• International journal of thyroidology
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• v.10 no.1
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• pp.14-23
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• 2017

Background and Objectives: To evaluate and compare the diagnostic performances of grayscale ultrasound (US) and quantitative parameters obtained from texture analysis of grayscale US and elastography images in evaluating patients with diffuse thyroid disease (DTD). Materials and Methods: From September to December 2012, 113 patients (mean age, $43.4{\pm}10.7years$) who had undergone preoperative staging US and elastography were included in this study. Assessment of the thyroid parenchyma for the diagnosis of DTD was made if US features suggestive of DTD were present. Nine histogram parameters were obtained from the grayscale US and elastography images, from which 'grayscale index' and 'elastography index' were calculated. Diagnostic performances of grayscale US, texture analysis using grayscale US and elastography were calculated and compared. Results: Of the 113 patients, 85 (75.2%) patients were negative for DTD and 28 (24.8%) were positive for DTD on pathology. The presence of US features suggestive of DTD showed significantly higher rates of DTD on pathology, 60.7% to 8.2% (p<0.001). Specificity, accuracy, and positive predictive value was highest in US features, 91.8%, 84.1%, and 87.6%, respectively (all ps<0.05). Grayscale index showed higher sensitivity and negative predictive value (NPV) than US features. All diagnostic performances were higher for grayscale index than the elastography index. Area under the curve of US features was the highest, 0.762, but without significant differences to grayscale index or mean of elastography (all ps>0.05). Conclusion: Diagnostic performances were the highest for grayscale US features in diagnosis of DTD. Grayscale index may be used as a complementary tool to US features for improving sensitivity and NPV.

• Science of Emotion and Sensibility
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• v.9 no.4
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• pp.353-366
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• 2006

The aim of this study is to characterize the optical properties of white light-emitting diodes lighting modules and then to evaluate the sensitivity of students and teachers in reacting to the optical properties of these modules. For the sake of this study, each of 5 lighting modules was introduced to the 5 test cabinets. The 5 test cabinets were evaluated and analyzed the student and teacher's sensitivity reaction. We have selected If questions on sensitivity of the lighting and evaluated these questions with semantic differential method. To verify the reliability and objectivity of the questions, the feasibility survey was carried out by a preliminary test. As a result of the test, the sensitivities on the test cabinets were classified the 4 factors, namely, activity as the first factor, stability as the second one , potency as the third one and sensitive image as the fourth one respectively. By the evaluation of student and teacher's sensitivity on the correlated color temperature, they preferred the cabinet with the higher color temperature in view of the activity and potency. And they preferred the cabinet with the lower color temperature in view of the stability factor. In the sensitive image, they preferred the 5800K, bluish white lighting regardless of the color temperature. By the evaluation on the color rendering index, they preferred the cabinet with the higher color rendering index in view of the activity, stability and sensitive image. In the potency factor, they preferred the white lighting with the middle color rendering index.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.49-54
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• 2000

Several soil parameters can be calculated for results of Piezocone test; sensitivity, soil classification, OCR, undrained shear strength, coefficient of consolidation etc., and used to analysis geotechnical problems. Particularly, the coefficient of consolidation which is related to degree of consolidation varies according to rigidity index(I/sub r/). In this study, rigidity index(I/sub r/) was analyzed by Roy's formula. Trixial tests and unconfined compression tests data in the ten sites was analyzed. In conclusion, rigidity index(I/sub r/) was suggested such as rigidity index(I/sub r/) = 15∼60, average rigidity index value(I/sub r/) of approximately 33 within a country.

• Current Optics and Photonics
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• v.5 no.6
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• pp.652-659
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• 2021

The theoretical analysis and optimization of extrinsic Fabry-Perot interferometer (EFPI) opticalfiber humidity sensors are deeply investigated. For a typical dual-cavity structure composed of an optical fiber and a humidity-sensitive membrane (HSM), the changes in refractive index (RI) and initial length are discussed for polymer materials and porous oxide materials when relative humidity (RH) increases. The typical interference spectrum is simulated at different RH using MATLAB. The spectral change caused by changing HSM RI and initial length are simulated simutineously, showing different influences on humidity response. To deeply investigate the influence on RH sensitivity, the typical response sensitivity curves for different HSM lengths and air-cavity lengths are simulated. The results show that the HSM is the vital factor. Short HSM length can improve the sensitivity, but for HSM RI and length the influences on sensitivity are opposite, because of the opposite spectral-shift trend. Deep discussion and an optimization method are provided to solve this problem. According to analysis, an opaque HSM is helpful to improve sensitivity. Furthermore, if using an opaque HSM, a short air cavity and long HSM length can improve the sensor's sensitivity These results provide deep understanding and some ideas for designing and optimizing highly sensitive EFPI fiber humidity sensors.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.6
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• pp.141-150
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• 2021

In order to assess the impact of climate change on irrigation reservoirs, climate exposure (EI), sensitivity (SI), and potential impact (PI) were evaluated for 1,651 reservoirs nationwide. Climate exposure and sensitivity by each reservoir were calculated using data collected from 2011 to 2020 for seven proxy variables (e.g. annual rainfall) and six proxy variables (e.g. irrigation days), respectively. The potential impact was calculated as the weighted sum of climate exposure and sensitivity, and was classified into four levels: 'Low (PI<0.4)', 'Medium (PI<0.6)', 'High (PI<0.8)', and 'Critical (PI≥0.8)'. The result showed that both the climate exposure index and the sensitivity index were on average high in Daegu and Gyeongbuk with high temperature and low rainfall. About 79.8% of irrigation reservoirs in Daegu, Gyeongbuk, and Ulsan with high climate exposure and sensitivity resulted in a 'High' level of potential impact. On the contrary, 64.5% of the study reservoirs in Gyeongnam and Gangwon showed 'Low' in potential impact. In further studies, it is required to reorganize the proxy variables and the weights in accordance with practical alternatives for improving adaptive capacity to drought, and it is expected to contribute to establishing a framework for vulnerability assessment of an irrigation reservoir.

• Child Health Nursing Research
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• v.11 no.3
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• pp.316-321
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• 2005

Purpose: This study was done to evaluate the validity of Korean Denver ll developmental screening test in screening children with developmental risk. Method: The participants in the study were 113 children referred for developmental assessment in the department of rehabilitation of D University hospital. They were examined with the BSID (Bayley Scales of Infant Development) II and Korean Denver II by one occupational therapist. The data was analyzed by $x^2$ test and discriminant analysis. Results: There was a significant relationship between the Mental Developmental Index (MDI) of the BSID II and the result of the Korean Denver II. The sensitivity and specificity of Korean Denver II were 0.87 and 0.62 when abnormal MDI was defined as lower than 85 was used as a diagnosis of developmental delay. There was a significant relationship between the Psychomotor Developmental Index (PDI) of the BSID ll and the result 0.7 Korean Denver ll. The sensitivity and specificity of Korean Denver II were 0.83 and 0.51 The over-all hit ratio was $79.6\%$. Conclusion: The result showed that the Korean Denver II was valid and has good sensitivity and moderate specificity in screening developmental delay.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.1
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• pp.142-154
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• 1994

In this paper, stochastic imperfection sensitivity analyses of stiffened cylindrical shells under static load are presented. Multimode formulation is performed for the buckling load calculation based on the Donnell's theory and Galerkin approximation. Random imperfection field theory and response surface method are combined with deterministic bucking analysis scheme to perform stochastic imperfection sensitivity analyses of stiffened cylindrical shells considering random geometric imperfection. From the characteristics of probabilistic bucking load, the relation between reliability index and safety parameter can be obtained in addition to the relation between load and reliability index. Those results can be used to determine the range of required safety parameter and acceptable imperfection.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.637-643
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• 2015

BACKGROUND/OBJECTIVES: Malnutrition in the elderly is a serious problem, prevalent in both hospitals and care homes. Due to the absence of a gold standard for malnutrition, herein we evaluate the efficacy of five nutritional screening tools developed or used for the elderly. SUBJECTS/METHODS: Elected medical records of 141 elderly patients (86 men and 55 women, aged $73.5{\pm}5.2years$) hospitalized at a geriatric care hospital were analyzed. Nutritional screening was performed using the following tools: Mini Nutrition Assessment (MNA), Mini Nutrition Assessment-Short Form (MNA-SF), Geriatric Nutritional Risk Index (GNRI), Malnutrition Universal Screening Tool (MUST) and Nutritional Risk Screening 2002 (NRS 2002). A combined index for malnutrition was also calculated as a reference tool. Each patient evaluated as malnourished to any degree or at risk of malnutrition according to at least four out of five of the aforementioned tools was categorized as malnourished in the combined index classification. RESULTS: According to the combined index, 44.0% of the patients were at risk of malnutrition to some degree. While the nutritional risk and/or malnutrition varied greatly depending on the tool applied, ranging from 36.2% (MUST) to 72.3% (MNA-SF). MUST showed good validity (sensitivity 80.6%, specificity 98.7%) and almost perfect agreement (k = 0.81) with the combined index. In contrast, MNA-SF showed poor validity (sensitivity 100%, specificity 49.4%) and only moderate agreement (k = 0.46) with the combined index. CONCLUSIONS: MNA-SF was found to overestimate the nutritional risk in the elderly. MUST appeared to be the most valid and useful screening tool to predict malnutrition in the elderly at a geriatric care hospital.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.736-742
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• 2008

This paper proposes new searching algorithm for the optimal PD gains of flexible rotor supported by active magnetic bearings. Under the assumption of linearized bearing parameters with respect to PD gains, the performance index in quadratic form is defined and steepest descent method is adopted for determining local minimum. Moreover, the eigenpair sensitivity concept is utilized to evaluate the sensitivity of performance index. To evaluate the effectiveness of suggested algorithm, the finite element model is constructed and its reduced model is retained in modal domain. Given starting gains, the optimal gains are successfully found and the control performance is demonstrated by simulation to show the efficiency of the proposed method.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.175-177
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• 2008

본 논문에서는 I-PIU를 통해 등기화된 데이터를 취득 이용하여 실시간 계통 감시는 물론 광역정전방지에 대한 방법을 제안하고 있다. 또한 민감도 지수(Sensitivity Factor)를 이용한 취약도 지수(Vulnerability Index)와 실시간 데이터를 이용한 거리계전기 동작을 예측 알고리즘을 적용하여 실시간 계통의 상황감시는 물론 계통의 위험 정도를 미리 알리는 거리 계전기 모니터링 시스템을 설계하였다 이는 운영자로 하여금 개통의 위험 요소를 적절한 조치를 취해 제거함으로써 치명적인 광역 정전 사태의 방지와 효율적 계통관리를 기대 할 수 있다.