• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.4 s.97
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• pp.382-387
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• 2005

For successful guided-wave damage inspection, the appropriate signal processing of measured wave signals is very important. The objective of this paper is to introduce an efficient signal processing technique especially suitable for the guided-waves used for damage detection. The key idea of this technique is to model guided-waves by chirp functions of special form considering the dispersion phenomenon. To determine the parameter of the chirp functions simulating guided-waves, the matching pursuit algorithm is employed. The damage information in waveguides can be extracted by pulse-characterizing parameters. The effectiveness of present method is checked with the guided wave-based damage inspection.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.7
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• pp.1039-1046
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• 2001

Among the automotive steering systems, an Electric Power Assisted steering (EPAS) system utilizes an electronically controlled electric motor to provide steering assistance to the driver. The key components of the EPAS system are torque sensor, ECU (Electronic Control Unit), and DC Motor. The most important component of the EPAS is the torque sensor. The conventional torque sensor has complicated mechanical mechanism of torque detection. However, we suggest a non-contact torque sensor for EPAS using Maluss polarization law. It was found that the sensor exhibited not only excellent linearity but also superior characteristics of hysteresis, temperature and vibration.

• Journal of Computing Science and Engineering
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• v.5 no.1
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• pp.71-84
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• 2011

Pervasive applications such as digital memories or patient monitors collect a vast amount of data. One key challenge in these systems is how to extract interesting or unusual information. Because users cannot anticipate their future interests in the data when the data is stored, it is hard to provide appropriate indexes. As location-tracking technologies, such as global positioning system, have become ubiquitous, digital cameras or other pervasive systems record location information along with the data. In this paper, we present an automatic approach to identify unusual data using location information. Given the location information, our system identifies unusual days, that is, days with unusual mobility patterns. We evaluated our detection system using a real wireless trace, collected at wireless access points, and demonstrated its capabilities. Using our system, we were able to identify days when mobility patterns changed and differentiate days when a user followed a regular pattern from the rest. We also discovered general mobility characteristics. For example, most users had one or more repeating mobility patterns, and repeating mobility patterns did not depend on certain days of the week, except that weekends were different from weekdays.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.122-130
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• 2012

Airborne separation assurance is a key requirement for Free Flight. This paper is to propose autonomous flight algorithm, such as extended authority of delegation, efficiency of airspace issue to deal with the empirical solution for free flight, and to measure flight efficiency and conflict detection and resolution (CD&R) by utilizing flight performance data under the two circumstances of scenario with the modeling of proposed algorithm and potential field algorithm. The results show that the autonomous flight algorithm is superior to the potential field algorithm under the circumstances of free flight airspace in terms of algorithm performance, CD&R, and flight efficiency.

• Korean Journal of Microbiology
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• v.11 no.2
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• pp.63-68
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• 1973

Thirtythree strains of the Aspergillus spp. isolated from foodstuffs were observed through some physiological characteristics for detection of identification key of Aspergillus spp. 1) Each strain of Aspergillus spp. had their specific characteristics and could be used for identification of species. 2) Excellent amylase-producing fungi were observed among the isolated strains of Aspergillus spp. 3) Amylase activities increased for one week incubation period. 4) In the tests of common characters of aflatoxin-producing fungi among the 33 strains of Aspergillus spp., for example, conidial size, presence of sclerotia, kojic acid, and pigment production, coloration of phenol, reduction of methylene blue, etc.

• Journal of information and communication convergence engineering
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• v.18 no.1
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• pp.28-32
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• 2020

Railway transportation is the main land-based transportation in most countries. Accordingly, railway-transportation safety has always been a key issue for many researchers. Railway pedestrian accidents are the main reasons of railway-transportation casualties. In this study, we conduct experiments to determine which of the latest convolutional neural network models and algorithms are appropriate to build pedestrian railroad accident prevention systems. When a drone cruises over a pre-specified path and altitude, the real-time status around the rail is recorded, following which the image information is transmitted back to the server in time. Subsequently, the images are analyzed to determine whether pedestrians are present around the railroads, and a speed-deceleration order is immediately sent to the train driver, resulting in a reduction of the instances of pedestrian railroad accidents. This is the first part of an envisioned drone-based intelligent security system. This system can effectively address the problem of insufficient manual police force.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.512-514
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• 1998

샷 경계면 분할 기법은 효과적인 비디오 검색 시스템을 구축하기 위한 기본적인 기술이다. 따라서 효과적인 비디오 분석을 위해서는 신뢰할만한 샷 경계면 검출 기술이 필요하다. 하지만 비디오에서는 일반적인 프레임 뿐만 아니라 디졸브, 페이드와 같은 다양한 형태의 특수효과 등이 포함되어 있어 포괄적인 기술 개발이 어렵다. 본 논문에서는 지금까지 알려진 몇 가지 기법들의 성능을 비교하고 이를 개선시켜 몇 개의 새로운 알고리즘을 제안하고 있다. 샷 경계면 분할 작업이 끝난 뒤에는 비디오 클러스터링을 하기 위한 대표프레임 추출 작업이 필요하다. 대표 프레임은 단순하게 각 샷의 첫 번째 혹은 마지막 프레임을 추출할 수도 있지만, 이 경우 각 샷의 동적인 특성들을 제대로 표현할 수 없으므로, 본 논문에서는 샷의 변화량을 측정하여 대표 프레임의 수를 결정하는 방법을 사용하였다.

• Annual Conference of KIPS
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• 2005.05a
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• pp.793-796
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• 2005

금형공장의 생산 일정관리에 있어서 실제 가공작업에 대한 실적데이터의 집계는 매우 중요하지만, 이러한 작업상황을 기록하는 것에 대해서 현장 작업자는 비협조적이고 반감을 갖고 있는 실정이다. 현장에서는 작업자의 개입없이 CNC 장비의 컨트롤러와의 직접적인 인터페이스를 통해서 신호를 추출하고 자동으로 작업상황을 파악할 수 있는 시스템을 구축하려고 시도하고 있지만, 컨트롤러 메이커마다 다르게 적용해야 하고 많은 비용을 요구한다. 이러한 이유로 본 연구에서는 저가의 PC 카메라를 장비에 설치하여 가공상황에 대한 동영상을 수집하고 영상처리 알고리즘을 적용하여 가공시간을 집계하는 방법을 제안한다. 제안된 방법은 CNC 컨트롤러에 독립적으로 운용되며 저렴하게 시스템을 구축할 수 있는 장점이 있다. 본 연구에서는 무인가공과 유인가공 상황에 시범적으로 적용 및 운영함으로써 시스템의 활용가능성을 살펴보았다.

• Clinical and Experimental Pediatrics
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• v.53 no.12
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• pp.985-988
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• 2010

The innate immune response is the first line of defense against microbial infections. Innate immunity is made up of the surface barrier, cellular immunity and humoral immunity. In newborn, immunologic function and demands are different to adults. Neonatal innate immunity specifically suppresses Th1-type immune responses, and not Th2-type immune responses, which are enhanced. And the impaired response of macrophages is associated with the defective innate immunity in newborn period. Toll-like receptors (TLRs) play a key roles in the detection of invading pathogens and in the induction of innate immune responses. In newborn, the expression of TLRs is age dependent, so preterm has low expression of TLRs. Also, there are defects in signaling pathways downstream of TLRs. As a consequence, the defects of TLRs activity cause the susceptibility to infection in the neonatal period.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.607-612
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• 2005

Check valves playa vital role in the operation and protection of nuclear power plants. Check valves failure in nuclear power plants often lead to a plant transient or trip. An overview of the failure history of check valves needs to identify key area where resources can be best applied to further improve their reliability, and provide cost effective means for failure reduction. The analysis of historical failure data gives information on the populations of various types of check valves, the systems they are installed in, failure modes, effects, methods of detection, and the mechanisms of the failures. The results presented are based on information derived from operating records, nuclear industry reports, manufacturer supplied information. A majority of check valve failures are caused by improper application. Failure modes are identified for swing and lift check valves. Failures involving improper seating and valve disc stuck comprised the largest percentage of failures.