼논으로 분류된 화소들을 1,455개 읍면 단위로 취합하여 재배 면적 및 그 분포를 농림부 통계자료와 비교한 결과 이 방법이 USGS의 분류방법 보다 정확하며 신뢰성이 있는 것으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제34권1호
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• pp.30-37
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• 2009

본 연구의 목적은 복합레진의 광중합 전 열처리가 복합레진의 일부 물성에 미치는 영향을 평가하는 것이다. 우식이 없는 여든 개의 발거된 치아를 사용하였다. 네 가지 온도의 복합레진, 즉, 냉장 보관되어 있던 $4^{\circ}C$ 복합레진, 상온 $17^{\circ}C$의 복합레진, $Calset^{TM}$를 이용하여 $48^{\circ}C$까지 전열처리한 복합레진, 그리고 $56^{\circ}C$까지 전열처리한 복합레진을 사용하였다. 복합레진의 물성으로서 치질과의 전단결합강도, 미세경도, 그리고 이중결합 전환율을 측정하였다. 법랑질과 상아질에서 공히 $4^{\circ}C$, $17^{\circ}C$, $48^{\circ}C$, 그리고 $56^{\circ}C$의 온도 중에서 $56^{\circ}C$까지 전열처리한 복합레진이 가장 높은 전단결합강도를 보였으며, 복합레진의 온도가 높을수록 더 높은 전단결합강도를 나타내었다. 복합레진의 온도가 높을수록 더 높은 미세경도를 나타내었다. 복합레진의 온도가 높을수록 이중결합의 전환율이 더 높게 나타났다. 제한된 여건에서 행해진 본 연구의 결과를 통하여 볼 때, 냉장고 또는 실온에 보관되어 있던 복합레진을 미리 열처리하면 치질과의 전단결합강도, 복합레진의 미세경도 및 이중결합 전환율이 증가할 것으로 보인다. 따라서 임상에서 복합레진을 사용 시 복합레진의 물성을 향상시키기 위하여 레진을 미리 열처리하는 것을 추천할 수 있겠다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.287-295
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• 2005

In order to compare bacteria] community structure and diversity in activated sludges, terminal restriction fragment length polymorphism (T-RFLP) of PCR-amplified 16s rDNAs was analyzed for 31 domestic and industrial wastewater treatment plants (WTPs). Regardless of the characteristics of the wastewaters, the bacteria] community structures of activated sludges appeared diverse and complex. In particular, activated sludges in domestic WTPs contained higher bacterial diversity than those in industrial WTPs. It was also found that terminal restriction fragment (T-RF) profiles derived from domestic WTPs were very similar with each other, although activated sludges were collected from different plants at different locations. Interestingly, activated sludges of a WTP where restaurant and toilet sewages of a company were managed showed a bacterial community structure similar to that of domestic WTPs. Activated sludges in leather industria] WTPs also showed a high similarity. However, other wastewaters possessed different bacterial communities, so that overall similarity was as low as about $30\%$. Since activated sludges from WTPs for domestic wastewaters and a company sewage appeared to hold similar bacterial communities, it was necessary to confirm if similar wastewaters induce a similar bacterial community. To answer this question, analysis of T-RFs for activated sludges, taken from another 12 domestic WTPs, was conducted by using a 6­FAM$^{TM}$-Iabeled primer and an automated DNA sequencer for higher sensitivity. Among 12 samples, it was again found that T-RF profiles of activated sludges from Yongin, Sungnam, Suwon, and Tancheon domestic WTPs in Kyonggi-do were very similar with each other. On the other hand, T-RF profiles of activated sludges from Shihwa and Ansan WTPs were quite different from each other. It was thought that this deviation was caused by wastewaters, since Ansan and Shihwa WTPs receive both domestic and industrial wastewaters. From these results, it was tentatively concluded that similar bacterial communities might be developed in activated sludges, if WTPs treat similar wastewaters.

• 감성과학
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• 제12권1호
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• pp.77-86
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• 2009

자동차는 첨단공업 기술이 고도로 집적되어 있는 인간-기계 시스템(man machine system)이다. 자동차에 대한 새로운 감성요구를 실현하기 위해서는 인체와 오랜 시간 접촉해 있는 시트 표피재의 분석이 반드시 필요하다. 본 연구에서는 자동차 시트 표피재의 역학적 특성과 감성을 고려한 고급감을 예측하여 고감성 내장 표피재 개발에 기여하고자 한다. 감성용어는 Softness(유연한), Elasticity(탱글탱글한), Volume(풍성한), Stickiness (끈끈한)를 설정하였으며, 이와 대응하는 표피재의 역학적 특성 치를 측정하였다. 피혁의 특성평가에 의한 결과로 resilience, bending moment, thickness와 friction 값을 얻을 수 있었으며, 이러한 역학적 특성 치를 softness, elasticity, volume, stickiness 값으로 변화하기 위해 fuzzy logic을 사용하였다. 또한 Fuzzy logic의 결과인 Softness, Elasticity, Volume, Stickiness 값으로 피혁의 고급감을 예측하기 위한 신경망 모델(Neural network)을 구성하였다. 즉, 자동차 표피재 중 피혁의 4가지 물리량으로 인간의 감성인 표피재의 고급감을 예측하여 고감성 자동차 시트 표피재의 개발을 위한 예측 모델의 가능성을 평가하였다.

• Imaging Science in Dentistry
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• 제34권3호
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• pp.151-157
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• 2004

Purpose : To evaluate the quantitative accuracy of three-dimensional (3D) images by means of comparing distance measurements on the 3D images with direct measurements of dry human skull according to slice thickness and scanning modes. Materials and Mathods : An observer directly measured the distance of 21 line items between 12 orthodontic landmarks on the skull surface using a digital vernier caliper and each was repeated five times. The dry human skull was scanned with a Helical CT with various slice thickness (3, 5, 7 mm) and acquisition modes (Conventional and Helical). The same observer measured corresponding distance of the same items on reconstructed 3D images with the internal program of V-works 4.0/sup TM/(Cybermed Inc., Seoul, Korea). The quantitative accuracy of distance measurements were statistically evaluated with Wilcoxons' two-sample test. Results: 11 line items in Conventional 3 mm, 8 in Helical 3mm, 11 in Conventional 5mm, 10 in Helical 5mm, 5 in Conventional 7mm and 9 in Helical 7mm showed no statistically significant difference. Average difference between direct measurements and measurements on 3D CT images was within 2mm in 19 line items of Conventional 3mm, 20 of Helical 3mm, 15 of Conventional 5mm, 18 of Helical 5mm, II of Conventional 7mm and 16 of Helical 7mm. Conclusion: Considering image quality and patient's exposure time, scanning protocol of Helical 5mm is recommended for 3D image analysis of the skull in CT.

• 대한치과보철학회지
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• 제44권3호
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• pp.284-294
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• 2006

Statement of problem. Proliferation of Candida albicans is primarily within the plaque on the fitting surface of the denture rather than on the inflamed mucosa. Consequently, the treatment of the denture is equally important as treatment of the tissue. Cleansing and disinfection should be efficiently carried-out as the organisms can penetrate into the voids of the acrylic resin and grow in them, from which they can continue to infect and reinfect bearing tissues. Purpose. The purpose of this study was to evaluate the applicability of photocatalytic reaction to eliminate Candida albicans from acrylic resin denture base, and to investigate the anti-fungal effect with various UVA illumination time. Materials and Methods. The specimens were cured by the conventional method following the manufacturer's instruction using thermal polymerized denture base resin (Vertex RS: Dentimex, Netherlands). $TiO_2$ photocatalyst sol(LT), which is able to be coated at normal temperature, was made from the Ti-alkoxide progenitor. The XRD patterns, TEM images and nitrogen absorption ability of the $TiO_2$ photocatalyst sol(LT) were compared with the commercial $TiO_2$ photocatalyst P-25. The experimental specimens were coated with the mixture of the $TiO_2$ photocatalyst sol(LT) and binder material (silane) using dip-coater, and uncoated resin plates were used as the control group. Crystallinity of $TiO_2$ of the specimen was tested by the XRD. Size, shape and chemical compositions were also analyzed using the FE-SEM/ EDS. The angle and methylene blue degradation efsciency were measured for evaluating the photocatalytic activity of the $TiO_2$ film. Finally, the antifungal activity of the specimen was tested. Candida albicans KCTC 7629(1 ml, initial concentration $10^5$ cells/ ml) were applied to the experiment and control group specimens and subsequently two UVA light source with 10W, 353 nm peak emission were illuminated to the specimens from 15cm above. The extracted $2{\mu}l$ of sample was plated on nutrient agar plate ($Bacto^{TM}$ Brain Heart Infusion; BD, USA) with 10 minute intervals for 120 minute, respectively. It was incubated for 24 hours at $37^{\circ}C$ and the colony forming units (CFUs) were then counted. Results. Compared the characteristics of LT photocatalyst with commercial P-25 photocatalyst, LT were shown higher activity than P-25. The LT coated experimental specimen surface had anatase crystal form, less than 20 nm of particle size and wide specific surface area. To evaluate the photocatalytic activity of specimens, methylene blue degradation reaction were used and about 5% of degradation rate were measured after 2 hours. The average contact angle was less than $20^{\circ}$ indicating that the LT photocatalyst had hydrophilicity. In the antifungal activity test for Candida albicans, 0% survival rate were measured within 30 minute after irradiation of UVA light. Conclusion. From the results reported above, it is concluded that the UVA-LT photocatalytic reaction have an antifungal effect on the denture surface Candida albicans, and so that could be applicable to the clinical use as a cleaning method.

• 한국콘텐츠학회논문지
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• 제14권9호
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• pp.362-370
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• 2014

본 연구는 자유로운 호흡 상태에서 사이버나이프 영상유도 방사선 치료장치(IGRT)를 이용하여 흉 복부 종양의 움직임과 외부호흡과의 상관관계 측정하여 분석하였다. 대상은 방사선 치료를 시행한 폐종양(n=10), 간종양(n=10), 췌장암(n=10) 환자 총 30명으로, 종양추적시스템(MTS)의 로그 데이터를 변환하여 분석하였다. 자유로운 호흡 중에서 폐종양과 외부호흡의 Peason 상관관계는 두미 방향 0.646(p<0.05), 좌우 방향 0.365(p<0.088), 전후 방향 0.196(p<0.115)로 나타났다. 간종양의 상관관계는 두미 방향 0.841(p<0.000), 좌우 방향 0.346 (p<0.179), 전후 방향 0.691(p<0.001)로 나타났다. 췌장 종양의 상관관계는 두미 방향 0.683(p<0.000), 좌우 방향에서는 0.397(p<0.006), 전후 방향 0.268(p<0.127)로 나타났다. 영상유도장치를 이용한 흉 복부 종양의 움직임 측정 결과는 정확한 치료 체적의 결정에 유용하게 적용할 수 있을 것이다. 또한 외부 호흡과 내부 종양 움직임의 상관관계를 분석을 통하여 다양한 방사선 치료 기술에서 종양의 움직임을 보상해 줄 수 있는 중요한 정보를 제공할 것이다.