• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.1
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• pp.34-41
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• 2002

In the conventional rake receiver structure for the IS-95 CDMA system, each finger has its own time-deskew buffer or FIFO that aligns the multipath signals to the same timing reference in order to combine symbols. This architecture is not a burden to the rake receiver design mainly because of the small number and size of the buffers. However, the number and size of the buffers are significantly increased in the cdma2000 system which adopts multiple carriers and the small spreading gain for a higher rate in data services. In order to decrease the number of buffers, we propose a new model of the time-deskew buffers, which combines the symbols as well as realigns them at the same time. Our architecture reduces the hardware complexity of the buffers by about more than 60% and 70% compared with the conventional one when we consider each rake receiver has three and four independent fingers, respectively. Moreover, the proposed algorithm is very useful not only to the cdma2000 rake receiver but also to the receiver with many fingers in order to increase the BER performance.

• Journal of KIISE:Software and Applications
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• v.31 no.2
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• pp.137-152
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• 2004

Assesment of 30 nutritional minerals and 8 toxic elements in hair are very important not only for determining adequacy, deficiencies and unbalance, but also for assessing their relative relationships in the body. A test has been developed that serves this purpose exceedingly well. This test is known as tissue mineral analysis(TMA). TMA is very popular method in hair mineral analysis for health care professionals in over 46 countries' medical center. However, there are some problems. First, they do not have database which is suitable for korean to do analyze. Second, as the TMA results from TEI-USA is composed of english documents and graphic files prohibited to open, its usability is very low. Third, some of them has low level database which is related to TMA, so hairs are sent to TEI-USA for analyzing and medical services. it bring about an severe outflow of dollars. Finally, TMA results are based on the database of american health and mineral standards, it is possibly mislead korean mineral standards. The purposes of this research is to develope the first Intelligent Medical Expert System(IMES) of TMA, in Korea, which makes clear the problems mentioned earlier IMES can analyze the tissue mineral data with multiple stage decision tree classifier. It is also constructed with multiple fuzzy rule base and hence analyze the complex data from Korean database by fuzzy inference methods. Pilot test of this systems are increased of business efficiency and business satisfaction 86% and 92% respectively.

• Korean Journal of Remote Sensing
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• v.14 no.4
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• pp.376-391
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• 1998

Images from satellites will have 1 to 3 meter ground resolution and will be very useful for analyzing current status of earth surface. An image processing system named GeoWatch with more intelligent image processing algorithms has been designed and implemented to support the detailed analysis of the land surface using high-resolution satellite imagery. The GeoWatch is a valuable tool for satellite image processing such as digitizing, geometric correction using ground control points, interactive enhancement, various transforms, arithmetic operations, calculating vegetation indices. It can be used for investigating various facts such as the change detection, land cover classification, capacity estimation of the industrial complex, urban information extraction, etc. using more intelligent analysis method with a variety of visual techniques. The strong points of this system are flexible algorithm-save-method for efficient handling of large size images (e.g. full scenes), automatic menu generation and powerful visual programming environment. Most of the existing image processing systems use general graphic user interfaces. In this paper we adopted visual program language for remotely sensed image processing for its powerful programmability and ease of use. This system is an integrated raster/vector analysis system and equipped with many useful functions such as vector overlay, flight simulation, 3D display, and object modeling techniques, etc. In addition to the modules for image and digital signal processing, the system provides many other utilities such as a toolbox and an interactive image editor. This paper also presents several cases of image analysis methods with AI (Artificial Intelligent) technique and design concept for visual programming environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.489-495
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• 2018

In this paper, we designed and fabricated WLAN / UWB communication antennas operating at 3.3 [GHz] and 5 [GHz] bands in order to effectively use the high-speed communication network system that improved antenna miniaturization, gain and radiation pattern. Microstrip patch antennas were chosen to improve the bandwidth. The slot width, length, and transmission line width were calculated using the theoretical formula for each step. Simulation results show that the return loss is -14.053 [dB] at 3.3 [GHz] and -13.118 [dB] at 5 [GHz]. The gain showed a value of 2.479 [dBi] at 3.3 [GHz] and a value of 3.317 [dBi] at 5 [GHz]. After optimizing it with the CST Microwave Studio 2014 program, which can be 3D-designed, Based on these results, we investigated the performance of antennas by measuring their characteristics. In recent years, WLAN, which is a variety of wireless technologies that are continuously developing, and UWB, which is a communication technology which is increasing in frequency band due to an increase in demand of the technology users, is used for a high speed wireless communication system. Communication seems to be possible.

• Korean Journal of Remote Sensing
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• v.38 no.3
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• pp.311-326
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• 2022

The Compact Advanced Satellite 500-4 (CAS500-4) is under development to efficiently manage and monitor forests in Korea and is scheduled to launch in 2025. The National Institute of Forest Science is developing 36 types of forestry applications to utilize the CAS500-4 efficiently. The products derived using the remote sensing method require validation with ground reference data, and the quality monitoring results for the products must be continuously reported. Due to it being the first time developing the national forestry satellite, there is no official calibration and validation site for forestry products in Korea. Accordingly, the author designed a calibration and validation site for the forestry products following international standards. In addition, to install calibration and validation sites nationwide, the authors selected appropriate sensors and evaluated the applicability of the sensors. As a result, the difference between the ground observation data and the Sentinel-2 image was observed to be within ±5%, confirming that the sensor could be used for nationwide expansion.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.115-127
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• 2021

With the development of science and technology around the world, the realm of cyberspace, following land, sea, air, and space, is also recognized as a battlefield area. Accordingly, it is necessary to design and establish various elements such as definitions, systems, procedures, and plans for not only physical operations in land, sea, air, and space but also cyber operations in cyberspace. In this research, the importance of cyber targets that can be considered when prioritizing the list of cyber targets selected through intermediate target development in the target development and prioritization stage of targeting processing of cyber operations was selected as a factor to be considered. We propose a method to calculate the score for the cyber target and use it as a part of the cyber target prioritization score. Accordingly, in the cyber target prioritization process, the cyber target importance category is set, and the cyber target importance concept and reference item are derived. We propose a TIR (Target Importance Rank) algorithm that synthesizes parameters such as Event Prioritization Framework based on PageRank algorithm for score calculation and synthesis for each derived standard item. And, by constructing the Stuxnet case-based network topology and scenario data, a cyber target importance score is derived with the proposed algorithm, and the cyber target is prioritized to verify the proposed algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.4
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• pp.284-291
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• 2017

There is no doubt that advances in UAV technology have improved military performance. However, these advances require humans to adapt to new and complex operational systems. UAV has been rapidly expanding to a variety of fields such as reconnaissance, transportation, communication and aerial photographing recently. Also, with the development of UAV automation technology, one operator is able to supervisory-control multiple-UAVs. However, as the number of assigned UAV increases, the amount of information increases and this results in the workload of the operator increasing and deterioration in controlling performance. Accordingly, there is a need for a model to determine the level of overload an operator may encounter with regard to multiple-UAV but nationally this kind of research is currently lacking. Therefore, this paper provides an experimental platform for evaluating workload index effectiveness integrating multiple-UAV operational environments, GCS, and eye-tracking system followed by a limited survey of domestic and international studies of multi-UAV overload studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4177-4185
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• 2012

LEDs are becoming the most suitable candidate replacing traditional fluorescent lamps because of its eco-friendly characteristics. LEDs are also actively used to design green building system and to make outdoor billboard as a back-light system due to its high energy efficiency. In this paper, we have developed AC direct driver for $12{\times}12$ FLB(flexible LED board) and LED flat light without SMPS. It has LID-PC-R101B driver IC that can support the high power factor and be composed of LED switching circuit in group. Also, an elaborate system designs can guarantee a high luminous efficiency, a high reliability and a low power consumption. The proposed FLB has the ultra slim shape of $450{\times}450$ mm, width of 4 mm and weight of 280 g. In the end, we have developed a prototype of FLB for billboard and flat light for room lighting with AC direct driver iposrder to verify the performance of the proposed system.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.510-518
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• 2018

Recently, lots of interests have been concentrated on the scrubber system that abates waste gases produced from semiconductor manufacturing processes. An effective design of the thermal decomposition reactor inside a scrubber system is significantly important since it is directly related to the removal performance of pollutants and overall stabilities. In the present study, a computational fluid dynamics (CFD) analysis was conducted to figure out the thermal and flow characteristics inside the reactor of wet scrubber. In order to verify the numerical method, the temperature at several monitoring points was compared to that of experimental results. Average error rates of 1.27~2.27% between both the results were achieved, and numerical results of the temperature distribution were in good agreement with the experimental data. By using the validated numerical method, the effect of the reactor geometry on the heat transfer rate was also taken into consideration. From the result, it was observed that the flow and temperature uniformity were significantly improved. Overall, our current study could provide useful information to identify the fluid behavior and thermal performance for various scrubber systems.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.11
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• pp.820-829
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• 2006

Wireless sensor networks consisting of hundreds to thousands of nodes are expected to be increasingly deployed in coming years, as they enable reliable monitoring and analysis of physical worlds. These networks have unique features that are very different from traditional networks, e.g., the numerous numbers of nodes, limitation in power, processing, and memory. Due to these unique features of wireless sensor networks, sensor data management including querying becomes a challenging problem. Furthermore, due to wide popularization of the Internet and its facility in use, it is generally accepted that an unattended network can be efficiently managed and monitored over the Internet. In particular, in order to more efficiently query and manage data in a sensor network. in this paper, the architecture of a sensor gateway including web-based query server is presented and its implementation detail is illustrated. The presented web-based gateway is largely divided into two important parts: Internet part and sensor network part. The sensor network part plays an important role of handling a variety of sensor networks, including flat or hierarchical network architecture, by using internally layered architecture for efficiently querying and managing data in a sensor network. In addition, the Internet part provides a modular gateway function for favorable exchange between the sensor network and Internet.