• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.11
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• pp.919-927
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• 2013

In this paper, we present a perception-based tone mapping technique using histogram modification for displaying high dynamic range image. HDR (high dynamic range) tone mapping algorithms are used to display HDR image on LDR (low dynamic rnage) devices. Although perception-based tone mapping methods provides better performance, it dose not always produce good results for a wide variety of images. The proposed method reduces dynamic range by using the perception-based tone mapping function and histogram modification. A derivative of perception-based tone mapping function is used as constraint function of histogram and additional compensation process is performed. This method not only improves contrast by adopting different constraints on each pixel value, but also preserves more visual details. In order to prevent over enhancement, histogram modification technique is applied. Furthermore, it can control the rate of image contrast using control parameters. Subjective and objective evaluations show that proposed algorithm is better than existing algorithms.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.6
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• pp.397-401
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• 2007

Recent applications on continuous queries on moving objects are extended quickly to various parts. These applications need not only 2-dimensional space data but also high-dimensional space data. If we use previous index for overlapped continuous range queries on high-dimensional space data, as the number of continuous range queries on a large number of moving objects becomes larger, their performance degrades significantly. We focus on stationary queries, non-exponential increase of storage cost and efficient processing time for large data sets. In this paper, to solve these problems, we present a novel query indexing method, denoted as PAB(Projected Attribute Bit)-based query index. We transfer information of high-dimensional continuous range query on each axis into one-dimensional bit lists by projecting technique. Also proposed query index supports incremental update for efficient query processing. Through various experiments, we show that our method outperforms the CES(containment-encoded squares)-based indexing method which is one of the most recent research.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.12
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• pp.1049-1055
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• 2007

Lots of integration work has been done in order to miniaturize the devices for communication. To do this work, one of key work is to get miniaturized inductor with high Q factor for RF circuitry. However, it is not easy to get high Q inductor with silicon based substrate in the range of GHz. Although silicon is well known for its good electrical and mechanical characteristics, silicon has many losses due to small resistivity and high permittivity in the range of high frequency. MEMS technology is a key technology to fabricate miniaturized devices and LTCC is one of good substrate materials in the range of high frequency due to its characteristics of high resistivity and low permittivity. Therefore, we proposed and studied to fabricate and analyze the inductor on the LTCC substrate with MEMS fabrication technology as the one of solutions to overcome this problem. We succeeded in fabricating and characterizing the high Q inductor on the LTCC substrate and then compared and analyzed the results of this inductor with that on a silicon and a glass substrate. The inductor on the LTCC substrate has larger Q factor value and inductance value than that on a silicon and a glass substrate. The values of Q factor with the LTCC substrate are 12 at 3 GHz, 33 at 6 GHz, 51 at 7 GHz and the values of inductance is 1.8, 1.5, 0.6 nH in the range of 5 GHz on the silicon, glass, and LTCC substrate, respectively.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.539-543
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• 2005

The research presented in this paper enables real-time 3D modeling to help make construction processes ultimately faster, more predictable and safer. Initial research efforts used an emerging sensor technology and proved its usefulness in the acquisition of range information for the detection and efficient representation of static and moving objects. Based on the time-of-flight principle, the sensor acquires range and intensity information of each image pixel within the entire sensor's field-of-view in real-time with frequencies of up to 30 Hz. However, real-time working range data processing algorithms need to be developed to rapidly process range information into meaningful 3D computer models. This research ultimately focuses on the application of safer heavy equipment operation. The paper compares (a) a previous research effort in convex hull modeling using sparse range point clouds from a single laser beam range finder, to (b) high-frame rate update Flash LADAR (Laser Detection and Ranging) scanning for complete scene modeling. The presented research will demonstrate if the FlashLADAR technology can play an important role in real-time modeling of infrastructure assets in the near future.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.52-59
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• 2007

Telecommunication satellite consists of a bus system and an RF payload system with high efficiency and high gain reflector antennas. Antenna measurement and also RF system performance (antenna under test, payload and satellite level) have to be evaluated enough before launching in the far-field range or equivalent test range. Basically far-field range is required in a range from two hundred meters to several kilo meters, and it is highly constrained to the externa1 environment, like the RF and the whether environment So the compact antenna test range is developed and used efficiently without external environments as in-door facility. This paper describes the configuration of the compact antenna test range, the range error, and the physical concept of the plane wave illumination Also, it provides a overall design of the anechoic chamber and range parameter values to accommodate the precision measurements in antenna test range.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.9
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• pp.321-326
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• 2015

In this paper, we proposed an algorithm which could transmit reliable data between smart devices by using inaudible high frequency of audible frequency range and cyclic redundancy check method. The proposed method uses 18 kHz~22 kHz as high frequency which inner speaker of smart device can make a sound in audible frequency range (20 Hz~22 kHz). To increase transmission quantity of data, we send mixed various frequencies at high frequency range 1 (18.0 kHz~21.2 kHz). At the same time, to increase accuracy of transmission data, we send some mixed frequencies at high frequency range 2 (21.2 kHz~22.0 kHz) as checksum. We did experiments about data transmission between smart devices by using the proposed method to confirm data transmission speed and accuracy of the proposed method. From the experiments, we showed that the proposed method could transmit 32 bits data in 235 ms, the transmission success rate was 99.47%, and error detection by using cyclic redundancy check was 0.53%. Therefore, the proposed method will be a useful for wireless transmission technology between smart devices.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.920-928
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• 2016

Recently high dynamic range imaging technique is hot issue in computer graphic area. We present a progressive tone mapping algorithm, which is based on weighted least squares optimization framework. Our approach combines weighted least squares filtering with iCAM06 model. To show more perceptual high dynamic range images in conventional display, we decompose high dynamic range image into base layers and detail layers. The base layers are obtained by using weighted least squares filter. Then, we adopt chromatic adaption function and non-linear compression function to deal with base layers. Only the base layers reduce contrast, and preserving detail. The image quality assessment shows that our tone mapped image is more similar to original high dynamic range image. Moreover, the subjective result shows our algorithm produces more reliable and pleasing image.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.101-103
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• 2012

Characteristic of aluminum ignition under high temperature and high pressure is studied using lasers. The laser ablation method is used to generate aluminum particles exposed to a high pressure by using a nanosecond pulsed laser where the range of ablation pressure varies between 0.35 and 2.2 GPa. A $CO_2$ laser is used to supply radiative heat to the aluminum target surface for providing high temperature ranging between 5000~9300 Kelvin. The ignition is confirmed using spectroscopy analysis of AlO vibronic band 484 nm wavelength. Also the radiative temperature is measured in various high pressure range for tracing the ignition temperature in high pressure conditions.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.26-29
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• 1987

This paper concerns methods for ${\mu}$-wave imaging. The image reconstruction of an object by range-doppler preceding using the X-Band Linear-FM signal is presented from tile simulated data. The high degree of range resolution is achived using large signal band width and cross-range resolution is obtained by doppler processing.

• Journal of the Korean Institute of Telematics and Electronics
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• v.9 no.5
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• pp.27-33
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• 1972

This paper describes the computer-aided design, fabrication and performance of high Q and high gain active filters suitable for microminiaturization in the frequency range of 10-800MHz, based on the negative resistance operation of a transistor. 48 as high as 1000 and a transducer gain as high as 35dB can readily be obtained with a single-transistor amplifier and with an inductance as small as a few nH at higher frequencies and 150 nH at lower frequencies in tile above frequency range. The gain of the proposed active filter can be stoabilized within $\pm$ 1.5 dB over the temperature range -1$0^{\circ}C$ to +5$0^{\circ}C$ and the temperature dependence of the center frequency is tapicalla 50ppm/$^{\circ}C$. An experimental FM receiver utilizing these fitters and operating at a carrier frequency of 92 MH3 was built. The whole circuit was fabricated on eight alumina substrates of by the thick-film hybrid IC technique and the coils are constructed, for miniaturization, in a spiral form of 3 or 4 turns of enamel copper wire with an overall diameter of about 5mm. The test results are also reported in this paper.