• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.545-552
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• 2001

Analysis of a structure for vertical vibration requires a lot of computational efforts because large number of degrees of freedom are generally involved in the dynamic response. Especially, when a structure is loaded with local vibration source, it may not be economical to model the whole structure to obtain the responses of specific members located near or far from the sources. In this study, substructure models have been used for analysis of local vibration An analysis of local vibration is performed for the case that the loaded point and the response point are located on the same floor. Other analysis is performed for the case that the loaded point and the response point are located on the different floor. In this case, if only the floors on which loaded and response points are located are modeled, response of substructure model is very different from that of full model. So, there should be a consideration that degrees of freedom of floors in addition to those of loaded and response floors are included to improve results of dynamic analysis. In this study, floors between loaded floor and response floor were modeled so that modeshapes which affect the response are presented well.

• 전기학회논문지
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• 제58권2호
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• pp.292-300
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• 2009

This paper presents an LED BLU driving circuit with a local-dimming structure. The efficiency of the proposed LED driver has been improved by parallel driving 8 serial-connected LED arrays. It employed the soft-switching boost converter topology to reduce the switching power loss of the hard switching boost converter. Soft- and hard-switching converters have the same structure except that the free-wheeling diode in the hard-switching converter is replaced with the n-channel MOSFET in the soft-switching one. The proposed boost converter was compared with the hard switching converter. The soft-switching converter reveals superior ripple and efficiency. A smaller inductance can be used for the soft-switching converter contrasting to the hard-switching one. We also studied on an over-voltage protection circuit of the output of the driver at the no load condition. The protection circuit was applied to the proposed driver, and its operation was confirmed by experiment. Using a local-dimming technique, power consumption of LCD BLUs can be reduced as low as possible according to the brightness of its image.

• 아태비즈니스연구
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• 제13권1호
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• pp.277-288
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• 2022

Purpose - This study analyzed the determinants of local unemployment rate in Korea using panel data from 16 metropolitan cities and provinces from 2000 to 2018. Design/methodology/approach - We use a dynamic spatial panel model that considers characteristics of the regional unemployment rate such as the common factors effect, spatial dependence, and serial correlations. Findings - The local unemployment rate is affected by the past and present values of the national unemployment rate. And it is significantly affected by the past local unemployment rate and the past neighboring unemployment rate because spatial dependence and serial correlations are clearly present. In addition, when the industrial structure diversity and labor productivity were high, the regional unemployment rate decreased, and when the education level was high, the regional unemployment rate increased. Research implications or Originality - In order to reduce regional unemployment rate, it is necessary to plan and establish regional customized industrial structure policies under the stance of diversification rather than specializing the regional industrial structure and accompany improvement of the quality of education with the number of years of education. In addition, the redistribution of labor from low labor productivity sectors to high labor productivity sectors through technology development will help to reduce the local unemployment rate.

• 한국농촌건축학회논문집
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• 제24권4호
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• pp.41-48
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• 2022

The purpose of this study is to present the implications of the rural living area setting and rural spatial structure analysis of the rural spatial strategy plan through case analysis. Following the decentralization of autonomy and the promotion of the transfer of state affairs to local areas, some of the general agricultural and fishing village development projects of the Ministry of Agriculture, Food and Rural Affairs were transferred to local areas. In addition, in 2020, the Ministry of Agriculture, Food and Rural Affairs introduced a rural agreement system for 113 cities and counties. However, since the understanding of the field is still low, this study attempted to present implications through a case analysis of the structure of rural space and the establishment of rural living areas in three local governments in Chungcheong. As a result of the study, in the stage of establishing the living zone, it is necessary to comprehensively review the contents reviewed in the analysis of the current status and conditions. However, the two local governments had insufficient interpretation of the axis by function and the establishment of the base area, or were using the upper plan as it was. Second, the source of the data used in the survey on the distribution status of living SOC facilities is unclear. Since the distribution status of living SOC facilities overlaps with accessibility analysis, OD data analysis, and resident survey results and is used as the basis for setting living areas, the data source should be clearly marked, and verification should be possible. Third, amenity (facility) resources were classified and analyzed according to the conditions and characteristics of local governments. The local government that applied the guidelines as they were was A local government, and the remaining local governments conducted surveys and analysis according to the current status. Forth, since the establishment of the rural living area is the minimum unit supported by government policies through future rural agreements, it is necessary to distinguish them based on quantitative standards in the process of establishing them. Only one case area presented clear grounds and standards, and the rest of the case areas presented standards but are based on non-quantitative standards. In order for rural agreements to be sustainable in the future and benefit local residents, it is necessary to use or establish a government-level institution that can collect and produce objective data. In addition, it is necessary to find ways to specify and standardize the standards for setting the living area and specify them in the guidelines.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.363-372
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• 2017

This paper presents a novel face recognition algorithm based on the deep convolution neural network and key point detection jointed local binary pattern methodology to enhance the accuracy of face recognition. We firstly propose the modified face key feature point location detection method to enhance the traditional localization algorithm to better pre-process the original face images. We put forward the grey information and the color information with combination of a composite model of local information. Then, we optimize the multi-layer network structure deep learning algorithm using the Fisher criterion as reference to adjust the network structure more accurately. Furthermore, we modify the local binary pattern texture description operator and combine it with the neural network to overcome drawbacks that deep neural network could not learn to face image and the local characteristics. Simulation results demonstrate that the proposed algorithm obtains stronger robustness and feasibility compared with the other state-of-the-art algorithms. The proposed algorithm also provides the novel paradigm for the application of deep learning in the field of face recognition which sets the milestone for further research.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권1호
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• pp.1-20
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• 2013

In the present paper, the sloshing resistance performance of a huge-size LNG carrier's insulation system is evaluated by the fluid-structure interaction (FSI) analysis. To do this, the global-local analysis which is based on the arbitrary Lagrangian-Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG sloshing of a KC-1 type LNG carrier insulation system. During the global analysis, the sloshing flow and hydrodynamic pressure of internal LNG are analyzed by postulating the flexible insulation system as a rigid body. In addition, during the local analysis, the local hydroelastic response of the LNG carrier insulation system is computed by solving the local hydroelastic model where the entire and flexible insulation system is adopted and the numerical analysis results of the global analysis such as initial and boundary conditions are implemented into the local finite element model. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.

• Smart Structures and Systems
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• 제33권3호
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• pp.201-215
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• 2024

Spline chirplet transform and local maximum synchrosqueezing are introduced to present a novel structural instantaneous frequency (IF) identification method named local maximum synchrosqueezing spline chirplet transform (LMSSSCT). Namely spline chirplet transform (SCT), a transform is firstly introduced based on classic chirplet transform and spline interpolated kernel function. Applying SCT in association with local maximum synchrosqueezing, the LMSSSCT is then proposed. The index of accuracy and Rényi entropy show that LMSSSCT outperforms the other time-frequency analysis (TFA) methods in processing analytical signals, especially in the presence of noise. Numerical examples of a Duffing nonlinear system with single degree of freedom and a two-layer shear frame structure with time-varying stiffness are used to verify the effectiveness of structural IF identification. Moreover, a nonlinear supported beam structure test is conducted and the LMSSSCT is utilized for structural IF identification. Numerical simulation and experimental results demonstrate that the presented LMSSSCT can effectively identify the IFs of nonlinear structures and time-varying structures with good accuracy and stability.

• 수산해양기술연구
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• 제33권4호
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• pp.334-345
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• 1997

Reliability-based design approaches are needed for cylindrical shell structure whose design and operational experiences are few and which are subjected to external loads of random loads. In designing new type of structure, it is very difficult to evaluate the safety factors due to lack of previous design data and operational experience. To solve the above mentioned problem, much attention is being focussed on rational reliability based design approaches. This paper deals with weight-optional reliability-based design of cylindrical shell structure subjected to structural reliability constraints taking into account of the effect of local buckling and interactive behavior between local and global buckling. Present mentioned is compared with the exiting optional design method based only on safety factors. Numerical simulation reveals that the present method leads to lighter structure (4% reduction in weight compared to the existing optimal design) with the same reliability index. For larger structures with more number of structural members and possible failure modes, the present W0RBD procedure will be an efficient tool in designing cost-effective rationalized economic design.

• Smart Structures and Systems
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• 제23권4호
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• pp.393-403
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• 2019

Applying more features gives us better accuracy in modeling; however, increasing the inputs causes the curse of dimensions. In this paper, a new structure has been proposed for fault detecting and identifying (FDI) of high-dimensional systems. This structure consist of two structure. The first part includes Auto-Encoders (AE) as Deep Neural Networks (DNNs) to produce feature engineering process and summarize the features. The second part consists of the Local Model Networks (LMNs) with LOcally LInear MOdel Tree (LOLIMOT) algorithm to model outputs (multiple models). The fault detection is based on these multiple models. Hence the residuals generated by comparing the system output and multiple models have been used to alarm the faults. To show the effectiveness of the proposed structure, it is tested on single-shaft industrial gas turbine prototype model. Finally, a brief comparison between the simulated results and several related works is presented and the well performance of the proposed structure has been illustrated.

• 한국인구학
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• 제21권2호
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• pp.37-57
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• 1998

이 논문은 통계청의 연구비지원으로 수행한 연구인 ‘여성인구의 특성 및 변화’의 일부로서, 인구학회와 통계청이 공동으로 개최한 <인구변화와 한국사회의 미래변화에 대한 세미나>에서 발표한 논문을 수정한 것이다. 여성의 인구구조는 지역간의 인구이동에도 불구하고 지역별로 상당히 다르고, 여성의 경제활동상태와 취업구조 또한 지역별 산업구조의 차이로 인해서 지역간에 상당한 차이를 보인다. 그럼에도 불구하고 지금까지 지역별 여성의 인구구조와 취업구조의 차이에 대한 연구가 거의 이루어지지 않고, 지방정부 또한 지역여성인구에 대한 특성을 제대로 파악하지 못하고 있다. 그 결과 지방정부가 수립${\cdot}$시행하고 있는 여성정책들의 실효성과 효율성은 상당히 낮은 것으로 평가되고 있다. 이에 본 논문은 <인구주택총조사> 2% 표본자료의 기술적인 분석(descriptive analysis)을 통해서, 지역별 여성의 인구구조, 경제활동상태, 취업구조 등에 대한 개괄적인 현황을 파악하고, 향후 지방정부의 여성정책에 대한 기본적인 방향을 제시하였다.