• Communications for Statistical Applications and Methods
• /
• 제30권4호
• /
• pp.369-388
• /
• 2023

In this paper, we develop the two-step procedure that detects and estimates the position of structural changes for multivariate nonstationary time series, either on mean parameters or second-order structures. We first investigate the presence of mean structural change by monitoring data through the aggregated cumulative sum (CUSUM) type statistic, a sequential procedure identifying the likely position of the change point on its trend. If no mean change point is detected, the proposed method proceeds to scan the second-order structural change by modeling the multivariate nonstationary time series with a multivariate locally stationary Wavelet process, allowing the time-localized auto-correlation and cross-dependence. Under this framework, the estimated dynamic spectral matrices derived from the local wavelet periodogram capture the time-evolving scale-specific auto- and cross-dependence features of data. We then monitor the change point from the lower-dimensional approximated space of the spectral matrices over time by applying the dynamic principal component analysis. Different from existing methods requiring prior information on the type of changes between mean and covariance structures as an input for the implementation, the proposed algorithm provides the output indicating the type of change and the estimated location of its occurrence. The performance of the proposed method is demonstrated in simulations and the analysis of two real finance datasets.

• Journal of Korea Trade
• /
• 제27권5호
• /
• pp.23-40
• /
• 2023

Purpose - This study aims to present the changes and directions in the automotive supply chain in the face of changes in the global supply chain caused by external factors and the integration of industries resulting from internal factors. Assuming FDI in the Korean automotive industry in the US, this study analyzed the influential factors over the long term and derived the optimal location. Design/methodology - For this analysis, the characteristics and current status of the automotive industry are presented. Additionally, the study emphasizes the necessity and direction of change. The factors influencing Korea-US FDI in the automotive industry and the electric vehicle industry were analyzed through panel analysis. The optimal location from the perspective of distribution costs was selected using linear programming under the assumption that local demand will be replaced by local production in the future. Findings - This study found that the electric vehicle supply chain will change with the characteristics of the electric and electronic industries rather than with the traditional automotive industry. Additionally, in deriving the optimal location, the study emphasized the proximity to the consumption market. Originality/value - The analysis method and conclusions of this study not only present the influential factors and direction of FDI in the automotive industry but also can be applied to other industries. Moreover, the study provides practical and policy implications for industries and governments considering FDI in the US.

• 한국콘텐츠학회논문지
• /
• 제18권1호
• /
• pp.258-267
• /
• 2018

이 연구는 한국에서는 논의 된 적 없는 스웨덴의 알메달렌 사례를 중심으로 지역축제가 지역 경제 활성화에 기여하였는지에 대해 실증적 관점에서 연구하고자 하였다. 이를 위해 알메달렌 개최 기간 동안 고틀란드의 사회 문화적 측면과 경제적 측면을 3단계로 분석하고 평가함으로써 향후 한국에서의 알메달렌 벤치마킹에 정책적 시사점을 도출하고자 하였다. 스웨덴 알메달렌의 경제적 효과를 3단계에 걸쳐 분석한 결과, 1단계 자원조사분석에서는 고틀란드의 아름다운 자연경관을 바탕으로 관광객 유치에 긍정적인 효과가 있는 것으로 나타났다. 2단계 운영평가에서는 지역경제 활성화와 관련한 평가지표로서 인구의 증가 및 안정에 대해 살펴본 결과, 고틀란드는 꾸준히 새로운 인구의 유입과 다양한 일자리가 창출됨으로써 지역 소득이 증대되는 것을 확인 할 수 있다. 마지막 3단계 지역이미지 제고에서는, 각계각층의 다양한 구성원이 고틀란드 축제에 참가함으로써 외부와의 소통이 유연해지고, 사회참여 기회가 증가함으로써 지역 이미지에 긍정적인 영향을 미치는 것으로 나타났다. 이러한 연구결과를 바탕으로 스웨덴 지역축제인 알메달렌을 벤치마킹하기 위한 정책적 시사점은 다음과 같다. 첫째, 다양한 사람들의 참여를 유도하기 위한 적합한 장소의 선정이 필요하다. 둘째, 특정 기관 중심의 일방적 정보 제공이 아닌 의견을 주고 받을 수 있는 소통의 장이 될 수 있도록 해야 한다. 셋째, 비영리를 목적으로 진행하면서 지역 이미지를 긍정적으로 변화 시킬 수 있는 노력이 필요하다.

• 산업융합연구
• /
• 제21권11호
• /
• pp.135-145
• /
• 2023

본 연구의 목적은 숲 체험 프로그램이 지역아동의 폐활량, 건강체력, 정서지능, 심리적 안녕감에 미치는 효과를 규명하는 것입니다. 본 연구는 D시 지역아동센터에 2022년 7월 10일부터 9월 30일까지 12주간 초등 3, 4학년을 대상으로 진행되었으며, 실험군과 대조군의 폐활량, 건강체력, 정서지능, 심리적 안녕감의 변화를 t-test를 이용하여 분석하고 검증하였다. 폐활량과 건강체력의 변화는 폐활량에서 대조군과 실험군 간에 통계적으로 유의한 차이가 있었으며(t=24.56, p<.05), 건강체력의 요소 중 심폐지구력에서도 두 집단 간에 통계적으로 유의한 차이가 있었습니다(t=16.64, p<.05). 정서지능과 심리적 안녕감의 변화는 정서지능(t=2.31, p<.05)과 심리적 안녕감(t=3.21, p<.05)에서 실험군과 대조군 간에 통계적으로 유의한 차이가 있었습니다. 본 연구를 통해 숲 체험 프로그램의 긍정적인 효과를 확인하였고 지역의 특성에 맞게 숲 체험 교육 공간의 확충과 맞춤형 숲 체험 프로그램의 개발로 아동들의 참여 여건이 개선되어 많은 아동들이 경험할 수 있도록 제도적 장치가 필요하다고 사료된다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 추계학술대회 논문집
• /
• pp.271-272
• /
• 2008

This paper is concerned with the prediction of micro structural changes of pearlitic steel wire during clod drawing. The most important microstructural aspects are ferrite/cementite interlamellar spacing, cementite shape and thickness, since those are crucial factors to determine the mechanical strength of pearlitic steel. In this study, a couple of new algorithms to predict the above microstructural changes are developed based on the deformation histories of macro material points obtained from finite element simulations for pearlitic steel wire drawing. Some predictions are shown. The special features of the algorithms developed in this study are discussed in details.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제18권1호
• /
• pp.1-5
• /
• 2013

Global climate changes affect the local hydrologic cycle, and subsequently, require changes in water resource management strategies of Korea. Variations in precipitation and urbanization have adverse effects on the reasonable and efficient utilization of groundwater resources. Groundwater management strategies of Korea have been implemented based on the evaluation of "sustainable yield", which is calculated from the amount of annual recharge. However, this sustainable yield has no consideration of natural discharge and dynamic equilibrium of the groundwater system. Therefore, for the effective groundwater management strategies of the following decades, we need representative and reliable observations, and have to develop methods for the systematic analysis and interpretations of the data to draw valid information in linkage of natural and societal environmental changes.

• Architectural research
• /
• 제22권1호
• /
• pp.1-11
• /
• 2020

From 1990s to the present, in China, residential communities has developed rapidly in terms of government policies and living environments. With economic development, dwelling commercialization and socialization gradually reshaped the housing distribution system and local government management in Chinese urban area. After this process, dwellings were endowed with commodity attributes, which were planned and designed depending on residents' requirements of life. During the 30 years of social transformation, Chinese citizens' lifestyle also had huge changes. In this period, the forms of residential area improved constantly to keep pace with social development. This study aims to research the features of contemporary communities and survey citizens' lifestyle changes to find the reasons of the evolution of communities. Moreover, in this paper, there is a clear explanation of the reasons why gated communities are popular in Chinese urban area. In addition, comprehensive data analysis is derived from a questionnaire administered in Shanghai, China. In this part, the questionnaire surveys what factors about lifestyle influence the transformation of living environments and residential buildings. The results of survey show that residents have housing preferences dependent on their lifestyles, and their daily needs related with environmental features.

• 한국주거학회논문집
• /
• 제17권5호
• /
• pp.67-76
• /
• 2006

The purpose of this study was to explore the periodic changes of apartment supply between 1980 and 2001 in the City of Donghae. A survey was conducted with 82 apartment complexes that were built in during 21years. The data were itemized and specified by the unit house area, story, periodic and local apartment distribution. They were classified by five:(5) periods and analyzed by each apartment complexes for building characteristics. There were found that apartment housing were influenced by many primary factors such as demographics and a lot of the housing politics etc. The results of this study were as follows: 1) Apartment supply in the City of Donghae mass-produced from 1980 to 2001; Especially the forth period was supplied 5,999 households. 2) Between south area and north area was found a regional disparity. 3) The exclusive use $34{\sim}66m^{2}$ were continuously and centrally supplied according to the housing policy and practical demand. 4) For the types of story were variously found ; Especially the below 5 story apartment was continuously supplied.

• 농촌지도와개발
• /
• 제4권2호
• /
• pp.415-421
• /
• 1997

The objectives of this study were 1) to evaluate the first year of localization of agricultural extension in Korea, 2) to present the development directions and implications of agricultural extension service in the next year of localization. The major results and implications were as follows. 1. The positive changes in localization were to establish local special projects and to work in agricultural extension without personnel changes. 2. The negative changes in localization were increase of unnecessary work load and decrease of morale because of lowered status. 3. The development directions were to cut back unnecessary work load, to rearrange an office, and to return to the national status of extension personnels.

• 정보학연구
• /
• 제12권4호
• /
• pp.25-32
• /
• 2009

Iris recognition is a biometric technology which can identify a person using the iris pattern. It is important for the iris recognition system to extract the feature which is invariant to changes in iris patterns. Those changes can be occurred by the influence of lights, changes in the size of the pupil, and head tilting. This paper is appropriate for the embedded environment using local gradient histogram embedded system using iris feature extraction methods have implement. The proposed method enables high-speed feature extraction and feature comparison because it requires no additional processing to obtain the rotation invariance, and shows comparable performance to the well-known previous methods.