• Tribology and Lubricants
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• 제36권4호
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• pp.215-231
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• 2020

The paper presents extensive survey and review of experimental and analytical researches on fluid film bearings and squeeze film dampers (SFDs) for turbomachinery available in open literature (major archival international journals) published recently (2018 and 2019 only). Over 60 published research works are reviewed based on the research topics and objectives, the types of bearings, size of bearings, and main design parameters with a brief summary of experiments and/or predictions in each work. Some important findings and general observations about the experimental and/or predictive data are also presented. There are several major trends observed throughout the survey. A large portion of the papers focuses on bearing surface textures and effect of operating and assembly conditions on static and/or dynamic forced performances, as well as bearing surface roughness and wear patterns. Researches on geometry of orifices and recesses in hydrostatic (or hybrid) bearings, as well as bearing system stability predictions using thermohydrodynamic analysis and computational fluid dynamics (CFD), are considered as significant topics. Studies on SFDs mainly focus on experimental identification of force coefficients for various SFD geometries and sealing conditions. Reliable experiments of fluid film bearings and SFDs along with the development of experimentally benchmarked predictive tools enable reinforcement of the path for reliable implementations of the bearing components into high performance rotating machinery operating at extreme and harsh conditions. The extensive list of sources of recent experiments in the available open literature is a welcome addition to the analytical community to gauge the accuracy of predictive tools.

• Structural Engineering and Mechanics
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• 제90권4호
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• pp.417-428
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• 2024

Nanocomposite-reinforced concrete systems have gained increasing attention in bridge construction due to their enhanced mechanical properties and durability. Understanding the transient dynamics of these advanced materials is crucial for ensuring the structural integrity and performance of bridge infrastructure under dynamic loading conditions. This paper presents a comprehensive study of the measurement techniques employed for assessing the transient dynamics of nanocompositereinforced concrete systems in bridge construction applications. A numerical method, including modal analysis are discussed in detail, highlighting their advantages, limitations, and applications. Additionally, recent advancements in sensor technologies, data acquisition systems, and signal processing techniques for capturing and analyzing transient responses are explored. The paper also addresses challenges and opportunities in the measurement of transient dynamics, such as the characterization of nanocomposite-reinforced concrete materials, the development of accurate numerical models, and the integration of advanced sensing technologies into bridge monitoring systems. Through a critical review of existing literature and case studies, this paper aims to provide insights into best practices and future directions for the measurement of transient dynamics in nanocompositereinforced concrete systems, ultimately contributing to the design, construction, and maintenance of resilient and sustainable bridge infrastructure.

• 한국항해항만학회지
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• 제40권2호
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• pp.67-72
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• 2016

Vietnam's sea-port industry has experienced a significant development in recent years. Especially in Northern Vietnam, both the demand and supply of handling services for containerized cargoes have increased at a considerable rates. Accompany with such movement, the competition among container terminals in the area becomes fiercer. In this paper, Hierarchical Cluster Analysis is employed to classify all 11 container terminals in Northern Vietnam by collecting data concerning terminal competitiveness. After the classification, each group will be discussed in order to reveal more details about their competitive characteristics. The paper consists of five sections. Section 1 is the general introduction. Section 2 provides a general literature review about competitiveness and factors to evaluate competitiveness. Section 3 explains variables and methodology applied to do the analysis. Section 4 presents the results with linkage to the current condition. Section 5 summarizes the analysis results. It is shown that container terminals in Northern Vietnam should not only pay attention to their service qualities but also have to find out an appropriate mechanism to avoid unhealthy competition. The paper is expected to contribute a background for further researches in container terminals' competition in the region as well as hints for operators in planning and making decisions.

• Computers and Concrete
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• 제33권4호
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• pp.425-443
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• 2024

Floods are among the most common natural hazards in urban areas. To mitigate the problems caused by flooding, unstructured data such as images and videos collected from closed circuit televisions (CCTVs) or unmanned aerial vehicles (UAVs) have been examined for flood management (FM). Many computer vision (CV) techniques have been widely adopted to analyze imagery data. Although some papers have reviewed recent CV approaches that utilize UAV images or remote sensing data, less effort has been devoted to studies that have focused on CCTV data. In addition, few studies have distinguished between the main research objectives of CV techniques (e.g., flood depth and flooded area) for a comprehensive understanding of the current status and trends of CV applications for each FM research topic. Thus, this paper provides a comprehensive review of the literature that proposes CV techniques for aspects of FM using ground camera (e.g., CCTV) data. Research topics are classified into four categories: flood depth, flood detection, flooded area, and surface water velocity. These application areas are subdivided into three types: urban, river and stream, and experimental. The adopted CV techniques are summarized for each research topic and application area. The primary goal of this review is to provide guidance for researchers who plan to design a CV model for specific purposes such as flood-depth estimation. Researchers should be able to draw on this review to construct an appropriate CV model for any FM purpose.

• 응용통계연구
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• 제29권6호
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• pp.1041-1059
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• 2016

학술 연구나 정책 입안 등을 위한 심층적 자료 활용의 확대는 동시에 개별 정보 노출에 대한 염려도 증가시킨다. 때문에 최근 이십여 년 간 통계적 노출제어(정보보호) 분야에서 많은 논문들이 발표되었다. 본 논문은 그러한 연구 내용들을 정리하여 국내 통계인들과 기관들에게 소개하고자 한다. 주요 내용으로 국소통합이나 잡음추가와 같은 전통적인 매스킹 기법 뿐만 아니라, 온라인 자료 분석 시스템에서의 정보보호 처리, 차등정보보호를 통한 노출제어 및 재현자료를 활용한 정보보호 대안 모색에 대해 다룬다. 또한 각각의 주제에 대한 방법론 소개와 함께 활용 사례 및 장단점을 논의하였다. 본 논문이 실제적인 통계적 노출제어 문제를 고민하는 통계인들에게 도움이 되기를 바란다.

• Asia pacific journal of information systems
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• 제24권4호
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• pp.577-610
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• 2014

Although service innovation is not a new concept, innovation research in general tends to focus on technological innovation by manufacturing firms. With this view, innovation studies focus on product(e.g., goods) and process(e.g., product systems) innovation, ignoring service innovation and its inherent opportunities. Since major economy has been transformed to service economy, service innovation is considered a new effective way to sustain and gain a competitive advantage. Service innovation is no longer regarded merely as a side activity to product innovation; it has become a main research topic in its own right, accompanied by an increasing focus on services. While the number of service innovation studies has increased dramatically in the past 30 years in international research, few studies have been performed in domestic studies because domestic service innovation research began from the middle of 2000. In addition, there are no comprehensive literature reviews describing the evolution of service innovation research in both international and domestic studies because of the heterogeneities of service industry and multidiscipline characteristics of service innovation studies. To bridge this research gap, the purpose of this paper is to perform an extensive literature review and synthesis to enable a critical review of extant research on service innovation and trace its evolution, which will establish a foundation for further studies. By reviewing 169 articles (136 international papers; 33 domestic papers) published between 2000 and 2014 (in past 15 years), primarily in leading service, innovation and management information systems journals, this study analyzes the progression of service innovation research according to the four aspects such as number of studies, topics, methodologies and target industries. Overall, the view of service innovation has evolved, from a complement of traditional product innovation to a multidimensional, all-encompassing concept that entails several functions, both within and outside the firms. The results showed that domestic research still stays at the formation phase of service innovation studies although international research is in the maturity or multidimensional phase. We found increasing recent activities pertaining to service innovation, resulting from the increasing interest in services innovation across various industries and the links of new topics to the service innovation concept in both international and domestic studies. However, the main focus of service innovation research showed a different propensity between international and domestic studies: the former mainly focuses on a much more diversified pattern, emphasizing the linkages between service innovation and business strategy while the latter mainly focuses on the service innovation process(system) and service design. In addition, there are many case studies in domestic studies while many empirical studies in international studies. Domestic studies should increases the understanding of the interplay between service innovation and product innovation within manufacturing firms. Furthermore, rather than focusing on intrinsic distinctions between service innovation and product innovation, researchers should strive to develop and conceptualize service innovation in domestics studies. The present research also provides useful implications for practitioners. First, this study contributes to expand the current understanding of service innovation research by performing an extensive literature review. Second, tracing and comparing the progression and trends of service innovation research between international and domestic studies, this study showed the similarities and differences between them, which provide practical guidance on future research directions and research agenda. Third, this study performed literature review establishing the analysis system in the initial stage and using them to analyze articles, which is leading to explain the research review of service innovation more systematically and objectively. Finally, this study suggests the domestic researchers their future interests and topics of service innovation research.

• 터널과지하공간
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• 제30권1호
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• pp.29-38
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• 2020

본 연구에서는 최근 10여 년 간 북한 광업 및 암반공학 분야의 발전 동향 및 최신 연구현황을 파악하기 위해, 2008-2017년 기간 출판된 북한 내 광업 관련 주요 학술지인 '채굴공학', '지질 및 지리과학', '기술혁신'을 대상으로 광업 및 암반공학 분야 연구논문의 투고 현황 및 연구 방법론을 분석하였다. 먼저 각 학술지에 수록된 연구논문의 서지정보 및 초록 자료를 정리하여 기초자료 데이터베이스를 작성하였다. 그리고 작성한 기초자료 데이터베이스를 활용하여 연구 분야별 학술지 투고 경향을 분석하였으며, 그 방법론 및 성과가 뛰어나다고 판단되는 연구논문에 대한 추가조사를 수행하여 북한 광업 및 암반공학 분야의 동향을 분석하였다. 연구동향 분석 결과, 최근 북한의 과학기술정책 변동 및 광업환경의 악화에 따른 정량화·자동화 경향성을 확인할 수 있었다. 본 연구결과는 향후 북한 광물자원 개발 전략 수립 및 경제성 평가를 위해 활용 가능할 것으로 판단되며, 향후 남북 기술협력 및 북한 현지 조사를 통해 보완될 수 있을 것이다.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(역학)
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• pp.137-141
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• 1994

The purpose of this paper is to examine what is meant by a ralid measure of health. Guyatt, Kirshner and Jaeschke propose that health tests should be designed so as to have one of several kinds of validity: 'longitudinal construct validity' for those which are used for longitudinal research designs, and 'cross-sectional construct validity' for those which are used for cross-sectional designs. Williams and Naylor argue that this approach to test classification and validation confuses what a test purports to measure with the purpose for which it is used, and that some tests have multiple uses. A review of the meanings of validity in the psychologica test literature shows that both sets of authors use the term validity in an idiosyncratic way. Although the use of a test (evaluated by content validity) should not be conflated with whether the test actually measures a specified construct (evaluated by construct validity);' if health is actually made up of several constructs (as suggested in Hyland's interactional model) then there may be an association between types of construct and types of purpose. Evidence is reviewed that people make several, independent judgements about their health: cognitive perceptions of health problems are likely to be more sensitive to change in a longitudinal research design. whereas emotional evaluations of health provide less bias in cross-sectional designs. Thus. a classification of health measures in terms of the purpose of the test may parallel a classification in terms of what tests purport to measure.

• Journal of Information Technology Applications and Management
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• 제18권3호
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• pp.31-39
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• 2011

The weakening of the traditional cultures is becoming more evident from the final quarter of the last century, a period of time where the world starts to look like a "small village" in all means. A substantial cause of cultural deterioration shows to be the growing use of information and communication technologies widening the views, mentalities, and perspectives of people. Today the adolescent groups frequently owning, utilizing and consequently being charmed by the electronic equipment such like computers, internet and cellular phones have developed a unique tradition/practice in sensing and meaning life triggering larger generation gap and fading of established cultures. The main focusing of the paper is on the correlation between computer and internet use and life satisfaction, level of hope, personal development assessments and expectations of the adolescent groups in Turkey. Interpretation of the survey findings indicates that this group grading highest in use of that shows to be the happiest, most hopeful and optimistic ones among other groups. Methodologically, the study is based on data analysis and a review of recent key literature. For more dependable results a further study comparing similar tendencies of the similar groups of other nationalities is recommended.

• 한국IT서비스학회지
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• 제18권5호
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• pp.99-117
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• 2019

In recent years, the one-person media has increasingly gained popularity. The purpose of this study is to investigate the relationship among the service quality, satisfaction and intention of continuous use of one-person media service and to further examine the mediating effect of satisfaction operating on the relationship between the service quality and intention of continuous use. Based on the literature review, hypotheses were developed and the research model was built for testing. The sample of 358 users was selected to achieve these objectives. From the analysis of PLS(Partial Lease Square Path Analysis), key research findings are summarized as follows. First, relationships among the service quality, satisfaction, and intention of continuous use were all positively correlated each other. Second, the effect of service quality on intention of continuous use was mediated by satisfaction. Third, the content quality of one-person media has the higher effectiveness than platform quality to satisfaction and intention of continuous use. Results of this paper are expected not only to emphasize the importance of satisfaction based on the service quality, but also to provide multifaceted implications and directions for the management of one-person media service effectively.