• KIEAE Journal
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• v.10 no.6
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• pp.97-103
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• 2010

Sky simulator is a effective daylighting design tool that can evaluate three dimensional performance of lighting. Especially, the dome type sky simulator offer reliable and reproducible daylighting performance with different standard sky models. Recently, K university has developed the dome type sky simulator(sky dome) with the diameter of 6.5m and the height of 3.7m. The sky dome consists of a group of 145 large steel panels with 72 halogen lamps which are arranged in a circular array. The luminance distribution of the sky dome can be calibrated by changing the angle and the brightness of the lamps respectively. To allow more reliable prediction and evaluation of daylighting through the sky dome, It is essential to validate the sky luminance distribution of the sky dome. This study consider the validation of the comparisons between the measured and the calculated luminance values for the CIE standard overcast sky. Also, the error rate between the measured and the calculated luminance values were compared to the previous studies. The results indicated that the K university sky dome can reproduce reliable CIE standard overcast sky with the average relative error rate of 4.4% and root-mean-square error(RMSE) of 5.4%.

• Journal of The Geomorphological Association of Korea
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• v.23 no.2
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• pp.109-125
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• 2016

This study aims to identify the landslide susceptible zones of Boeun area and provide reliable landslide susceptibility maps by applying different modeling methods. Aerial photographs and field survey on the Boeun area identified landslide inventory map that consists of 388 landslide locations. A total ofseven landslide causative factors (elevation, slope angle, slope aspect, geology, soil, forest and land-use) were extracted from the database and then converted into raster. Landslide causative factors were provided to investigate about the spatial relationship between each factor and landslide occurrence by using fuzzy set and logistic regression model. Fuzzy membership value and logistic regression coefficient were employed to determine each factor's rating for landslide susceptibility mapping. Then, the landslide susceptibility maps were compared and validated by cross validation technique. In the cross validation process, 50% of observed landslides were selected randomly by Excel and two success rate curves (SRC) were generated for each landslide susceptibility map. The result demonstrates the 84.34% and 83.29% accuracy ratio for logistic regression model and fuzzy set model respectively. It means that both models were very reliable and reasonable methods for landslide susceptibility analysis.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.33-43
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• 2019

A comparison between sea trial measurements and full-scale CFD results is presented for two self-propelled ships. Two ships considered in the present study are: a general cargo carrier at Froude number $F_n=0:182$ and a car carrier at $F_n=0:254$. For the general cargo carrier, the propeller rotation rate is fixed and the achieved speed and trim are compared to sea trials, while for the car carrier, the propeller rotation rate is adjusted to achieve the 80% MCR. In addition, three grids are used for each ship in order to assess the grid refinement sensitivity. All simulations are performed using the Naval Hydro pack based on foam-extend, a community driven fork of the OpenFOAM software. The results demonstrate the possibility of using high-fidelity numerical methods to directly calculate ship scale flow characteristics, including the effects of free surface, non-linearity, turbulence and the interaction between propeller, hull and the flow field.

• Health Policy and Management
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• v.11 no.1
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• pp.1-18
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• 2001

The purpose of the present study was to assess the agreement of survival probability estimated by International Classification of Diseases l0th Edition(ICD-10) based International Classification of Diseases based Injury Severity Score(ICISS) with professional panel's judgment on preventable death. ICISS has a promise as an alternative to Trauma and Injury Severity Score(TRISS) which have served as a standard measure of trauma severity, but requires more validation studies. Furthermore as original version of ICISS was based ICD-9CM, it is necessary to test its performance employing ICD-10 which has been used in Korea and is expected to replace ICD-9 in many countries sooner or later. Methods : For 1997 and 1998 131 trauma deaths and 1,785 blunt trauma inpatients from 6 emergency medical centers were randomly sampled and reviewed. Trauma deaths were reviewed by professional panels with hospital records and survival probability of trauma inpatients was assessed using ICD-10 based ICISS. For trauma mortality degree of agreement between ICISS survival probability with judgment of professional panel on preventable death was assessed and correlation between W-score and preventable death rate by each emergency medical center was assessed. Results : Overall agreement rate of ICISS survival probability with preventable death judged by professional panel was 66.4%(kappa statistic 0.36). Spearman's correlation coefficient between W-score and preventable death rate by each emergency medical center was -0.77(p=0.07) and Pearson's correlation coefficient between them was -0.90(p=0.01). Conclusions : The agreement rate of ICD-10 based ICISS survival probability with of professional panel's judgment on preventable death was similar to TRISS. The W-scores of emergency medical centers derived from ICD-10 based ICISS were highly correlated with preventable death rates of them with marginal statistical significance.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.438-443
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• 2008

Fire model shall be verified and validated to reliably show the predictive capabilities for a specific use. In the process of model verification and validation, both the acceptable uses and limitation of fire model are established. In this study, the results of FDS simulation are compared with the data of PRISME experiment such as temperature, heat release rate, heat flux, product concentrations in the under-ventilated two-room condition. Furthermore, the sensitivity of FDS under ventilation condition changes are evaluated. FDS provide the reliable prediction for under-ventilated two-room fire scenario with slightly deviation.

• International journal of advanced smart convergence
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• v.2 no.2
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• pp.36-39
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• 2013

It is becoming more important as the growing of health information and increasing in cancer patients diagnose over the time gradually. Among the various types of cancer, we focuses on breast cancer diagnosis. The accuracy of breast cancer diagnosis is increasing when the diagnosis is based on evidence and statistics. To do this we use the weka data mining tools and analysis algorithms significantly associated with the decision tree uses rules. In addition, the data pre-processing and cross-validation are used to increase the reliability of the results. The number and cause of the disease becomes important to increase evidence-based medical doctors. As the evidence-based medical, the data obtained from patients in the past through the disease by calculating the probability for future patients to diagnose and predict disease and treatment plan. It can be found by improving the survival rate plays an important role.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.5
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• pp.716-723
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• 2002

Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model (TRM) was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than 7$^{\circ}C$. The influence of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, was examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found available for this system as well. After validation, the cooling effect was surveyed in terms of motor power, and cooling-air and -water flow rate.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.96-101
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• 2001

Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than $7^{\circ}C$. The influence of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, was examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found available for this system as well. After validation, the cooling effect was surveyed in terms of motor power, and cooling-air flow rate.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.832-834
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• 2004

특징점 기반 지문 인식 시스템은 지문의 특징점 정보를 사용하기 때문에 교문 획득 시 발생하는 거짓 특징점에 많은 영향을 받는다. 거짓 특징점의 제거를 위해 특징정의 이웃 융선을 추적하는 위상 검증 방법(Topological validation)은 거짓 특징점 제거에 뛰어난 효율을 보이지만 올바른 특징점까지 제거되는 단점이 있다. 본 논문에서는 올바른 특징점이 거짓 특징점으로 오판되어 제거되는 것을 줄이기 위챈 가보 필터를 사용하여 특징점 주위 영역을 특징점 방향과 특징점 방향에 수직인 방향으로 필터링 수행 후 특징값의 차를 구하여 특징점의 품질을 평가하였다. 특징값이 일정 기준을 넘는 좋은 품질의 영역에서 추출된 특징점이면 거짓 특징점 제거 알고리즘을 수행하지 않음으로써 올바른 특징점이 제거되는 것을 막을 수 있었고 이와 같이 추출된 특징점들을 이용해 실험한 결과 ERR(Equal eRror Rate)에서 1.7%의 성능 향상을 보였다.

• International Journal of Contents
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• v.17 no.4
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• pp.79-90
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• 2021

With the deepening of population aging, pension has become an urgent problem in most countries. Community smart pension can effectively resolve the problem of traditional pension, as well as meet the personalized and multi-level needs of the elderly. To predict the pension intention of the elderly in the community more accurately, this paper uses the decision tree classification method to classify the pension data. After missing value processing, normalization, discretization and data specification, the discretized sample data set is obtained. Then, by comparing the information gain and information gain rate of sample data features, the feature ranking is determined, and the C4.5 decision tree model is established. The model performs well in accuracy, precision, recall, AUC and other indicators under the condition of 10-fold cross-validation, and the precision was 89.5%, which can provide the certain basis for government decision-making.