• 대한원격탐사학회지
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• 제30권3호
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• pp.341-350
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• 2014

Landsat images can monitor the snow-covered Earth surface variations with the ground resolution of 30m and the multi-spectral bands in the visible, NIR, SWIR and TIR spectral regions for the last 30 years. The Southern Volcanic Zone (SVZ) of Chile consists of many volcanoes, and all of the volcanoes are covered with snow at the top of mountain. Snow cover area in southern province of the SVZ of Chile (37 to $46^{\circ}S$) have been influenced by significant frontal retreats as well as eruptive activities. In this study, we have investigated the changes of the snow-cover area and snow-line elevation at Mt. Villarrica and Mt. Llaima, Chile from three Landsat images acquired on Feb. 1990, 2005 and 2011. The snow-cover areas are 13.42, 26.75 and $21.60km^2$ at Mt. Villarrica in 1990, 2005 and 2011, respectively, and 3.82, 25.12 and $8.89km^2$ at Mt. Llaima in 1990, 2005 and 2011, respectively. The snow-line elevations are 1871, 1738 and 1826m at Mt. Villarrica in 1990, 2005 and 2011, respectively, and 2007, 1822 and 1818m at Mt. Llaima in 1990, 2005 and 2011, respectively. The results indicate that both of the snow-cover and snow-line changes are strongly related with the volcanic activity change. The results demonstrate that the snow-cover area and snow-line elevation changes can be used as an indicator of the volcanic activity at Mt. Villarrica and Mt. Llaima, Chile.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5829-5834
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• 2012

Background: Breast cancer is the most common cancer in women worldwide. Although different metabolic factors have been implicated in breast cancer development, the relationship between hypertension and breast cancer has not been elucidated. Aim: To evaluate hypertension as a risk factor for breast cancer in Chilean women of low and middle socio-economic status. Methods: We conducted an age-matched (1:1) case-control study in 3 hospitals in Santiago, Chile. Breast cancer cases (n=170) were histopathologically confirmed. Controls had been classified as Breast Imaging Reporting and Data System I (negative) or II (benign findings) within 6 months of recruitment. Blood pressure was measured using a mercury sphygmomanometer and standardized procedures. We used 2 hypertension cut-off points: blood pressures of ${\geq}140/90$ mmHg and ${\geq}130/85$ mmHg. Fasting insulin and glucose levels were assessed, and anthropometric, sociodemographic, and behavioral information were collected. Odds ratios and 95% confidence intervals were estimated for the entire sample and restricted to postmenopausal women using multivariable conditional logistic regression models. Results: Hypertension (${\geq}140/90$ mmHg) was significantly higher in cases (37.1%) than controls (17.1%) for the entire sample and in postmenopausal pairs (44.0% compared to 23.8%). In crude and adjusted models, hypertensive women had a 4-fold increased risk of breast cancer (adjusted odds ratio: 4.2; 95% confidence interval: 1.8; 9.6) compared to non-hypertensive women in the entire sample. We found a similar association in the postmenopausal group (adjusted odds ratio: 2.8; 95% confidence interval: 1.1; 7.4). A significant effect was also observed when hypertension was defined as blood pressure of ${\geq}130/85$ mmHg. Conclusion: A significant association was found between hypertension and breast cancer over the entire sample and when restricted to postmenopausal women. Hypertension is highly prevalent in Latin America and may be a modifiable risk factor for breast cancer; therefore, a small association between hypertension and breast cancer may have broad implications.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1485-1488
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• 2016

Background: Chile is one of the countries with the highest prevalence of cholelithiasis worldwide, considering the Mapuche ethnicity as a risk factor for developing this pathology. Moreover, cholelithiasis is the main risk factor for developing gallbladder cancer, being the fifth cause of cancer death in Chile. The purpose of this study was to compare the frequency of cholelithiasis and biliary pathology among the population belonging to Rapanui ethnicity and non-Rapanui population living on Easter Island. Materials and Methods: In this retrospective case-control study, a total of 609 abdominal ultrasonographs performed consecutively in Hanga Roa Hospital during the period August 2012 to January 2015 were analyzed. Multiple logistic regression was used to obtain odds ratio (OR) and 95% confidence intervals (95% CI) of cholelithiasis and biliary pathology, adjusting for age, gender and referral diagnostic hypothesis. Results: In the Rapanui population the frequency for cholelithiasis and biliary pathology was 6.4% and 13%, meanwhile for the non-Rapanui population it was 13% and 22% respectively. Compared to the non-Rapanui Chilean population, the Rapanui ethnicity presented an OR of 0.53 (95% CI: 0.29-0.95) for cholelithiasis and OR of 0.52 (95% CI: 0.33-0.82) for biliary pathology. Conclusions: We found statistically significant ethnic differences in the frequency of cholelithiasis and biliary disease among the population of Rapanui and non-Rapanui ethnicity, so that this could be a protective factor for the development of biliary pathology, given the Chilean population context. Other studies including community population to determine the real prevalence of cholelithiasis and analyze the protective role of Rapanui ethnicity on this disease are necessary.

• Molecules and Cells
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• 제19권3호
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• pp.418-427
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• 2005

When inoculated into sensitive tobacco Xanthi-nn plants, the crucifer and garlic-infecting Tobacco mosaic virus (TMV-Cg) induces local necrotic lesions that resemble those seen in the hypersensitive response (HR) of resistant tobacco plants. However, unlike these, tobacco Xanthi-nn plants do not become resistant to infection and the virus spreads systemically causing a severe disease characterized by necrotic lesions throughout the plant. To identify the viral protein that elicits this necrotic response, we used a set of hybrid viruses constructed by combination of TMV-Cg and the tobacco mosaic virus strain U1 (TMV-U1). In this study we present evidence that the coat protein of TMV-Cg (CPCg) is the elicitor of the necrotic response in tobacco Xanthi-nn plants. Local and systemic necrotic lesions induced by TMV-Cg and by the hybrid U1-CPCg -that carries CPCg in a TMV-U1 context- are characterized by cell death and by the presence of autoflorescent phenolic compounds and $H_2O_2$, just like the HR lesions. In addition, defense-related genes and detoxifying genes are induced in tobacco Xanthi-nn plants after TMV-Cg and U1-CPCg inoculation. We postulate that in our system, CPCg is recognized by sensitive tobacco plants that mount an incomplete defense response. We call this an HR-like since it is not enough to induce plant resistance.

• Archives of Plastic Surgery
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• 제45권3호
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• pp.284-288
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• 2018

Dynamic infrared thermography (DIRT) has been used for the preoperative mapping of cutaneous perforators. This technique has shown a positive correlation with intraoperative findings. Our aim was to evaluate the accuracy of perforator mapping with DIRT and augmented reality using a portable projector. For this purpose, three volunteers had both of their anterolateral thighs assessed for the presence and location of cutaneous perforators using DIRT. The obtained image of these "hotspots" was projected back onto the thigh and the presence of Doppler signals within a 10-cm diameter from the midpoint between the lateral patella and the anterior superior iliac spine was assessed using a handheld Doppler device. Hotspots were identified in all six anterolateral thighs and were successfully projected onto the skin. The median number of perforators identified within the area of interest was 5 (range, 3-8) and the median time needed to identify them was 3.5 minutes (range, 3.3-4.0 minutes). Every hotspot was correlated to a Doppler sound signal. In conclusion, augmented reality can be a reliable method for transferring the location of perforators identified by DIRT onto the thigh, facilitating its assessment and yielding a reliable map of potential perforators for flap raising.

• Smart Structures and Systems
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• 제14권5호
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• pp.883-900
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• 2014

Shape memory alloys (SMA) can dissipate energy through hysteresis cycles without significant residual deformation. This paper describes the fabrication and testing of copper-based SMA hourglass-shaped plates for use in energy dissipation devices and the development of a numerical model to reproduce the experiments. The plates were tested under cyclic flexural deformations, showing stable hysteresis cycles without strength degradation. A detailed nonlinear numerical model was developed and validated with the experimental data, using as input the constitutive relationship for the material determined from cyclic tests of material coupons under tension loading. The model adequately reproduces the experimental results. The study is focused on the exploitation of SMA in the martensite phase.

• Geomechanics and Engineering
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• 제9권3호
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• pp.397-414
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• 2015

Three different applications for monitoring displacements in underground structures using a BOTDR-based distributed optical fiber strain sensing system are presented. These applications are related to the strain measurements of (1) instrumented PVC tube designed to be attached to tunnel side wall and ceiling as a sensor; (2) rock bolts for tunnels; and (3) shotcrete lining under loading. The effectiveness of using the proposed strain sensing system is evaluated by carrying out laboratory tests, in-situ measurements, and numerical simulations. The results obtained from this validation process provide confidence that the optical fiber is able to quantify strain fields under a variety of loading conditions and consequently use this information to estimate the behavior of rock mass during mining activity. As the measuring station can be located as far as 1 km of distance, these alternatives presented may increase the safety of the mine during mining process and for the personnel doing the measurements on the field.

• Ocean Systems Engineering
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• 제13권3호
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• pp.225-245
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• 2023

In the present paper, a numerical and experimental analysis for a wave energy converter under extreme environmental conditions is carried out. After the definition of design waves, including a 100-year return period stochastic sea state and a deterministic rogue wave condition, a numerical analysis using potential theory and a RANS equations solver are compared with experiments carried out at the Seakeeping Basin at the Technical University of Berlin. Results are discussed with special emphasis on the limits of potential theory methods for the evaluation of extreme wave conditions and the use of the presented methodology for early design stages.

• 한국산림과학회지
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• 제88권1호
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• pp.1-10
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• 1999

국내 원목수요량의 대부분을 수입에 의존하고 있는 우리 나라는 해외원목의 안정적 공급이 필수적이다. 이를 위해서는 해외원목시장의 전반적인 동향을 정확히 파악하고 그 움직임을 예측할 수 있는 능력이 무엇보다 중요하다. 따라서 본 연구는 우리 나라의 주요 원목 수입 대상국의 시계열 수입가격을 이용하여 가격들간의 인과관계 규명과 특정 시장의 예상치 못한 외부충격에 대하여 다른 시장들이 어떻게 반응하는 지를 분석하였다. 이를 위하여 벡터자기회귀(VAR) 모형을 추정하여 인과성 검정 및 오차분산분해분석, 충격반응분석을 수행하였다. 그 결과, 우리 나라에 수입되는 원목중 약 40%를 차지하고 있는 뉴질랜드와 러시아 원목수입가격은 과거 자국의 가격에 의해서만 설명될 뿐 다른 나라의 영향을 전혀 받지 않는 것으로 나타났다. 반면 다른 나라들에 있어서는 자체 자국의 수입가격뿐만 아니라 다른 나라들의 수입가격에 영향을 받는 것으로 나타났다. 충격반응분석 결과에 있어서는 뉴질랜드 원목시장에 충격이 발생할 경우 자체시장은 물론 PNG와 미국 원목수입가격에 영향을 미치고, 칠레의 경우에서도 자체시장 뿐만 아니라 러시아, 미국 원목수입가격에 영향을 미치는 것으로 분석되었다. 이외 국가들은 자체가격에서만 민감하게 반응하는 것으로 분석되었다.

• 한국산림과학회지
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• 제90권1호
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• pp.1-9
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• 2001

이 연구는 우리 나라에 수입되는 원목의 시장구조를 밝히기 위하여 미국, 뉴질랜드, 칠레로부터 들어오는 온대침엽수원목에 대한 수입수요를 수출국별 원목의 가격과 국내 목재가공업(제재업)의 제품생산량의 함수로 설정하여 수입원목수요함수를 추정하였다. 이 연구는 당해 연도에 수입되는 각 국가별 수입원목량은 당해 연도의 자체원목가격, 대체 원목가격, 그리고 당해 연도의 제품생산량에 의하여 결정된다고 가정하여 모델을 개발하였다. 1981년부터 1997년까지 17년간의 수입원목량과 가격에 관한 통계자료를 이용하여 SURE(Seemingly Unrelated Regression Equations)추정 방법으로 미국산, 뉴질랜드산 및 칠레산 소나무원목의 수입수요함수를 추정하였다. 미송원목수입가격에 대한 우리 나라의 미송원목, 뉴송원목 그리고 칠레송원목의 수입수요 탄력성은 각각 -2.88, 1.36, 3.17로 추정되어, 미송원목가격이 미송뿐만 아니라 칠레송원목의 수입량에도 크게 영향을 미치는 것으로 나타났다. 뉴송원목 수입가격에 대한 미송원목, 뉴송원목 그리고 칠레송원목의 수입수요 탄력성은 각각 0.71, -1.65, 1.44로 나타나 뉴송가격은 미송원목수입에 크게 영향을 미치지 못하는 것으로 나타났다. 칠레송원목수입가격에 대한 미송원목, 뉴송원목 그리고 칠레송원목의 수입수요 탄력성은 각각 1.02, 0.88, -3.41로 나타나 칠레송원목수입량은 자체가격에 민감하나 뉴송원목수입량이 칠레송 가격에 그리 크게 영향을 받지 않는 것으로 나타났다.