• Journal of the Society of Naval Architects of Korea
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• v.60 no.2
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• pp.110-119
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• 2023

The prediction of ship resistance performance is typically obtained by Computational Fluid Dynamics (CFD) simulations or model tests in towing tank. However, these methods are both costly and time-consuming, so hull-form designers use statistical methods for a quick feed-back during the early design stage. It is well known that results from statistical methods are often less accurate compared to those from CFD simulations or model tests. To overcome this problem, this study suggests a new approach using a Convolution Neural Network (CNN) with voxelized hull-form data. By converting the original Computer Aided Design (CAD) data into three dimensional voxels, the CNN is able to abstract the hull-form data, focusing only on important features. For the verification, suggested method in this study was compared to a parametric method that uses hull parameters such as length overall and block coefficient as inputs. The results showed that the use of voxelized data significantly improves resistance performance prediction accuracy, compared to the parametric approach.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.3
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• pp.467-484
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• 2024

This study aimed to enhance the design of cropped t-shirts to improve fit satisfaction among women in their 20s by tailoring the t-shirts to diverse body types. Body types were categorized using Size Korea's 8th Human Body Measurement Data, and statistical analysis was conducted based on the Statistical Package for the Social Sciences (version 26.0). This study also reviewed the literature on t-shirts and fit, the application of pattern and design improvements for different body types, verifying fit and size for each body type, and applying virtual fit effects using geometric forms. Frequency analysis and non-parametric verification were conducted using the Friedman test. The results showed that t-shirts with a horizontal rectangular shape was an effective design and that t-shirts with an inverted triangular structure also had a positive effect. In contrast, square t-shirts exhibited minimal effectiveness. These findings are expected to contribute to the consideration of customized shapes according to body type in t-shirt design. Research on customized virtual cropped t-shirts reflecting various body types can expand fit satisfaction studies, particularly amid the increasing trend of online shopping.

• Journal of Korean Society of Rural Planning
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• v.18 no.4
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• pp.117-127
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• 2012

The demand of rural tourism industry has increased among the urbanites in South Korea, in due to the increase of leisure activity and the emergence of ageing society. Rural amenity resources are gaining various interests, in the value creation and promotion of tourism. In this study, the propensities of city dwellers were separated by life-style classification, and each affinity to the rural amenity resources was examined in accordance with the separation. A questionnaire survey of urbanites in the southern area of Gyeonggi-do, the most populous province in South Korea, was conducted to analyze the preference of city dwellers about rural amenity resource and life-style of themselves. For statistical verification, $IBM^{(R)}$ $SPSS^{(R)}$ Statistics 20 software was used for frequency, reliability, factor and multiple regression analysis of this research. The results of the statistical analyses found a noticeable characteristic in life-style classification. The affinities of urbanites can be classified into four congregations of life-style factors in this statistical model. Each congregation of the factors was named as 'Self-development-oriented', 'Leisure-oriented', 'Achievement-oriented', and 'Culture-oriented' life-style, to represent the characteristics for convenience' sake. Among these styles, only 'Self-development-oriented' and 'Achievement-oriented' showed the positive correlation with rural amenity resources in the multiple regression analysis. In addition, the rural amenity resources were also analyzed in accordance with the life-styles classification of urbanites. City dwellers showed the highest interest to the 'natural resource management facility resource' in natural resources, the 'traditional heritage resource' in cultural resources, and the 'community resource' in social resources. Meanwhile, they showed less interest to 'agricultural and scenery resources' in natural resources, 'specialty production resource' in cultural resources, and 'cooperative farming' in social resources. These characteristics can be constructed as meaning that the urbanites who concern self-development and achievement of their lives have high interest in rural amenity resources, and the main interest of them is not 'return-to-the-farm'(歸農) but 'return-to-the-home'(歸村).

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.447-474
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• 2018

The purpose of this study is to build a new dataset of spatially interpolated climate data of South Korea by performing various geo-statistical interpolation techniques for comparison with the LDAPS grid data of KMA. Among 595 observation data in 2017, 80 % of the total points and remaining 117 points were used for spatial mapping and quantification,respectively. IDW, cokriging, and kriging were performed via the ArcGIS10.3.1 software and Python3.6.4, and each result was then divided into three clusters and four watersheds for statistical verification. As a result, cokriging produced the most suitable grid climate data for instantaneous temperature. For 1-hr accumulated precipitation, IDW was most suitable for expressing local rainfall effects.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.236-241
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• 2010

This paper presents a wear diagnosis method for centrifugal impellers by using an accelerometer. The features are calculated from raw and wavelet transformed signals with several statistical methods applied in time or frequency domains. From the effectiveness coefficient test, it is shown that 7th level of wavelet transformed signal is suitable for wear classification problems. A neural network with 5 feature sets is applied to diagnose the wear magnitude of pump impellers. The verification result reveals that high accuracy for the wear diagnosis of impellers can be obtained by using wavelet features transformed from acceleration signals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.524-539
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• 2014

To investigate schemes of secret key generation from Ultra-wideband (UWB) channel, we study a statistical characterization of UWB outdoor channel for a campus playground scenario based on extensive measurements. Moreover, an efficient secret key generation mechanism exploiting multipath relative delay is developed, and verification of this algorithm is conducted in UWB Line-of-sight (LOS) outdoor channels. For the first time, we compare key-mismatch probability of UWB indoor and outdoor environments. Simulation results demonstrate that the number of multipath proportionally affects key generation rate and key-mismatch probability. In comparison to the conventional method using received signal strength (RSS) as a common random source, our mechanism achieves better performance in terms of common secret bit generation. Simultaneously, security analysis indicates that the proposed scheme can still guarantee security even in the sparse outdoor physical environment free of many reflectors.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2335-2339
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• 2003

To prevent the critical situation due to the fault in the aircraft sensor system, the fault tolerant system with triple or quadruple redundancy can be made. However, if the faults are occurred in two or more than sensors simultaneously, the conventional fault detection process, such as cross-channel monitoring, may give the wrong fault alarm. For this case, we can detect the fault by estimating the state vector based on the system dynamics model, which is nonlinear for aircraft. In this paper, we propose the unscented Kalman filter to estimate the nonlinear state vector. This filter utilizes the so-called unscented transformation of sigma points featured the statistical characteristics of the random variable. For verification, we perform the simulations for F-16 aircraft with accelerometers, gyros, GPS and air data system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.27-32
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• 2008

The laminated composite materials have been applied to various mechanical structures due to their high performance to weight ratios. In this study, we suggest a stochastic finite element scheme for the probabilistic analysis of the composite laminated plates. The composite materials consist of two different materials which constitute the matrix and fiber. The material properties in the major and minor directions are determined depending on the volume fraction of these two materials. In this study, the elastic modulus and shear modulus are considered as random and the effect of these random properties on the behavior of the composite plate is investigated. We adopt the weighted integral scheme in the formulation, which has been recognized as the most accurate method in the statistical methodologies. For verification of the proposed scheme, Monte Carlo analysis is also performed for the comparison with the proposed scheme.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.1
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• pp.155-166
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• 2015

Based on marketing theories of brand and corporate association, and the social psychological theory of identity, the effects of the corporate brand on individual brand loyalty were established via two major routes. The empirical study is based on the response of 330 subjects who participated in a field survey. In the statistical analysis, Correlation Analysis, Factor Analysis, Sequential Equation Model Analysis were used for verification. The corporate association affected the formation of individual brand loyalty both the product level and corporate level. Specifically, the two types of brand response did differ in terms of their strength on brand loyalty. The present study contributes to the academic literature in that it disentangles the construct of the corporate brand from that of the individual brand and investigates the structural relations between the two.

• Journal of Korean Society for Quality Management
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• v.18 no.2
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• pp.117-126
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• 1990

The Purpose of this study is to grasp the general effects of measurement-related investment by industrial firms. We presupposed the hypothesis that the measurement-related investment affects the decrease of product inferiority rates and analyzed the investigation results by means of PIMS(Profit Improvement of Market Strategy) model. As the results, we found out that the firms with positive measurement-related investment showed for less inferiority rates of products considerably. This study put an emphasis on the verification results showing that the considerable increase of measurement-related investment decreases the product inferiority rate by the statistical methods.