• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.1
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• pp.54-63
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• 2023

In this paper, the effect of corrosion level and crack width on the cohesive strength-slip behavior of corroded steel rebar and concrete interface is conducted. The existing studies mainly focus on the decrease in bond strength with respect to the level of corrosion; there are, however, few studies on the decrease in cohesive strength according to the crack width of the concrete surface due to corrosion. Therefore, in this study, a series of tests for the cohesive strength, slip behavior and mass loss of the reinforcing bar is evaluated at the surface of corroded rebar and concrete. It is found that the tendency to decrease the bond strength is closely related to the crack width rather than the corrosion level. Hence, to determine the degradation performance for the bond strength-slip behavior relation, the occurrence of cracks on the concrete surface can be a suitable index.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.199-200
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• 2019

최근 의료서비스에 ICT 기술이 도입되면서 의료서비스 패러다임이 병원중심에서 환자 중심으로 변화되고 있다. 특히, 사물인터넷 기술은 스마트헬스케어 서비스를 현실화하고 있다. 이로인하여 병원이 아닌 곳에서도 환자의 상태를 확인할 수 있고 이에 대한 적절한 조치를 취할 수 있는 다양한 서비스를 개발 연구가 활발히 진행되고 있다. 그러나 의료 사각지대의 환자는 여전히 신속하게 조치를 못하는 실정이며, 관리가 되고 있지 않아 사회적인 문제로 이슈화되고 있다. 본 논문은 의료사각지대의 환자에 대한 의료영상 진단 지원을 위한 클라우드환경 기반의 Connected Radiology Care System을 제안하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.01a
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• pp.45-46
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• 2021

의료영상이란 의료영상장비로부터 DICOM이라는 의료영상표준에 따라 저장되며, 의료영상관리 시스템인 PACS를 통해 관리된다. 이러한, 의료영상장비 ICT기술이 융합되어 급격하게 발전되고 있으며 다양한 의료영상장치가 개발되어지고 있다. 하지만, 기술력은 높아지고 있으나 개발된 의료영상장비로부터 촬영된 영상품질관리에 대한 문제점이 제기되고 있다. 이와 관련하여 다기관의 의료영상장비 개발과 해당 기기로부터 수집된 의료영상에 대한 품질을 관리할 필요성이 증가하고 있다. 따라서 코로나 19와 같은 상황에서 의료기기 개발 지원과 관리를 비대면 관리서비스 시스템 개발과 의료영상장치 개발 정도를 관리할 수 있을 뿐만 아니라 의료영상에 대한 품질까지 모니터링하여 및 개선 할 수 있는 시스템을 제안하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3083-3098
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• 2023

As demands for efficient and echo-friendly production of marine products increase, smart aquaculture based on information and communication technology (ICT) has become a promising trend. The smart aquaculture is expected to control fundamental farm environment variables including water temperature and dissolved oxygen (DO) levels with less human intervention. A recirculating aquaculture system (RAS) is required for the smart aquaculture which utilizes a purification tank to reuse water drained from the water tank while blocking the external environment. Elaborate water treatment should be considered to properly operate RAS. However, analyzing the water treatment performance is a challenging issue because fish farm circumstance continuously changes and recursively affects water fluidity. To handle this issue, we introduce computational fluid dynamics (CFD) aided water treatment analysis including water fluidity and the solid particles removal efficiency. We adopt RAS parameters widely used in the real aquaculture field to better reflect the real situation. The simulation results provide several indicators for users to check performance metrics when planning to select appropriate RAS without actually using it which costs a lot to operate.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.265-270
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• 2016

The advance in mobile devices such as smartphone, wireless networking, and Internet technologies enables many organizations to improve drastically not only the ways of carrying out every job activity but also their business processes and operations management. As the effort to work smart utilizing the technological change, they are interested in the implementation of Smart Work environment. In this paper we examine several types of smart work and their service scenarios. We also describe the structures of networking and system configurations for building up the smart work environment. These study results may be useful as reference materials for the successful implementation of smart work.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.27-29
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• 2015

Based on IALA guidelines, the fundamental requirements of radar system for vessel traffic services are analyzed in this paper. target separation, target position accuracy, target track accuracy of X-band radar and recommended test conditions are analyzed. Also, in order to check if it satisfies the requirement of target position accuracy from IALA guideline, the test is carried out through processing of radar raw image acquired at VTS center.

• Journal of Platform Technology
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• v.11 no.1
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• pp.85-104
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• 2023

Since the late 1990s, the Korean government has attempted to develop the Architectural Information System (AIS, SEUMTER), led by the Ministry of Construction and Transportation, in order to improve civil complaint convenience and administrative efficiency in architectural administration. Since then, for nearly 30 years, the Korean government has been continuously upgrading the SEUMTER system. Based on these advancement projects, it is now possible to conduct civil affairs through the Internet, and civil petitioners can file complaints with government offices without visiting and without documents. In addition, statistical work and performance management became possible in real time for civil servants. And recently, by clouding the SEUMTER system, intelligent services have become possible. In this paper, the development process of the SEUMTER was divided into four stages and evaluated, and the main success factors were derived. The main success factors of SEUMTER are 1) Promotion as a National Agenda - Leadership of the President and Ministers, 2) Outsourcing of Information System Development and Dissemination, 3) Overcoming Selfishness between Ministries - Integrating Building Permits System and Building Ledger Systems, 4) Continue to Promote Information System Advancement. Subsequently, three global diffusion strategies for SEUMTER were presented: 1) the Need to Establish Globalization Strategy: Linkage with Smart City Business, 2) Small and Medium-sized System Model Needed for Globalization and ODA, and 3) System Success Needs to be Publicized Internationally.

• ETRI Journal
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• v.45 no.1
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• pp.105-118
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• 2023

We tested the feasibility of automated discrimination of patients with panic disorder (PD) from healthy controls (HCs) based on multimodal physiological responses using machine learning. Electrocardiogram (ECG), electrodermal activity (EDA), respiration (RESP), and peripheral temperature (PT) of the participants were measured during three experimental phases: rest, stress, and recovery. Eleven physiological features were extracted from each phase and used as input data. Logistic regression (LoR), k-nearest neighbor (KNN), support vector machine (SVM), random forest (RF), and multilayer perceptron (MLP) algorithms were implemented with nested cross-validation. Linear regression analysis showed that ECG and PT features obtained in the stress and recovery phases were significant predictors of PD. We achieved the highest accuracy (75.61%) with MLP using all 33 features. With the exception of MLP, applying the significant predictors led to a higher accuracy than using 24 ECG features. These results suggest that combining multimodal physiological signals measured during various states of autonomic arousal has the potential to differentiate patients with PD from HCs.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.305-307
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• 2023

현재 제조업에서 설비 라인 증축 및 최적화를 위해서는 공정 분석과 설비 시스템 테스트가 요구되며, 많은 시간과 비용이 소요된다. 이러한 문제를 해결하기 위해, 가상의 설비모델을 이용해 설비검증과 라인 테스트를 수행할 수 있는 다양한 CPS(Cyber Physical System)가 연구되고 있다. 본 논문에서는 다양한 설비 이해관계자 사이의 상호운용성을 확보하기 위해 독일의 Industry 4.0에서 제안한 표준 설비 명세인 AAS(Asset Administration Shell)를 활용한 CPS 구현을 제안한다. SMT(Surface Mounting Technology) 라인 중 Screen Printer를 대상으로, 총 3개의 서브 모델(Sub model)과 17개의 속성(Property)을 AAS 명세하고 이를 이용한 CPS를 구현하는 사례연구를 수행했다. 제안 방법은 표준명세를 활용한 제조 분야 CPS 구현에 적용될 수 있다.

• Journal of information and communication convergence engineering
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• v.22 no.1
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• pp.14-22
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• 2024

This study presents the design of a Wilkinson power divider for three-way output ports (WPD3OP), which incorporates a defected ground structure (DGS). An asymmetric power divider is integrated into the output ports of the conventional Wilkinson power divider (WPD), establishing a three-way output port configuration. The DGS introduces periodic or irregular patterns into the ground plane to suppress unwanted electromagnetic wave propagation, and its incorporation can enhance the performance of the power divider, in terms of the power-division ratio, isolation, and bandwidth, by reducing spurious resonances. The proposed design algorithm for an asymmetric power divider for three-way output ports is analyzed via circuit simulations using High-Frequency Simulation Software (HFSS). The results verify the validity of the proposed method. The analysis of the WPD3OP integrated with DGS certifies the achievement of a center frequency of 2 GHz. This confirmation is supported by schematic ideal design simulation results and measurements encompassing insertion losses, return losses, and isolation.