• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.4
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• pp.1-8
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• 2011

Traditional transactional memory systems are no longer able to guarantee the performance of diverse applications with overflowed transactions since there is the drawback that tracking the data for logging is difficult. Especially, this mechanism has a disadvantage of increasing communication delay for sustaining the state which is required to detect the conflict on the overflowed transactions from the first level cache in the transactional memory systems. To address this point, we have focused on the cache architecture of the systems to reduce the overhead caused by overflows and cache misses. In this paper, we present Supportive Cache which reduces additional overhead during transactions. Supportive Cache performs a parallel look-up with L1 private cache and uses the same replacement policy as L1 private cache. We evaluate the performance of the proposed design by comparing LogTM-SE with and without Supportive Cache. The simulation results show that our system improves the performance by 37% on average, compared to the original LogTM-SE which uses the same hardware resource.

• Convergence Security Journal
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• v.10 no.4
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• pp.39-48
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• 2010

In a complex, secure IT system environment there will be groups of data that be segregated from one another, yet reside on the same system. Users of the system will have varying degrees of access to specific data. The Configuration Management(CM) of the information architecture, the physical architecture, user privileges and application security policies increases the complexity for operations, maintenance and security staff. This pager describes(current work to merge the capabilities of a network CM toll with those of a Computer Aided System Engineering(CASE) tool. The rigour of Systems Engineering(SE) modelling techniques can be used to deal with the complexities of multi-level information security. The SE logical and physical models of the same system are readily tailorable to document the critical components of both the information architecture and physical architecture that needs to be managed. Linking a user-friendly, physical CM tool with the extended capabilities of a CASE tool provide the basis for improved configuration management of secure IT systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1837-1860
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• 2020

We propose a general framework for studying resource allocation problem and the tradeoff between spectral efficiency (SE) and energy efficiency (EE) for downlink traffic in power domain-non-orthogonal multiple access (PD-NOMA) and device to device (D2D) based heterogeneous cloud radio access networks (H-CRANs) under imperfect channel state information (CSI). The aim is jointly optimize radio remote head (RRH) selection, spectrum allocation and power control, which is formulated as a multi-objective optimization (MOO) problem that can be solved with weighted Tchebycheff method. We propose a low-complexity algorithm to solve user association, spectrum allocation and power coordination separately. We first compute the CSI for RRHs. Then we study allocating the cell users (CUs) and D2D groups to different subchannels by constructing a bipartite graph and Hungrarian algorithm. To solve the power control and EE-SE tradeoff problems, we decompose the target function into two subproblems. Then, we utilize successive convex program approach to lower the computational complexity. Moreover, we use Lagrangian method and KKT conditions to find the global optimum with low complexity, and get a fast convergence by subgradient method. Numerical simulation results demonstrate that by using PD-NOMA technique and H-CRAN with D2D communications, the system gets good EE-SE tradeoff performance.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.39-47
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• 2021

With rising concerns about pesticide spray drifts, this study analyzed the drift patterns of two typically-used nozzles, XR nozzle and AI nozzle, concerning their working pressures and wind speeds by wind tunnel experiments. AI nozzle showed low drift potential with larger droplet sizes compared to XR nozzle. Airborne and deposition drifts of XR nozzle were two times higher than those of AI nozzle under high wind speeds (≥2 m s^-1). In all cases, higher working pressures decreased the droplet sizes, thereby increasing the airborne and deposition drifts. Higher wind speeds also resulted in more airborne drifts, while ground deposition was increased under lower wind speeds. These effects of working pressures and wind speeds on the airborne and deposition drifts were observed at leeward distances less than 4 m from the nozzles. However, the airborne and deposition drifts were barely affected by the working pressures and wind speeds at leeward distances more than 11 m. The measurements were fitted to regression models of the drift curve with acceptable R² values greater than 0.8, demonstrating that further studies will be useful to settle domestic issues of spray drifts.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.11
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• pp.1017-1026
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• 2015

Infrared (IR) target detection is one of the key technologies in Automatic Target Detection/Recognition (ATD/R) for military applications. However, IR sensors have limitations due to the weather sensitivity and atmospheric effects. In recent years, sensor information fusion study is an active research topic to overcome these limitations. SAR sensor is adopted to sensor fusion, because SAR is robust to various weather conditions. In this paper, a Boolean Map Visual Theory-Morphology (BMVT-M) method is proposed to detect targets in SAR and IR images. Moreover, we suggest the IR and SAR image registration and decision level fusion algorithm. The experimental results using OKTAL-SE synthetic images validate the feasibility of sensor fusion-based target detection.

• Journal of IKEEE
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• v.12 no.1
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• pp.27-33
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• 2008

The demand of wireless communication is increased rapidly due to the development of wireless communication systems, and many people have the great interest about the "RF system". The trend of the RF audio system is to design the system with less power consumption. In this paper, we explain the Software Algorithm Design of RF systems that is suitable for low power consumption.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.479-484
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• 2000

The topology optimization of electromagnetic systems is investigated and the TOPEM (Topology Optimization for Electromagnetic Systems) is developed using the finite element method (FEM). The design sensitivity equation for topology optimization is derived using the adjoint variable method. The proposed method is validated by applying it to the topology optimizations of a C-core actuator and an optical pickup actuator.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.429-430
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• 2017

본 논문은 챗봇을 활용하여 반복적인 입시 질문을 응답하는 시스템에 설계하였다. 1회성 응답 대신 문맥을 기억하여 사용자의 의도를 파악하고 자세한 응답을 제공한다. 또한, 한글 처리와 입시 관련 데이터베이스 연동을 통해 일반화 할 수 있는 유연성을 갖는 구조이며, 반복적인 질의응답을 챗봇으로 대신할 수 있을 것으로 기대된다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.255-256
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• 2019

본 논문에서는 물체를 집기(picking) 위해 필요한 깊이 값을 특수카메라인 리얼센스를 사용하여 받아와서 2D 카메라로는 하지 못하는 로봇 팔 피킹 시스템을 구현하였다. 객체 인식은 텐서플로우 객체 검출 라이브러리를 사용하여 정확도를 높였고, ROS 기반의 rviz, moveit, gazebo 등의 패키지를 사용하여 아두이노와 통신하며 로봇팔 하드웨어로 인식된 객체를 피킹하는 시스템을 구현하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.59-62
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• 2016

본 논문에서는 실종자 데이터베이스에 등록된 실종자에 대한 색인으로 텍스트 기반의 통제 색인만을 사용할 때 발생하는 문제점에 대한 해결책을 다룬다. 기존 실종자를 등록할 때 함께 등록하게 되는 실종자에 대한 이미지는 정형화 할 수 없어 실종자 조회에 사용될 수 없었다. 이러한 문제점을 해결하고자 OpenCV와 TensorFlow 를 이용하여 영상의 유사도를 추출함으로써 실종자의 이미지를 정형화시켜 유의미한 정보로 변경하여 사용하고자 하는 방법을 제안한다.