• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.8
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• pp.1489-1496
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• 2010

A feed forward differential architecture of analog PRML decoder is investigated to implement on analog parallel processing circuits. The conventional PRML decoder performs the trellis processing with the implementation of single stage in digital and its repeated use. The analog parallel processing-based PRML comes from the idea that the decoding of PRML is done mainly with the information of the first several number of stages. Shortening the trellis processing stages but implementing it with analog parallel circuits, several benefits including higher speed, no memory requirement and no A/D converter requirement are obtained. Most of the conventional analog parallel processing-based PRML decoders are differential architecture with the feedback of the previous decoded data. The architecture used in this paper is without feedback, where error metric accumulation is allowed to start from all the states of the decoding stage, which enables to be decoded without feedback. The circuit of the proposed architecture is simpler than that of the conventional analog parallel processing structure with the similar decoding performance. Characteristics of the feed forward differential architecture are investigated through various simulation studies.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.2
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• pp.138-145
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• 2010

In this paper, we consider the information processing system, which organizes the collected data to meaningful information when the number of data collected from multiple sources reaches to a predetermined number, and performs any action by processing the collected data, or transmits to other devices or systems. We derive an analytical model to calculate the time until it takes to process information after starting to collect data. Therefore, in order to complete the processing data within certain time constraints, we develop some design criteria to control various parameters of the information processing system. Also, we analyze the discrete time model for packet switching networks considering data with no particular arrival nor drop pattern. We analyze the relationship between the number of required packets and average information processing time through numerical examples. By this, we show that the proposed model is able to design the system to be suitable for user's requirements being complementary the quality of information and the information processing time in the system with time constraints.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.11-15
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• 2015

In this study, we present the architecture design of data control system in water hazard information platform with analyzing the complexity of the data processing. Generally, data control systems in data collection and analysis platforms base on the constant data-algorithm data processing meaning that data processing between data and algorithm is fixed. But the number of data processing in data control system is rapidly increasing because of increasing of complexity of system. To hold down the number of data processing, dynamic data-algorithm data processing is able to be applied to data control system. After comparison each data-algorithm data processing method, we suggest design method of the data control system optimizing water hazard information platform.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.137-142
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• 2017

Recently, along with the development of IoT technology, technologies for wirelessly sensing various data, such as sensor nodes, RFID, CCTV, smart phones, etc., have rapidly developed, and in the field of multiple applications, to utilize sensor network related technology Have been actively pursued in various fields. Therefore, as GeoSensor utilization increases, query processing systems for efficiently processing 2D data such as spatial sensor data are actively researched. However, existing spatial query processing systems do not support a spatial-temporal data type and a spatial-temporal operator for processing spatial-temporal sensor data. Therefore, they are inadequate for processing spatial-temporal sensor data like GeoSensor. Accordingly, this paper developed a spatial-temporal query processing system, for efficient spatial-temporal query processing of spatial-temporal sensor data in a sensor network.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.9
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• pp.839-844
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• 2017

In the past few years, three-dimensional (3D) printing has been developed as a rapid prototyping (RP) technique. The fused deposition modeling (FDM)-type 3D printing is one of the most useful RP methods; however, it still has several disadvantages, such as low conductivity, heat degradation, and low surface quality. In this study, test specimens are fabricated using an FDM-type 3D printer with an ABS material. Then, the specimens undergo post-processing on submerging in acetone with various processing times. As the processing time increases, surface roughness is enhanced significantly within the first five seconds by chemical processing, following which the processing effects are reduced. Furthermore, post processing causes the ultimate strength and strain to increase slightly with increased processing time.

• Journal of the Korean Home Economics Association
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• v.46 no.9
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• pp.125-135
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• 2008

The purpose of this study was to examine the effects of young children's age and information processing style in understanding spatial coordinates. For sampling the subjects of this study, Korean version K-ABC Intelligence Test(Moon, Soo-Back, 1997)was conducted with 165 children aged 5-6 who were attending I and G kindergarten in D city. From this pool 30 children who possessed sequential processing style and 30 children who possessed simultaneous processing style were sampled. In order to analyze the understanding of spatial coordinates, a test tool was formulated according to methodology of Blades & Spencer(1989) which was modified. Acquired data was subjected to descriptive and comparative statistical analysis. The following conclusions were arrived at: Firstly, there was significant difference between 5-year-olds and 6-year-olds in understanding spatial coordinates. The 6-year-old group got statistically higher grades than the 5-year-old group in locating a point on the coordinate plane and reading the coordinate numbers. Secondly, there was significant difference between children's information processing style in understanding spatial coordinate. Children with high simultaneous-low sequential processing showed higher performance in locating a point on the coordinate plane and reading coordinate numbers than children with high sequential-low simultaneous processing. Thirdly, after verifying statistical significance of interactivity between young children's age and children's processing strength, there was significant interactive effects in both tasks.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.1
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• pp.87-98
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• 2016

A single machine scheduling problem for jobs with stochastic processing time is considered in this study. Shortest processing time (SPT) sequencing according to the expected processing times of jobs is optimal for schedules with minimal expected mean flow time when all the jobs arrive to be scheduled and their expected processing times are known. However, SPT sequencing according to the expected processing time may not be optimal for the minimization of the mean flow time when the actual processing times of jobs are known. This study evaluates the complexity of SPT sequencing through a comparison of the mean flow times of schedules based on the expected processing times and actual processing times of randomly generated jobs. Evaluation results show that SPT sequencing according to the expected flow time exhibits chaotic variation to the optimal mean flow time. The relative deviation from the optimal mean flow time increases as the number of jobs, processing time, or coefficient of variation increases.

• The Journal of the Acoustical Society of Korea
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• v.31 no.6
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• pp.384-390
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• 2012

Passive sonars employ DEMON(Detection of Envelope Modulation on Noise) processing to extract propeller information from the radiated noise of underwater targets. However, the conventional DEMON processing suffers from the interference of tonal signals because it extracts propeller signals and some types of tonal signals as well. If there are some tonals in the frequency band for DEMON processing, the conventional DEMON processing may additionally extract frequency informations originated from the interaction between different tonals. In this paper, we propose a modified DEMON processing, which can eliminate the interference of the tonals. The proposed algorithm removes tonals in DEMON processing band before demodulation processing, hence results the robustness to the interference of the tonals. Some numerical simulations demonstrate the improved performance of the proposed algorithm against the conventional algorithm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.2
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• pp.251-254
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• 2014

In this paper, we studied a technique of extracting a Frequency Hopping(FH) signal for analysis using high-speed parallel processing structure. Unlike fixed frequency signal, FH signal is difficult to detect and analyze because FH systems use many random frequencies instead of a single carrier frequency. To solve this problem we designed a method that analyze FH signal using high-speed parallel processing. In order to apply parallel processing, we use CUDA using GPU and compare single processing with prarallel processing. As a result, using CUDA on a GPU is about 8.53 times faster than single processing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1100-1105
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• 2000

The most widely used radar pulse compression technique is correlation processing using Barker code. This technique enhances detection sensitivity but, unfortunately, suffers from the addition of range sidelobes which sometimes will degrade the performance of radar systems. In this paper, our proposed optimal algorithm eliminates the sidelobes at the cost of additional processing and is evaluated in the presence of Doppler shift. We then propose optimal codes with regard to the proposed algorithm and the performance is compared against the traditional correlation processing with Barker codes. The proposed processing using optimal codes will be shown to be superior over the traditional processing in the presence of Doppler shift.