• 한국산업융합학회 논문집
• /
• 제23권2_1호
• /
• pp.125-137
• /
• 2020

Tracking micro-sized insects is one of the challenges of protecting ecosystems and biodiversity. In this study, we propose an approach for the autonomous tracking of micro-sized flying insects, and develop an unmanned aerial vehicle (UAV)-based robotic system. The Kalman filter is applied to the received signal strength emitted from radio telemetry to estimate the position while reducing the measurement error and noise. The autonomous tracking strategy is a method in which the UAV rotates at one point to measure the signal strength and control its position in the strongest direction of the signal. We also design a system architecture comprising a tracking sensor system and a UAV system for micro-sized insects. The estimation and autonomous tracking of the target position by the proposed system are verified and evaluated through dynamic simulation. Therefore, in this study, we propose and validate a UAV-based tracking system for micro-sized flying insects, which has not been proposed in studies conducted thus far.

• Smart Structures and Systems
• /
• 제32권1호
• /
• pp.61-81
• /
• 2023

This study presents an ensemble learning based Bayesian model updating approach for structural damage diagnosis. In the developed framework, the structure is initially decomposed into a set of substructures. The autoregressive moving average (ARMAX) model is established first for structural damage localization based structural motion equation. The wavelet packet decomposition is utilized to extract the damage-sensitive node energy in different frequency bands for constructing structural surrogate models. Four methods, including Kriging predictor (KRG), radial basis function neural network (RBFNN), support vector regression (SVR), and multivariate adaptive regression splines (MARS), are selected as candidate structural surrogate models. These models are then resampled by bootstrapping and combined to obtain an ensemble model by probabilistic ensemble. Meanwhile, the maximum entropy principal is adopted to search for new design points for sample space updating, yielding a more robust ensemble model. Through the iterations, a framework of surrogate ensemble learning based model updating with high model construction efficiency and accuracy is proposed. The specificities of the method are discussed and investigated in a case study.

• 제어로봇시스템학회논문지
• /
• 제16권9호
• /
• pp.898-904
• /
• 2010

Unmanned autonomous forklifts have a great potential to enhance the productivity of material handling in various applications because these forklifts can pick up and deliver loads without an operator and any fixed guide. There are, however, many technical difficulties in developing such forklifts including localization, map building, sensor fusion, control and so on. Implementation, which is often neglected, is one of practical issues in developing such an autonomous device. This is because the system requires numerous sensors, actuators, and controllers that need to be connected with each other, and the number of connections grows very rapidly as the number of devices grows. Another requirement on the integration is that the system should allow changes in the system design so that modification and addition of system components can be accommodated without too much effort. This paper presents a network-based distributed approach where system components are connected to a shared CAN network, and control functions are divided into small tasks that are distributed over a number of microcontrollers with a limited computing capacity. This approach is successfully applied to develop an unmanned forklift.

• 대한건축학회논문집:계획계
• /
• 제34권10호
• /
• pp.119-130
• /
• 2018

In the late 1950s, departing from their unquestioning following of Soviet architecture, North Koreans attempted to discover the specificities of traditional Korean architecture and apply them to their contemporary monuments. This paper examines the ways in which North Korean architects developed their unique version of Socialist realism in the making of Pyongyang Grand Theater. The traditional elements in harmony with North Korea's political ideology-an early form of Juche ideology-and modern building technologies were to be viewed as contemporary elements, and not as a simple revival of the past. This study applies Socialist realism's compositional principle "national in form and socialist in content" to Pyongyang Grand Theater and examines specifically what "socialist content" and "national form" were and how the two were combined in the construction of Pyongyang Grand Theater. By situating the building in the context of localization of Socialist realism which is universal art principle of the communist world, this study contributes to the deeper and wider understanding of North Korea's Modern Joseon Architecture.

• 아태비즈니스연구
• /
• 제12권3호
• /
• pp.117-136
• /
• 2021

Purpose - The research is aimed at investigating the dynamics of economic cooperation among countries which share historical and genetic affinity. Research design, data, and methodology - The study analyzed historical and genetic affinity after reviewing related thesis data on countries with historical relations studied by domestic historians. After that, it was applied to the method of designating the counterparts for economic cooperation and suggesting economic cooperation measures within a comprehensive range. Results - Economic cooperation with the counterparts should complement the ongoing economic cooperation with each country among their planned national strategies. Korea proposes such matters in a way that cooperates and develops to obtain mutual economic benefits. Among the associated countries, Mongolia is for the underground resource processing industry, Turkey for the investment of companies advancing into neighboring countries, Kazakhstan for the diversification of business centered on the manufacturing industry, Uzbekistan for the modernization and diversification of industrial production, Turkmenistan for the localization of resource-based industries and Export promotion, Hungary for the increase in investment in line with the East-ward policy, Finland is for the cooperation in the knowledge-based industry. Conclusion - This economic cooperation can raise Korea's international status to the next level and further strengthen our voice right in the international community.

• 한국프랜차이즈경영연구
• /
• 제14권3호
• /
• pp.17-35
• /
• 2023

Purpose: As more and more food franchise companies want to expand overseas, related research is becoming more and more necessary. This study aims to examine the critical factors for successful overseas expansion according to the stages of overseas expansion, derive vital associations, and examine the success factors of overseas expansion through semantic network analysis. Research Design, Data, and Methodology: This study conducted in-depth interviews with three food franchise companies that have experienced overseas expansion and conducted semantic network analysis among crucial associations. The semantic network analysis was conducted using the Textom program. Results: Based on the results of the in-depth interview analysis, the factors considered when expanding overseas were categorized as 1) standardization and localization strategies of overseas franchisees, 2) physical environment of overseas franchisees, 3) entry types of overseas franchisees, 4) constraints of overseas franchisees, and 5) success criteria of overseas franchisees. The semantic network analysis based on the corresponding keywords showed that the importance of local partners is very high in common. Conclusion: This study examined and re-categorized the important factors to consider when a restaurant franchise company expands overseas in a step-by-step manner. In addition, an attempt was made to examine the keywords derived from the semantic network analysis objectively. The results provided theoretical and practical implications for the successful overseas expansion of franchise companies.

• 건축역사연구
• /
• 제16권6호
• /
• pp.27-46
• /
• 2007

Through reinvestigations of early years of King Young-Joe provincial castles, Jeonju Eupsung, this study seeks to broaden the understanding of castle construction of the later period of Chosun Dynasty. Jeonju Eupsung was established by reform-minded king and his loyalist Cho, Hyun Myung. Their new conceptual framework for reconstruction of Jeonju Eupsung was affected by Yoo, Hyung Won, a realist scholar of 17th century. It is obvious that adopted new administrative systems of financing, building and maintaining of Jeonju Eupsung were based on the his theories of castle. This study demonstrates that Jeonju Eupsung built by Cho, Hyun Myung, during the early years of King Young-Joe were based on those new concepts and systems of the new age. The study shows that the designer of this castle had in mind efficient construction design and execution and effective defense of provincial towns located on flat ground. And, the study explains how those original designer sought higher productivity through greater localization of securing resources and more detailed and improved organization of construction responsibilities. In short, this study seeks to prove that the provincial castles of the early 18th century reflected the new thinking on practicality that was spreading throughout the society of Chosun Dynasty at the time.

• Smart Structures and Systems
• /
• 제1권2호
• /
• pp.141-158
• /
• 2005

A new design of distributed crack sensors based on the topological change of transmission line cables is presented for the condition assessment of reinforced concrete (RC) structures during and immediately after an earthquake event. This study is primarily focused on the performance of cable sensors under dynamic loading, particularly a feature that allows for some "memory" of the crack history of an RC member. This feature enables the post-earthquake condition assessment of structural members such as RC columns, in which the earthquake-induced cracks are closed immediately after an earthquake event due to gravity loads, and are visually undetectable. Factors affecting the onset of the feature were investigated experimentally with small-scale RC beams under cyclic loading. Test results indicated that both crack width and the number of loading cycles were instrumental in the onset of the memory feature of cable sensors. Practical issues related to dynamic acquisition with the sensors are discussed. The sensors were proven to be fatigue resistant from shake table tests of RC columns. The sensors continued to show useful performance after the columns can no longer support additional loads.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2009년도 추계학술발표대회
• /
• pp.181-182
• /
• 2009

본 논문에서는 IEEE 802.15.4a 근거리 무선 네트워크를 이용하여 다중 이동 로봇을 사용자 휴대 단말을 이용하여 실시간으로 편리하게 제어하기 위한 플랫폼을 설계하고 그 기본기능을 검증한다. 제안한 원격제어 플랫폼은 IEEE 802.15.4a 기반의 최초의 원격제어 플랫폼으로서 그 의의를 가지며, 자동 스페이싱(auto-spacing)을 기반한 다중 로봇 그룹이동과 IEEE 802.15.4a의 거리측정 기능과 초음파 및 자이로센서를 이용한 상대각측정 기능을 이용한 협동위치인식(cooperative localization) 기능을 제공하는데 기존 기법들과의 차별성이 존재한다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제49권3호
• /
• pp.186-195
• /
• 2000

In this paper, partial discharge (PD) measurement was performed to evaluate the quality of the cable joint and termination constructions. The resistive coupling technique for PD detection using resistivity of semiconducting layer of the cable in the accessories, such as joints and terminations. With high frequency PD (HEPD) measurement, an excellent sensitivity below 20pC could be achieved under unshielded condition. The localization of the defects in the accessories could be identified. During heating cycle, PDs were monitored and analyzed. At that time, the PDs were dependent on the temperature of the heating cycle and showed cyclic behaviors, which were attributed to local delamination of the interfaces, between epoxy unit and stress relief cone(SRC) and between SRC and cable, due to the difference of thermal expansion. As a conclusion, HFPD measurement technique was proven to be an effective diagnostic method for qualification of extra high voltage (EHV) cable accessories. With this technique, the optimal design of the components of the accessories could be verified not only in an early stage but also under operating condition. This technique would result in the improvement of the reliability of the EHV cable accessories.