• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.2987-3002
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• 2013

The problem of optimal channel sensing in heterogeneous cognitive networks is considered to maximize the system throughput performance. The characteristics of an optimal operating sensing point maximizing the overall system rate are investigated under several rate criteria including the sum rate, the minimum of the primary and secondary rates, and the secondary rate with a guaranteed primary rate. Under the sum rate criterion, it is shown that the loss by imperfect sensing is no greater than half of the sum rate achieved by the perfect time sharing approach in a two user case if the sensing point is optimally designed.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.25-30
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• 1999

This paper covers the development of a highly portable and low cost SPOT image data receiving system. We followed two design approaches. One is the software-based approach by which most of the real-time processing is handled by software. With the complete software-based design, it is simple to add a function for receiving any additional satellite data. Satellite-specific format handlers including error correction, decompression and decryption can easily be accommodated. On the other approach. we used a general hardware platform, IBM-PC and a low cost SCSI RAID (Redundant Away of Independent Disks), and therefore, we can make a low cost system.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.355-360
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• 2022

In this paper, we present design and developing method for EMS(environment monitoring system) of micro data center. This developing EMS monitors operating environment of micro data center and analyze sensing data through IoT(Internet of things) sensors in real time. Firstly we present configuration method of IoT sensing package and design method EMS hardware platform. Secondly we design data collector software for data collection of IoT sensor with different protocol and develop monitoring software of EMS. The data collector software consists of sensor collector module and collector manager module. Also we design EMS software which has micro service architecture structural style and component based business logic.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.43-47
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• 1999

In this paper, we describe the configuration of the KITSAT-3 image data receiving, archiving, processing and distribution system in operation. Following the low-cost and software-based design concept, the whole system is composed of three PCs : two for data receiving, archiving and processing which provide a full dual-redundant configuration and one for image catalog browsing which can be accessed by public users. Except that receiving and archiving PCs have serial data ingest boards plugged in, they are configured by general peripherals. This basic and simple hardware configuration made it possible to show that a very low cost system can support a full ground operation for the utilization of high-resolution satellite image data.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.134-145
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• 1998

The purpose of this paper is to construct a computer simulation system which can analyze and design the hydraulic excavator Theoretical analyses are performed on the hydraulic circuit and attachment of excavator with load sensing system. Databases are constructed for control valve opening areas, horsepower control and for load sensing regulator. For hydraulic components modularized programming techniques are applied which is expected to be utilized for software development of fluid power system. Through simulation an information of any point in hydraulic circuit can be obtained.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.961-964
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• 2012

This paper presents a sensing system to measure the deflection of a microcantilever in an atomic force microscope. In general, the optical lever method and interferometry are used for the sensing system; however, their size and cost leaves considerable room for improvement. Therefore, we used an optical pickup head whose operating principle is based on the astigmatism of the commercial optical disk drives. The developed sensing system was applied to a laboratory atomic force microscope, and satisfactory results were obtained.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.88-99
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• 1998

In assembly, misalignment must be detected and compensated for during the mating period, regardless of the complexity of the cross-sectional shape. To this end, we propose a novel omnidirectional image sensing system for assembling parts with complicated shapes(OISSA) and its feasibility for detecting the misalignment between mating parts is shown by a series of simulations. This system encompasses a camera with an optical unit attached to the front of the camera. The optical unit consists of a pair of plane mirrors and a pair of conic mirrors. Utilizing the proposed sensing system, a 2$\pi$ coaxial image of the misalignment along the mating boundary interface between mating parts can be immediately obtained without experiencing self-occlusion.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.942-947
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• 2003

An important signal processing problem in PVDF sensor is the restoration of surface information from electric sensing signals. The objectives of this research are to design a new texture sensing system and to develop a new signal processing algorithm for signals from the sensor to be tangibly displayed by tangible interface systems. The texture sensing system is designed to get surface information with high resolution and dynamic range. First, a PVDF sensor is made of piezoelectric polymer (polyvinylidene fluoride) strips molded in a silicon rubber and attached in a rigid cylinder body. The sensor is mounted to a scanning system for dynamic sensing. Secondly, a new signal processing algorithm is developed to restore surface information. The algorithm consists of the two-dimensional modeling of the sensor using an identification method and inverse filtering from sensing signals into estimated surface information. Finally the two-dimensional surface information can be experimentally reconstructed from sensing signals using the developed signal processing algorithm.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.763-765
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• 2005

In the area of remote sensing, an immense number of images are continuously generated by various remote sensing systems. These images must then be managed by a database system efficient storage and retrieval. There are many types of image database systems, among which the content-based image retrieval (CBIR) system is the most advanced. CBIR utilizes the metadata of images including the feature data for indexing and searching images. Therefore, the performance of image retrieval is significantly affected by the storage method of the image metadata. There are many features of images such as color, texture, and shape. We mainly consider the shape feature because shape can be identified in any remote sensing while color does not always necessarily appear in some remote sensing. In this paper, we propose a metadata representation and storage method for image search based on shape features. First, we extend MPEG-7 to describe the shape features which are not defined in the MPEG-7 standard. Second, we design a storage schema for storing images and their metadata in a relational database system. Then, we propose an efficient storage method for managing the shape feature data using a Wavelet technique. Finally, we provide the performance results of our proposed storage method.

• The Journal of the Acoustical Society of Korea
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• v.38 no.5
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• pp.522-533
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• 2019

The compressive sensing model for range-Doppler estimation can be expressed as an under-determined linear system y = Ax. To find the solution of the linear system with the compressive sensing method, matrix A should be sufficiently incoherent and x to be sparse. In this paper, we propose a transmission waveform design method that maintains the bandwidth required by the sonar system while lowering the mutual coherence of the matrix A so that the matrix A is incoherent. The proposed method combines two methods of optimizing the sensing matrix with the alternating projection and suppressing unwanted frequency bands using the DFT (Discrete Fourier Transform) matrix. We compare range-Doppler estimation performance of existing waveform LFM(Linear Frequency Modulated) and designed waveform using the matched filter and the compressive sensing method. Simulation shows that the designed transmission waveform has better detection performance than the existing waveform LFM.