• 지식경영연구
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• 제15권1호
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• pp.45-63
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• 2014

Due to advance in Internet technology, most tourists tend to search travel information in the Online Travel Communities(OTC). Given this new paradigm in terms of finding travel information, most of relevant studies in this area are still dealt with explaining tourists' behaviors regardless of the types of communications. Therefore, to overcome some limitations in previous studies, we attempt to examine the relationships between both formal and informal communications and tourists' behavioral changes in the OTC context. Specifically, we developed a research model by employing the PPM(push-pull-mooring) framework and tested it to understand why and how tourists' behaviors might be changed. Survey data collected from 323 online tourists were used to test the model the model using SEM(structural equation modeling). The implications of our empirical findings for both research and practice are discussed.

• Korean Journal of Geomatics
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• 제4권1호
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• pp.23-30
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• 2004

This study aims to establish interior orientation for various types of sensors including frame cameras, panoramic cameras, line cameras, and whisk-broom scanners. To do so, this study suggests the classification of components of interior orientation of which elements are different according to the sensors. This is entailed by incorporation of sensor characteristics into mathematical models of interior orientation parameters are suggested for being used as guidelines in recovering systematic distortions. Finally, the potential errors resulted from the assumption of regarding sensor model of whisk-broom scanner model as that of push-broom scanner are discussed.

• 한국컴퓨터정보학회논문지
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• 제20권8호
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• pp.85-92
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• 2015

Due to the advancements in the capabilities of smart devices and home networks, we are able to easily access multimedia contents stored in a home server. In this paper, we present a wireless media content sharing mechanism for home networks that utilizes UPnP-based DLNA technology. We also present a novel Peer-to-Peer content sharing system that is able to operate on the client as well as server. Our system supports multiple push/pull services simultaneously via a multi-thread technique, and our intuitive user interface facilitates ease of use. Future studies would explore the feasibility of implementing our system in a multi-hop environment or providing a community-wide service.

• 품질경영학회지
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• 제46권2호
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• pp.225-242
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• 2018

Purpose: Recent trends have shown that the usage of big data analysis is becoming the core of identifying promising future technologies and emerging technologies. Accordingly, applying these trends by analyzing defense related data in such sources as journals, articles, and news will provide crucial clues in predicting and identifying core future technologies that can be used to develop creative and unprecedented future weapon systems that could change the warfare. Methods: To identify technology fields that are closely related to the 4th industrial revolution and recent technology development trends, environmental analysis, text mining, and military applicability survey have been included in the process. After the identification of core technologies that are militarily applicable, future weapon systems based on these technologies as well as their operation concepts are suggested. Results: Through the study, 73 important trends, from which 11 mega trends are derived, are identified. These mega trends can be expressed by 13 promising technology fields. From these technology fields, 248 promising future technologies are identified. Afterwards, further assessment is performed, which leads to the selection of 63 core technologies from the pool. These are named as "future defense technologies" which then become the bases for 40 future weapons systems that the military can use. Conclusion: Predicting future technologies using text mining analysis have been attempted by various organizations across the globe, especially in the fields related to the 4th industrial revolution. However, the application of it in the field of defense industry is unprecedented. Therefore, this study is meaningful in that it not only enables the military personnel to see promising future technologies that can be utilized for future weapon system development, but helps one to predict the future defense technologies using the method introduced in the paper.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.197-200
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• 1998

Three switched-capacitor(SC) networks are presented including series-parallel capacitor set, reversed-switched-capacitor network and push-pull switched-capacitor network, the performances of which are discussed. Combining the SC networks with traditional DC-DC converters, we form several new topologies. Experiment and analyzed results show that the behavior of a DC-DC converter with large voltage ratio can be improved. A wider voltage conversion range is also obtained.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.148-149
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• 2010

본 논문에서는 친환경 차량용 보조배터리 충 방전을 위한 3상 양방향 DC-DC컨버터를 제안한다. 제안한 컨버터는 클램프 스위치의 동작으로 전압 및 전류공진을 최소화하고 대전류단의 순환전류를 감소시켜 전류정격을 줄였다. 제안하는 컨버터의 이론적 해석과 시뮬레이션을 통해 타당성을 검증하였다.

• 융합보안논문지
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• 제15권7호
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• pp.111-118
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• 2015

급변하는 사회의 변화로 말미암아 강력 범죄가 급격하게 증가하고 있다. 하지만 이에 대한 경찰 인력의 부족, 현장출동을 하더라도 범죄 상황에 대한 파악 등을 위한 시간 지연 등의 문제가 심각하다. 이미 오래전부터 관련 연구자들이 이를 해결하고자 많은 연구방법들을 제안하였다. 하지만 현실적으로 기존에 제안된 연구방법들이 아직도 부족한 점이 많다. 그러므로 본 연구에서는 스마트폰과 초고속 인터넷서비스 기술을 활용해서 범죄 상황에 대한 신속한 파악과 푸쉬 서비스를 사용해서 보안 서비스를 제공하고자 한다. 제안한 시스템은 스마트폰 사용자가 사전에 설정한 단축키를 누르면 주변에서 발생하는 음성 정보를 실시간으로 녹음하고, 저장된 음성 정보와 LBS 정보를 인증 과정을 거쳐 서버에 저장한다. 그리고 서버는 저장된 음성 정보와 LBS 정보를 푸쉬 서비스를 사용해서 가족들에게 알린다. 현재까지 우리는 제안시스템에 설계를 마쳤다. 그리고 스마트폰 사용자 앱과 인증 서버를 구현했다. 그리고 인증 서버에서 푸쉬 서비스를 사용해서 사용자 가족에게 메시지를 전달해서 알릴 수 있는 상태이다. 하지만 향후 연구를 통해 좀 더 제안한 연구가 타당성을 검토해야만 한다.

• 한국공간구조학회논문집
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• 제19권4호
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• pp.45-52
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• 2019

The purpose of the paper is to introduce a system that reduces the occurrence of weak-story in the event of earthquake. Weak-story concentrates deformation on the story and causes all member to collapse before the capacity of all member is reached. This paper introduces Strong-Back system (SB) to protect weak story. SB is a hybrid of zipper frame, tied eccentrically braced frame, and elastic truss system and it is divided into elastic and inelastic areas. Elastic areas prevent the generation of weak story by distributing energy, and inelastic areas dissipate energy through buckling or yielding. In this paper, the seismic performance is evaluated by comparing the four type braced frame with SB through push-over analysis. The four criteria are compared from the base shear, the ductility capacity, the column failure order, and the quantity of brace. As a result, SB proved to have sufficient performance to protect the weak-story.

• Earthquakes and Structures
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• 제12권5호
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• pp.529-541
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• 2017

According to the definition, progressive collapse could occur due to the initial partial failure of the structural members which by spreading to the adjacent members, could result in partial or overall collapse of the structure. Up to now, most researchers have investigated the progressive collapse due to explosion, fire or impact loads. But new research has shown that the seismic load could also be a factor for initiation of the progressive collapse. In this research, the progressive collapse capacity for the 5 and 15-story steel special moment resisting frames using push-down nonlinear static analysis, and nonlinear dynamic analysis under the gravity loads specified in the GSA Guidelines, were studied. After identifying the critical members, in order to investigate the seismic progressive collapse, the 5-story steel special moment resisting frame was analyzed by the nonlinear time history analysis under the effect of earthquakes with different characteristics. In order to account for the initial damage, one of the critical columns was weakened at the initiation of the earthquake or its Peak Ground Acceleration (PGA). The results of progressive collapse analyses showed that the potential of progressive collapse is considerably dependent upon location of the removed column and the number of stories, also the results of seismic progressive collapse showed that the dynamic response of column removal under the seismic load is completely dependent on earthquake characteristics like Arias intensity, PGA and earthquake frequency contents.

• Steel and Composite Structures
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• 제23권1호
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• pp.67-85
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• 2017

This study investigates numerically the behavior of tilted angle shear connectors embedded in solid concrete slabs. Two different tilted angle connectors were used, titled angle with 112.5 and 135 degrees between the angle leg and steel beam flange. A nonlinear finite element model was developed to simulate and validate the experimental push-out tests. Parametric studies were performed to investigate the variations in concrete strength and connector's dimensions. The results indicate that the ultimate strength of a tilted angle shear connector is directly related to the square root of the concrete compressive strength. The effects of variations in the geometry of tilted angle connectors on the shear capacity are discussed in details. Based on the numerical analyses, two equations are proposed to estimate the ultimate capacity of tilted angle shear connectors of 112.5 and 135 degrees in the defined range of parameters.