• 한국정보통신학회논문지
• /
• 제22권1호
• /
• pp.54-62
• /
• 2018

기술의 발전에 따라 다양한 응용을 위한 장치가 연구 및 개발되고 있으며 운전자 보조 시스템은 그 중 대표적인 기술이다. 운전자 보조 시스템 기술은 차량 주변의 정보를 인식하기 위해 영상인식 기법을 사용한다. 차량에 적용되는 운전자 보조 장치는 계산시간이 오래 걸리는 다수의 영상인식기법을 실시간으로 처리하는데 어려움이 존재한다. 이를 위해 제한된 하드웨어에서 영상인식 기법의 실시간 처리를 위한 동적 프레임 제외 기법을 제안한다. 기존의 연구에서 프레임 제외는 처리시간에 비례하여 정적으로 설정되었으며 처리 할 수 있는 영상인식기법의 수가 적음을 알 수 있다. 차량의 속도와 가속도를 통해 주행상태를 파악하여 동적으로 프레임 제외률을 설정하고 그에 맞게 영상인식 기법을 처리하여 그 수를 최대화시켰다. 실험을 통해 처리 수가 정적 기법에 비해 32.5% 상승함을 확인하였다.

• Journal of Construction Engineering and Project Management
• /
• 제9권3호
• /
• pp.1-21
• /
• 2019

The management of mega construction projects which incorporate a large number of stakeholders, technologies, data, work culture etc., is cumbersome. The experts in the construction arena advocate that interface management serves as a precise tool in resolving these conflict points due to the intricate nature of the construction projects. Interface management is a current trending management practice in the construction industry which is also a beneficiary to mega/fast track projects in enhancing the project performance. The main objective of this study is to validate a model for assessing the relationships among interface management, IT applications, project performance & project benefits. The mediating effect of interface management in relationship between project performance & interfacial factors was also investigated. The research model was validated using PLS-SEM (Partial Least Square-Structural Equation Modelling) approach. Data were collected from clients, contractors, consultants in large scale projects through questionnaire survey and smart-PLS software was used to analyse the conceptual model. The research model comprises eleven hypothesis and the significance of these hypothesis were tested using T- statistics values. The research implies that people/participants factor is greatly influenced by interface management with the path coefficient of 0.608 and also enhancement of project's schedule performance due to the interface management is strongly appealing (Path coefficient = 0.711). The results also reveal IT application is significantly associated with interface management practice (Path coefficient =0.723) and also the effect of IT application on project performance (schedule, cost, quality & safety) is successfully mediated through interface management practice. The practical application of this validated model was done through case study. The case study aims at measuring the impact of interface management on interfacial factors and role of interface management in improving the project performance in the construction organisations.

• 한국전산구조공학회논문집
• /
• 제33권2호
• /
• pp.113-119
• /
• 2020

사물인터넷 기반의 센서네트워크는 저렴한 비용으로 효율적으로 교량 등의 시설물 유지관리에 적용할 수 있는 한 방안이다. 본 연구에서는 사물인터넷 통신의 하나인, LoRa LPWAN 기반으로 교량 구조건전성모니터링을 위한 시스템을 개발하기 위해서 케이블 장력 모니터링을 위한 센서보드, 기존 계측 센서들과 함께 센서네트워크를 구축하기 위한 DAQ 보드, 데이터들 처리하고 LoRa 통신을 위한 스마트센서노드를 설계 및 제작하였으며 모니터링을 위한 센서네트워크를 구축하였다. 또한 본 시스템의 성능검증을 위해 영광대교에 Test Bed를 구축하여 교량 구조건전성 모니터링을 위한 센서네트워크에 적용가능성 여부를 살펴보았다. Test Bed 검증 결과 LoRa LPWAN 기반 센서네트워크는 데이터 전송률, 정확도, 경제성면에서 교량 구조 건전성 모니터링의 기술 중에 하나로 적용될 수 있으며, 향후 교량구조물 뿐만 아니라 다양한 공공기반 시설물에 유지관리를 위한 시스템으로 보급될 수 있기를 기대한다.

• Smart Structures and Systems
• /
• 제22권4호
• /
• pp.481-493
• /
• 2018

Ultrasonic guided waves have attracted increasing attention for non-destructive testing (NDT) and structural health monitoring (SHM) of bridge cables. They offer advantages like single measurement, wide coverage of acoustical field, and long-range propagation capability. To design defect detection systems, it is essential to understand how guided waves propagate in cables and how to select the optimal excitation frequency and mode. However, certain cable characteristics such as multiple wires, anchorage, and polyethylene (PE) sheath increase the complexity in analyzing the guided wave propagation. In this study, guided wave modes for multi-wire bridge cables are identified by using a semi-analytical finite element (SAFE) technique to obtain relevant dispersion curves. Numerical results indicated that the number of guided wave modes increases, the length of the flat region with a low frequency of L(0,1) mode becomes shorter, and the cutoff frequency for high order longitudinal wave modes becomes lower, as the number of steel wires in a cable increases. These findings were used in design of transducers for defect detection and selection of the optimal wave mode and frequency for subsequent experiments. A magnetostrictive transducer system was used to excite and detect the guided waves. The applicability of the proposed approach for detecting and locating wire breakages was demonstrated for a cable with 37 wires. The present ultrasonic guided wave method has been found to be very responsive to the number of brokenwires and is thus capable of detecting defects with varying sizes.

• Smart Structures and Systems
• /
• 제26권3호
• /
• pp.277-290
• /
• 2020

Disasters, including earthquakes and landslides, have enormous economic and social losses besides their impact on environmental disruption. Iran, and particularly its Western part, is known as an earthquake susceptible area due to numerous strong ground motions. Studying ecological changes due to climate change can improve the public and expert sector's awareness and response to future disastrous events. Synthetic Aperture Radar (SAR) data and Interferometric Synthetic Aperture Radar (InSAR) technologies are appropriate tools for modeling and surface deformation modeling. This paper proposes an efficient approach to detect ground deformation changes using Sentinel-1A. The focal point of this research is to map the ground surface deformation modeling is presented using InSAR technology over Sarpol-e Zahab on 25^th November 2018 as a study case. For surface deformation modeling and detection of the ground movement due to earthquake SARPROZ in MATLAB programming language is used and discussed. Results show that there is a general ground movement due to the Sarpol-e Zahab earthquake between -7 millimeter to +18 millimeter in the study area. This research verified previous researches on the advanced image analysis techniques employed for mapping ground movement, where InSAR provides a reliable tool for assisting engineers and the decision-maker in choosing proper policies in a time of disasters. Based on the result, 574 out of 682 damaged buildings and infrastructures due to the 2017 Sarpol-e Zahab earthquake have moved from -2 to +17 mm due to the 2018 earthquake with a magnitude of 6.3 Richter. Results show that mountainous areas have suffered land subsidence, where urban areas had land uplift.

• International journal of advanced smart convergence
• /
• 제7권1호
• /
• pp.42-47
• /
• 2018

Recently, as the demand for limited resources continues to rise and problems of resource depletion rise worldwide, the importance of renewable energy is gradually increasing. In order to solve these problems, various methods such as energy conservation and alternative energy development have been suggested, and biogas, which can utilize the gas produced from biomass as fuel, is also receiving attention as the next generation of innovative renewable energy. New and renewable energy using biogas is an energy production method that is expected to be possible in large scale because it can supply energy with high efficiency in compliance with energy supply method of recycling conventional resources. In order to more efficiently produce and manage these biogas, a biogas plant has emerged. In recent years, a large number of biogas plants have been installed and operated in various locations. Organic wastes corresponding to biogas production resources in a biogas plant exist in a wide variety of types, and each of the incoming raw materials is processed in different processes. Because such a process is required, the case where the biogas plant process is inefficiently operated is continuously occurring, and the economic cost consumed for the operation of the biogas production relative to the generated biogas production is further increased. In order to solve such problems, various attempts such as process analysis and feedback based on the feedstock have been continued but it is a passive method and very limited to operate a medium/large scale biogas plant. In this paper, we propose "CNN-based production yield prediction algorithm for increasing process efficiency of biogas plant" for efficient operation of biogas plant process. Based on CNN-based production yield forecasting, which is one of the deep-leaning technologies, it enables mechanical analysis of the process operation process and provides a solution for optimal process operation due to process-related accumulated data analyzed by the automated process.

• 산업경영시스템학회지
• /
• 제43권2호
• /
• pp.25-32
• /
• 2020

Data on patent and scientific paper is considered as a useful information source for analyzing technological information and has been widely utilized. Technology big data is analyzed in various ways to identify the latest technological trends and predict future promising technologies. Clustering is one of the ways to discover new features by creating groups from technology big data. Patent includes refined bibliographic information such as patent classification code whereas scientific paper does not have appropriate bibliographic information for clustering. This research proposes a new approach for clustering data of scientific paper by utilizing reference titles in each scientific paper. In this approach, the reference titles are considered as textual information because each reference consists of the title of the paper that represents the core content of the paper. We collected the scientific paper data, extracted the title of the reference, and conducted clustering by measuring the text-based similarity. The results from the proposed approach are compared with the results using existing methodologies that one is the approach utilizing textual information from titles and abstracts and the other one is a citation-based approach. The suggested approach in this paper shows statistically significant difference compared to the existing approaches and it shows better clustering performance. The proposed approach will be considered as a useful method for clustering scientific papers.

• 한국통신학회논문지
• /
• 제39C권11호
• /
• pp.1201-1208
• /
• 2014

해양 산업과 IT기술의 융합으로 해양 네트워크 시스템에 적용하기 위한 여러 가지 무선통신 기술들이 논의됨에 따라, 본 논문에서는 선박 간의 안정적인 통신을 위한 HARQ-ARQ interaction 기법을 제안하고, 모의실험을 통해 성능을 평가하였다. HARQ-ARQ interaction 기법에서 선박은 HARQ 피드백으로 ARQ 피드백을 대체함으로써, ARQ 블록의 재전송 시간을 단축시킨다. 그러나 HARQ 피드백 오류로 인하여 HARQ-ARQ interaction 기법에서 성능 열화가 발생할 수 있다. 따라서 본 논문은 HARQ-ARQ interaction 기법을 사용할 때 HARQ 피드백 메시지의 오류가 미치는 영향을 고려한다. 모의실험을 통하여 해양 네트워크 시스템에서 HARQ-ARQ interaction 기법을 사용함으로써 지연 성능을 향상시키는 것을 확인하였다.

• 한국통신학회논문지
• /
• 제39C권11호
• /
• pp.1139-1145
• /
• 2014

조선소는 다양한 용량 및 규격을 여러 사이트에서 제작하여 최종통합하기까지 여러 단계를 거치게 되며 이들 사이의 정보공유가 필수적이다. 최근 유무선통신망을 활용하여 조선소의 선박 건조 과정에서 다양한 멀티미디어 정보를 공유하는 조선 산업의 스마트화가 이루어지고 있다. 본 논문에서는 원격에 위치한 조선소에 적용할 수 있는 LTE 기반의 펨토셀 로컬 게이트웨이를 통해 상위 조선소와 중요정보를 주고받는 트래픽과 일반 트래픽을 분리하는 오프로드 방식을 제안하였다. 또한 조선소 내의 중복 요청되는 데이터에 대한 트래픽을 줄이기 위해 D2D 통신 기술을 적용하여 통신사업자의 IP 서비스 네트워크를 경유하지 않고 조선소 내의 기기간 통신을 지원하는 방안을 제안하였다. 이를 통해 이동통신망과 D2D, 광대역 인터넷 활용 기술을 조선 산업에 적용하여 조선소 산업 생산성 향상을 고려하였다.

• 한국전자통신학회논문지
• /
• 제15권4호
• /
• pp.687-694
• /
• 2020

SDN과 NFV은 차세대 네트워크 기술로서, 데이터센터, 캠퍼스, 대형회사 등 Cloud가 구축되어 있거나, 서비스 제공 중심의 통신회사 등에서 활발하게 적용하고 있다. 특히, 군(軍) 적용을 위해서는 국방통합데이터센터가 대표적인 예가 될 것이다. 국방통합데이터센터(DIDC)가 지능화된 센터로 도약하기 위해 최신 정보통신기술(ICT)을 적용한 「스마트 국방통합데이터센터」 추진에 박차를 가하고 있다. DIDC 설립 당시, Cloud 서비스 등의 인프라 구축을 30% 안팎의 수준으로 시작하여, 현재 'Cloud 퍼스트'를 통해 D-Cloud를 75%까지 확장할 예정이다. 또한, SDN/NFV 도입하므로 DIDC의 운용비용과 인력을 절감하고, 정보자원의 효율적인 이용과 사이버 정보보호체계에 대한 능력을 강화할 예정이며, 각 체계 사용에 유연성과 민첩성을 높여 앞으로 국방경영에 효율성에 이바지하기 위해 노력하고 있다. 이에 DIDC을 중심으로 SDN/NFV 도입의 당위성과 기대효과를 논하고자 한다.