• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.37-47
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• 2016

The practical constraints on the commercial FPGAs which contain dedicated wide function multiplexers in their slice structure are incorporated with one of the most advanced FPGA mapping algorithms based on the AIG (And-Inverter Graph), one of the best logic representations in academia. As the first step of the mapping process, cuts are enumerated as intermediate structures. And then, the cuts which can be mapped to the multiplexers are recognized. Without any increased complexity, the delay and area of multiplexers as well as LUTs are calculated after checking the requirements for the tree construction such as symmetry and depth limit against dynamically changing mapping of neighboring nodes. Besides, the root positions of multiplexer trees are identified from the RTL code, and annotated to the AIG as AOs (Auxiliary Outputs). A new AIG embedding the multiplexer tree structures which are intentionally synthesized by Shannon expansion at the AOs, is overlapped with the optimized AIG. The lossless synthesis technique which employs FRAIG (Functionally Reduced AIG) is applied to this approach. The proposed approach and techniques are validated by implementing and applying them to two RISC processor examples, which yielded 13~30% area reduction, and up to 32% delay reduction. The research will be extended to take into account the constraints on the dedicated hardware for carry chains.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.19-31
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• 2013

Since the high readable source codes help us to understand and modify the program, it is much easy to maintain them. The readability of source code is not only affected by the complexity of algorithms such as control structures but also affected by the coding styles such as naming and indentation. Although various coding standards have been presented for promoting the readability of source codes, it has been usually lost or ignored in a programming course. One of the reasons is that the coding standard is not a hard-and-false rule since it does not contribute to the performance of software. In this paper, we propose a simple automatic system, namely StyleJigsaw, which checks the style of the source codes written by C/C++ or Java. In this system, the coding style score is calculated and visualized as a jigsaw puzzle. To measure the educational effectiveness of StyleJigsaw, several experiments have been conducted on a class students in C++ programming course. According to the experimental results, the coding style score increased about 8.0 points(10.9%) on average using StyleJigsaw. Further, according to a questionnaire survey targeting the students who attended the programming course, about 88.5% of the students responded that StyleJigsaw was of help to learn the coding standards. We expect that the StyleJigsaw can be effectively used to encourage the students to obey the coding standards, resulting in high readable programs.

• Journal of Convergence Society for SMB
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• v.3 no.2
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• pp.51-56
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• 2013

Real-time processing of sensor data network, is one of the important factors. Each node in the detected data are required to be transmitted within a certain time since the accurate processing is possible. Thus, the data nodes are successfully delivered within a specified time, it is very important to check whether the. Recently more and more accurate real-time embedded systems are reliable and haejyeoseo been able to provide sophisticated services. Because of the inherent complexity of embedded systems in the physical world and the difficulty of predicting the difficulty of a safe design constraints on the runtime violation of system as to cause unexpected causes. Each node data in time detected by the time required to be passed in the appropriate processing is possible because the data transfer time in this paper, the monitoring of the sensor network through a node are allowed to exist within the time range and transmits data to the server Analysis of the data transfer time for checking whether the system was implemented. Implementation of the data transmission time to the process for analyzing and presenting, according to the procedure suggested by the transit time required for analysis a time difference analysis method, a data collection method and a data transmission time and transmission time calculating method presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6A
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• pp.341-350
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• 2003

In this paper, we evaluate the performance of a moving average (MA) channel estimation filter when space-time block coding transmit diversity (STBC-TD) is applied to the wideband direct sequence code division multiple access (WCDMA) forward link. And we present the infinite impulse response (IIR) filter scheme that can reduce the required memory buffer and the channel estimation delay time. This paper also compares the performance between MA filter scheme and IIR filter scheme in various Rayleigh fading channel environments through the bit error rate (BER) and the frame error rate (FER). Extensive computer simulation results show that transmission with STBC-TD provides a significant gain in performance over no transmit diversity technique, particularly at pedestrian speeds. If STBC-TD technique is employed in the channel estimator based on MA filter, it provides considerable performance gains against Rayleigh fading and reduces the optimum filter tap number. Consequently, the channel estimation delay time and the complexity of the receiver are reduced. In addition, the channel estimator based on IIR filter has the advantages such as little memory requirement and no delay time compared to the MA scheme. However, IIR filter coefficients is very sensitive to the mobile speed change and it exerts a serious influence upon the performance. For that reason, it is important to set uP the optimum IIR filter coefficients.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.1-8
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• 2020

Communication between system modules is applied using the Modbus protocol in industrial sites including smart factories, industrial drones, building energy management systems, PLCs, ships, trains, and airplanes. The existing Modbus was used for serial communication, but the recent Modbus protocol is used for TCP/IP communication.The Modbus protocol supports RTU, TCP and ASCII, and implements and uses protocols in embedded systems. However, the transmission I/O devices for RTU, TCP, and ASCII-based protocols may differ. For example, RTU and ASCII communications transmit on a serial-based communication protocol, but in some cases, Ethernet TCP/IP transmission is required. In particular, since the C language (object-oriented) is used in embedded systems, the complexity of source code related to I/O registers increases. In this study, we designed software that can logically separate I/O functions from embedded devices, and designed the execution logic of each instance requiring I/O processing through a delegate class instance with Modbus RTU, TCP, and ASCII protocol generation. We designed and experimented with software that can separate communication I/O processing and logical execution logic for each instance.

• Tunnel and Underground Space
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• v.31 no.3
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• pp.167-183
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• 2021

It is essential to understand the complex thermo-hydro-mechanical-chemical (THMC) coupled behavior in the engineered barrier system and natural barrier system to secure the high-level radioactive waste repository's long-term safety. The heat from the high-level radioactive waste induces thermal pressurization and vaporization of groundwater in the repository system. Groundwater inflow affects the saturation variation in the engineered barrier system, and the saturation change influences the heat transfer and multi-phase flow characteristics in the buffer. Due to the complexity of the coupled behavior, a numerical simulation is a valuable tool to predict and evaluate the THMC interaction effect on the disposal system and safety assessment. To enhance the knowledge of THMC coupled interaction and validate modeling techniques in geological systems. DECOVALEX, an international cooperation project, was initiated in 1992, and KAERI has participated in the projects since 2008 in Korea. In this study, we introduced the main contents of all tasks in the DECOVALEX-2023, the current DECOVALEX phase, to the rock mechanics and geotechnical researchers in Korea.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1221-1221
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• 2022

Studying abroad in and of itself should be a unique and transformational learning experience for university students. Too often, "study abroad" is a code word for "faculty vacation" or "easy credit hours". For an international learning experience to be truly transformational it must offer an intense and directed program that maximizes the time the student spends in the accumulation of information that is new or different from what the student has "learned" previously. "Study abroad" may be a misnomer because it is not only about studying in another country or culture, that is, taking courses that usually have an attendance time of a few hours a week, but it is also about living in another country which becomes a 24/7 learning experience. Providing these programs during the Covid-19 pandemic has been a keen opportunity for institutional learning. When this immersion in foreign culture is combined with academic rigor applied to a student's chosen field of study the growth can be exponential. So, what is the relationship between academic and personal growth? The National Association for Study Abroad has found that "students who have studied abroad are better able to work with people from other countries, understand the complexity of global issues, and have greater intercultural learning. One study found that students returned from their study abroad experiences more tolerant and less fearful of other countries, but with a greater sense of nationalism-a phenomenon they called 'enlightened nationalism'." It is often said that "you only really learn to appreciate things that are important to you when they are gone, when you miss them." The international learning environment can provide this opportunity. The restrictions on various societies in the past two years due to the international Covid pandemic have provided existing study abroad programs with a true testing ground for the validity of their programs. At the end of the day, American colleges and universities are not helpless in the face of these developments. A lot depends on how a university positions itself for a future based on the uncertainties of the past. As Winston Churchill was working to form the United Nations after WWII, he famously said, "Never let a good crisis go to waste". In another context, Churchill's insight on human nature can also be applied to the coming semesters and years as studying abroad rebounds. What new strategies will be developed and maintained? Institutional commitment without fear will be necessary to assure that "studying abroad" will continue to develop as a truly unique and transformational learning experience.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.6 s.360
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• pp.40-47
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• 2007

In this paper, we propose and analyze the Adaptive Modulation System with optimal Turbo Coded V-BLAST(Vertical-Bell-lab Layered Space-Time) technique that adopts the extrinsic information from MAP (Maximum A Posteriori) Decoder with Iterative Decoding as a priori probability in two decoding procedures of V-BLAST; the ordering and the slicing. Also, we consider and compare the Adaptive Modulation System using conventional Turbo Coded V-BLAST technique that is simply combined V-BLAST with Turbo Coding scheme and the Adaptive Modulation System using conventional Turbo Coded V-BLAST technique that is decoded by the ML (Maximum Likelihood) decoding algorithm. We observe a throughput performance and a complexity. As a result of a performance comparison of each system, it has been proved that the complexity of the proposed decoding algorithm is lower than that of the ML decoding algorithm but is higher than that of the conventional V-BLAST decoding algorithm. however, we can see that the proposed system achieves a better throughput performance than the conventional system in the whole SNR (Signal to Noise Ratio) range. And the result shows that the proposed system achieves a throughput performance close to the ML decoded system. Specifically, a simulation shows that the maximum throughput improvement in each MIMO scheme is respectively about 350 kbps, 460 kbps, and 740 kbps compared to the conventional system. It is suggested that the effect of the proposed decoding algorithm accordingly gets higher as the number of system antenna increases.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3159-3174
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• 1997

This paper reports a research to develop a methodology and a tool for understanding of very large and complex real-time software. The methodology and the tool mostly developed by the author are called the Architecture-based Real-time Software Understanding (ARSU) and the Software Re/reverse-engineering Environment (SRE) respectively. Due to size and complexity, it is commonly very hard to understand the software during reengineering process. However the research facilitates scalable re/reverse-engineering of such real-time software based on the architecture of the software in three-dimensional perspectives: structural, functional, and behavioral views. Firstly, the structural view reveals the overall architecture, specification (outline), and the algorithm (detail) views of the software, based on hierarchically organized parent-chi1d relationship. The basic building block of the architecture is a software Unit (SWU), generated by user-defined criteria. The architecture facilitates navigation of the software in top-down or bottom-up way. It captures the specification and algorithm views at different levels of abstraction. It also shows the functional and the behavioral information at these levels. Secondly, the functional view includes graphs of data/control flow, input/output, definition/use, variable/reference, etc. Each feature of the view contains different kind of functionality of the software. Thirdly, the behavioral view includes state diagrams, interleaved event lists, etc. This view shows the dynamic properties or the software at runtime. Beside these views, there are a number of other documents: capabilities, interfaces, comments, code, etc. One of the most powerful characteristics of this approach is the capability of abstracting and exploding these dimensional information in the architecture through navigation. These capabilities establish the foundation for scalable and modular understanding of the software. This approach allows engineers to extract reusable components from the software during reengineering process.