• Journal of Satellite, Information and Communications
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• v.7 no.2
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• pp.97-103
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• 2012

A very low complexity QRD-M algorithm based on limited search area is proposed for MIMO systems. The conventional QRD-M algorithm calculates Euclidean distance between all constellation symbols and the temporary detection symbol at each layer. We found that performance will not be degraded even if we adaptively restrict the search area of the candidate symbols only to the neighboring points of temporary detection symbol according to the channel condition at each layer. As a channel condition indicator, we employ the channel gain ratio among the layers without necessity of SNR estimation. The simulation results show that the proposed scheme effectively achieves near optimal performance while maintaining the overall average computation complexity much smaller than the conventional QRD-M algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1180-1184
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• 2006

In a speech coding system using excitation source of voiced and unvoiced, it would be a distortion of speech quality in a voiced and an unvoiced consonants in a frame. In this paper, I propose a new multi-pulse coding method make use of V/S/TSIUVC switching and TSIUVC approximation-synthesis method in order to restrict a distortion of speech quality. The TSIUVC is extracted by using the zero crossing rate and individual pitch pulse. And the TSIUVC extraction rate was 91% for female voice and 96.2% for male voice. The important thing is that the frequency information of 0.547kHz below and 2.813kHz above can be made with high quality synthesis waveform within TSIUVC. I evaluated the MPC of V/UV and FBD-MPC of V/S/TSIUVC. As a result, the synthesis speech of FBD-MPC was better in speech quality than the MPC.

• Korean Security Journal
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• no.29
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• pp.7-34
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• 2011

Achieving high-level technology in fields such as IT-related industry, semiconductors, mobile phones, LCD, automobile, shipbuilding, etc., Korea has become an international market leader in those fields. In results, there are the increasing numbers of technology leakage attempts in various manners. Recently, technology leakages are not limited to illegal industrial espionage, but also occur during usual corporate proceedings such as technology transfer, joint research and M&A. In fact, there was a technology leakage issue in the M&A between Ssangyong Motors of Korea and Shanghai Motors of China. Current M&A regulations of Korea are not independent laws, but are spread over various laws, such as commercial law, Capital Markets and the Financial Investment Services Act, Foreign Trade Act, etc. This paper focuses on whether the current Korean regulations regarding M&A are able to effectively restrict the leakage of major information of corporate during M&A and seeks the complements.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.11
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• pp.549-560
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• 2001

Cluster system provides attractive scalability in terms of compution power and memory size. With the advances in high speed computer network technology, cluster systems are becoming increasingly competitive compared to expensive MPPs (massively parallel processors). Load balancing is very important issue since an inappropriate scheduling of tasks cannot exploit the true potential of the system and can offset the gain from parallelization. In parallel processing program, it is difficult to predict the load of each task before running the program. Furthermore, tasks are interdependent each other in many ways. The dynamic load balancing algorithm, which evaluates each processor's load in runtime, partitions each task into the appropriate granularity and assigns them to processors in proportion to their performance in cluster systems. However, if the communication cost between processing nodes is expensive, it is not efficient for all nodes to attend load balancing process. In this paper, we restrict a processor that attend load balancing by the communication cost and the deviation of its load from the average. We simulate various models of the cluster system with parameters such as communication cost, node number, and range of workload value to compare existing load balancing methods with the proposed dynamic algorithms.

• Korean Journal of Remote Sensing
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• v.19 no.4
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• pp.291-305
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• 2003

The cost of deploying Geological and Environmental information gathering systems, especially when such systems obtain remote sensing and photographic data through the use of commercial satellites and aircraft. Besides the high cost equipment required, adverse weather conditions can further restrict a researcher's ability to collect data anywhere and anytime. To mitigate this problem, we have developed a compact, multi-spectral automatic Aerial photographic system. This system's Multi-spectral camera is capable of the visible (RGB) and infrared (NIR) bands (3032*2008 pixel). It consists of a thermal infrared camera and automatic balance control, and can be managed by a palm-top computer. Other features includes a camera gimbal system, GPS receiver, weather sensor among others. We have evaluated the efficiency of this system in several field tests at the following locations: Kyongsang-bukdo beach, Nakdong river (at each site of mulkeum-namji and koryung-gumi), and Kyungahn River. Its tested ability in aerial photography, weather data, as well as GPS data acquisition demonstrates its flexibility as a tool for environmental data monitoring.

• Convergence Security Journal
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• v.21 no.1
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• pp.55-62
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• 2021

Recently, the use of sensor devices is gradually increasing. As various sensor device emerge and the related technologies advance, there has been a dramatic increase in the interest in heterogeneous wireless sensor networks (WSNs). While sensor device provide us many valuable benefits, automatically and remotely supported services offered and accessed remotely through WSNs also exposes us to many different types of security threats. Most security threats were just related to information leakage and the loss of authentication among the involved parties: users, sensors and gateways. An user authentication protocol for wireless sensor networks is designed to restrict access to the sensor data only to user. In 2019, Chen et al. proposed an efficient user authentication protocol. However, Ryu et al. show that it's scheme still unstable and inefficient. It cannot resist offline password guessing attack and session key attack. In this paper, we propose an improved protocol to overcome these security weaknesses by storing secret data in device. In addition, security properties like session-key security, perfect forward secrecy, known-key security and resistance against offline password attacks are implied by our protocol.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.1
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• pp.1-9
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• 2021

Number of duck and its breeding facilities have been steadily decreasing for financial and social issues in Korea. Therefore, the 'turning point' for duck industry is strongly demanded. In this study, the questionary survey was carried out to provide backgrounds for developing policy and technology for duck breeding farms. The questionary survey aimed to investigate the information of operation strategy of farm, ventilation, cooling and heating. The total number of survey respondents was 74. In case of facility type, 55.4% of respondents stated they used greenhouse type, 31.3% for winch-curtain type, and 2.7% for windowless type (mechanically ventilated facility). More than 85% of the facilities were using 'natural ventilation', it meant that these situation can restrict the not only environmental control but also the supply policy for 'smart farm' of the Government. 44.6% used the combination of the cross-ventilation method and roof-ventilation method for ventilation operation in summer season, and 31.1% followed only the cross-ventilation method. In case of winter season, 36.5% used the cross-ventilation method, and 33.3% used the combination of cross and roof-ventilation, method. For the ventilation strategy, about 86.5% depended on farmer's experience. In case of heating and cooling, 79.7% were using kerosene heater for winter season, and 43.2% were using mist-spray for summer season, respectively. More than 75% stated that cooling and heating strategies were based on farmer's experience. From the analyses of the survey results, a few proposals for developing policy and technology for duck breeding farm was suggested.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.304-305
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• 2022

Recently, as digital communication technology is widely applied to the maritime field, large amounts of maritime data are being accumulated. Accordingly, attempts to create new value by applying data science and Artificial Intelligence(AI) technologies are emerging. Typically, Ministry of Oceans and Fisheries has been providing korean e-Navigation service since 2021 based on LTE-Maritime communication network, as well as R&D for creating value-added service through analyzing huge-sized maritime traffic data is underway. By the way, to do any data-based research, legal system, as a research infra, that researchers can get the data whenever they need is essential. This paper looked at types of data in maritime fields, checked related legal system about scientific analysis and utilization. It is confirmed that there are some legal factors which restrict its scientific analysis and utilization, and suggested ways of improvement to boost R&D using maritime data as a conclusion.

• Land and Housing Review
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• v.15 no.2
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• pp.19-28
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• 2024

This study analyzes the potential to achieve carbon neutrality through the technical definition and case studies of carbon-neutral buildings. In line with the Paris Agreement of December 2015, the global community has committed to limiting the average temperature rise to below 2oC and striving to restrict it to 1.5oC above pre-industrial levels. Achieving this requires reaching a net-zero state by 2050 and necessitates transitions across various sectors including energy, land use, and transportation. This research explores the technological approaches and real-world examples of carbon-neutral buildings, assessing their feasibility and limitations. By examining the definition of carbon-neutral buildings and presenting various technological solutions and case studies from both domestic and international contexts, this study evaluates the effectiveness and practicality of carbon-neutral buildings. The findings offer specific guidelines for the design, construction, and operation of carbon-neutral buildings and provide practical information for policymakers and practitioners aiming to create sustainable built environments.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.187-195
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• 2013

Most of former studies for car license plate detection restrict the image acquisition environment. The aim of this research is to diminish the restrictions by proposing a new method of using SIFT and neural network. SIFT can be used in diverse situations with less restriction because it provides size- and rotation-invariance and large discriminating power. SIFT extracted from the license plate image is divided into the internal(inside class) and the external(outside class) ones and the classifier is trained using them. In the proposed method, by just putting the various types of license plates, the trained neural network classifier can process all of the types. Although the classification performance is not high, the inside class appears densely over the plate region and sparsely over the non-plate regions. These characteristics create a local feature map, from which we can identify the location with the global maximum value as a candidate of license plate region. We collected image database with much less restriction than the conventional researches. The experiment and evaluation were done using this database. In terms of classification accuracy of SIFT keypoints, the correct recognition rate was 97.1%. The precision rate was 62.0% and recall rate was 50.2%. In terms of license plate detection rate, the correct recognition rate was 98.6%.