• The Journal of Korean Institute of Communications and Information Sciences
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• 제38C권5호
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• pp.434-439
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• 2013

It is very difficult to monitor the blind spots that are not recognized by traditional surveillance camera (CCTV) systems, and the surveillance efficiencies are very low though many accidents/events can be solved by the systems. In this paper, the fuzzy logic based sound source localization system using sound strength in the underground parking lot is suggested and the performance of the system is analyzed in order to enhance the stabilization and the accuracy of the localization algorithm in the suggested system. It is confirmed that the localization stabilization of the localization algorithm (SLA_fuzzy) using the fuzzy logic in the suggested system is 4 times higher than that of the conventional localization algorithm (SLA). In addition to this, the localization accuracy of the SLA_fuzzy in the suggested system is 29% higher than that of the SLA.

• Journal of the Institute of Electronics Engineers of Korea CI
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• 제46권5호
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• pp.29-36
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• 2009

Cost and Time for software test is gradually increasing as the software complexity increases. To cope with this problem, it is very important to reduce the number of test cases used in the software test. The interaction strength number is especially important in decision of the number of test cases for the unit test, where the interaction strength number means the number of arguments which affect the results of a function by the analysis of their combination used in source code of the function. This paper proposes the algorithm that computes the number of the interaction strength, where analyzes the patterns used in the source code of a function and increase its number when the pattern matches one of the specified patterns. The proposed algorithm is validated by some experiments finding coverage and the number of fault detection.

• Korean Journal of Materials Research
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• 제17권10호
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• pp.509-515
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• 2007

In order to fabricate adhesiveless 2-layer flexible copper clad laminate (FCCL) used for COF (chip on film) with high peel strength, polyimide (PI; Kapton-EN, $38\;{\mu}m$) surface was modified by reactive $O_2^+$ and $N_2O^+$ ion beam irradiation. 300 mm-long linear electron-Hall drift ion source was used for ion irradiation with ion current density (J) higher than $0.5\;mA/cm^2$ and energy lower than 200 eV. By vacuum web coating process, PI surface was modified by linear ion source and then 10-20 nm thick Ni-Cr and 200 nm thick Cu film were in-situ sputtered as a tie layer and seed layer, respectively. Above this sputtered layer, another $8-9{\mu}m$ thick Cu layer was grown by electroplating and subsequently acid and base resistance and thermal stability were tested for examining the change of peel strength. Peel strength for the FCCLs treated by both $O_2^+$ and $N_2O^+$ ion irradiation showed similar magnitudes and increased as the thickness of tie layer increased. FCCL with Cu (200 nm)/Ni-Cr (20 nm)/PI structure irradiated with $N_2O^+$ at $1{\times}10^{16}/cm^2$ ion fluence was proved to have a strong peel strength of 0.73 kgf/cm for as-received and 0.34 kgf/cm after thermal test.

• Journal of the Korea Institute of Building Construction
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• 제5권1호
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• pp.123-129
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• 2005

This study is as a part of the new disposal and recycling plans of heat-resource waste of Daegu dyeing industrial center we tried to examine applicable possibility of crushed thing(waste aggregate) as aggregates for mortar and concrete. To examine applicable possibility of waste aggregate as a lightweight-aggregate for concrete and mortar, we carried this study by mainly property examination of concrete according to replacement ratio of waste aggregate. We carried slump, unit weight, compressive strength and bending strength test according to replacement ratio of waste aggregate. As the result of that, if we use waste aggregate, lightweight of concrete and mortar will be possible. Specially it shows a strength improvement effect of cement hardening according to using this so it is judged that applicable possibility as aggregate for concrete and mortar is very excellent.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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• pp.99-104
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• 2005

This study is as a part of the new disposal and recycling plans of heat-resource waste of Daegu dyeing, industrial center we tried to examine applicable possibility of crushed thing(waste aggregate) as aggregates for mortar and concrete. To examine applicable possibility of waste aggregate as a lightweight-aggregate for concrete and mortar, we carried this study by mainly property examination of concrete according to replacement ratio of waste aggregate. We carried slump, unit weight, compressive strength and bending strength test according to replacement ratio of waste aggregate. As the result of that, if we use waste aggregate, lightweight of concrete and mortar will be possible. Specially it shows a strength improvement effect of cement hardening according to using this so it is judged that applicable possibility as aggregate for concrete and mortar is very excellent.

• Progress in Medical Physics
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• 제15권4호
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• pp.192-196
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• 2004

The activity of Ir-192 sources for high dose rate (HDR) Brachytherapy in Korea were measured by using the well-type chamber and using the calibration Jig with the Farmer-type ionization chamber to compare the manufacturer certificated source strength which is supplied with each new Ir-192 source. The activity of two different source models used in six hospitals were measured. The range of measured activities to the manufacturer's suggested ones was -2.40% to +3.31% for the calibration Jig and -3.12% to 0.00% for the well-type chamber system. The source strength values given by the manufacturer for the 6 sources were within ${\pm}5%$ for the two different measuring equipment. Our results demonstrate that well-type chamber as wall as Farmer-type chamber system are appropriate system for the routine source calibration procedures in HDR brachytherapy. Whenever a new source is installed to use in clinics, a source calibration should be carried out.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.279-284
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• 2007

The cultural noise sources in magnetotellurics were localized using the source localization method. Conventional beamforming techniques are not applicable for electromagnetic source localization. In this study, the matched field processing and genetic algorithm are used to localize an electromagnetic source and estimate the polarization direction. The source localization using MT field data shows the characteristics of estimated source distribution related to the strength of cultural noise.

• Journal of the Korean Geotechnical Society
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• 제32권5호
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• pp.5-13
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• 2016

A calcium source is necessary for calcite precipitation within soil particles by microbial decomposition of urea and a calcium chloride is usually used. The harmful environmental impact of calcium chloride on road, ground and plants is severe. In this study, an eggshell with vinegar is investigated for an environmental-friendly calcium source. Urea-decomposing microorganism and eggshell or calcium chloride as a calcium source are mixed with Ottawa sand to precipitate calcite. Then, the cemented sand with calcite is tested for calcite precipitation, permeability and unconfined compressive strength. A specimen is prepared by loose Ottawa sand in a size of 5 cm in diameter and 10 cm in height. A urea solution with Sporosarcina pasteurii and two different calcium sources is injected into the specimen once a day for 30 days. Calcite precipitated at average of 7.2% on the specimen with eggshell as a calcium source, which was 1.2 times more than that with calcium chloride. The permeability of a specimen with eggshell was at average of 3.82E-5 cm/s, which was 7.7 times lower than that with calcium chloride. Unconfined compressive strength of a specimen with eggshell was at average of 387 kPa, which was 1.2 times higher than that with calcium chloride. As more calcite precipitated, the strength increased while the permeability decreased, regardless of calcium sources.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.206-221
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• 2019

Source localization in three-dimensional (3-D) wireless sensor networks (WSNs) is becoming a major research focus. Due to the complicated air-ground environments in 3-D positioning, many of the traditional localization methods, such as received signal strength (RSS) may have relatively poor accuracy performance. Benefit from prior learning mechanisms, fingerprinting-based localization methods are less sensitive to complex conditions and can provide relatively accurate localization performance. However, fingerprinting-based methods require training data at each grid point for constructing the fingerprint database, the overhead of which is very high, particularly for 3-D localization. Also, some of measured data may be unavailable due to the interference of a complicated environment. In this paper, we propose an efficient kernel based 3-D localization algorithm via tensor completion. We first exploit the spatial correlation of the RSS data and demonstrate the low rank property of the RSS data matrix. Based on this, a new training scheme is proposed that uses tensor completion to recover the missing data of the fingerprint database. Finally, we propose a kernel based learning technique in the matching phase to improve the sensitivity and accuracy in the final source position estimation. Simulation results show that our new method can effectively eliminate the impairment caused by incomplete sensing data to improve the localization performance.

• The Journal of the Acoustical Society of Korea
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• 제24권3호
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• pp.166-170
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• 2005

This paper describes the experimental study for the position estimation method of underwater sound source using the Nearfield Acoustic Holography. The result confirms that it can be used in the identification of underwater noise sources. The sound sources in the experimental work consists of 2 spherical projectors and the near-Held sound pressure is measured in the hologram plane. From the cross-power spectra of the measured data, the complex sound pressures on the hologram plane is derived and its spatial transformation gives sound fields in a source region. The obtained sound fields in a source region showed that the position of each sound source and their relative source strength are exactly estimated. In conclusion, this technique can be applied for estimation of each source position and its relative strength contribution for the underwater multiple sound sources.