• 대한한방내과학회지
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• 제28권1호
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• pp.97-105
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• 2007

Objectives : This study investigated the correlation between dry mouth and comprehensive diagnosis of Qi xu and Qi yu in patients with halitosis. Methods : We surveyed 124 halitosis patients by reviewing the questionnaires from the Halitosis Clinic in the Hospital of Oriental Medicine, Kyunghee University from January 2004 to March 2006. The halitosis questionnaires contained self-awareness of halitosis, self-assessed severity of halitosis, dry mouth and taste abnormality. Among comprehensive diagnosis of Qui Xue Shui, Qi xu and Qi yu parts were investigated by questionnaire and physical examination, and each Qi xu and Qi yu part scores were summed. Winkel tongue coating index was estimated by investigator, the level of volatile sulfur compounds were measured by halimeter, and salivary function was assessed by salivary scan test. All patients were divided into two groups based on salivary scan test (salivary function normal and decreased). Results : Qi xu score of halitosis patients with decreased salivary function was higher than normal halitosis patients. There was highly significant correlation between Qi yu score and dry mouth, and another significant correlation between self-assessed halitosis severity and dry mouth was noted. Conclusions : The results of this study suggest that Qi yu condition influences dry mouth in halitosis patients, and halitosis is affected by dry mouth. Therefore. we assume that treating Qi yu condition can be a potentially effective way of treating dry mouth and halitosis.

• 한국터널지하공간학회 논문집
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• 제25권4호
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• pp.331-344
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• 2023

본 논문은 일본의 성능평가 제도인 NETIS의 사후평가와 점검 지원 기술 성능 카탈로그를 통해 기존 터널 스캐닝 시스템의 성능을 분석하였다. 분석을 통해 터널 스캐닝 시스템의 개선 사항과 개발 방향에 대한 시사점을 도출하였다. 일본의 신기술은 사용자 중심의 정보 제공을 우선시하여 NETIS의 사후평가와 점검 지원 기술 성능 카탈로그의 표준시험방법을 통해 다양한 터널 스캐닝 시스템의 특성을 객관적으로 비교하고 분석할 수 있다. 국내의 건설신기술은 기술인증의 공급자 중심으로 터널 스캐닝 시스템에 대한 객관적인 성능 비교는 불가능하였다. 일본의 터널 스캐닝 시스템의 핵심장치인 카메라의 제원을 비교하여 성능을 간접적으로 비교 평가하였다. 향후 터널 스캐닝 시스템 개발을 위해서는 카메라의 고해상도와 빠른 노출 성능 그리고 이에 부합되는 고휘도의 조명 장치가 요구된다. 실내에서 카메라와 조명의 성능을 분석할 수 있는 실험 환경 조성도 필요할 것으로 판단된다.

• 한국건설관리학회논문집
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• 제17권3호
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• pp.32-42
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• 2016

현재 국내 대부분의 토목 건축 구조물이 BIM 정보가 부재한 상황에서 준공 BIM(as-built BIM)의 수요가 점차 증가하고 있다. 준공 BIM 구축을 위한 공간자료 취득에는 고밀도의 포인트 클라우드를 생성할 수 있는 레이저 스캐너가 주로 활용되고 있다. 하지만 기존의 고정식 스캔 시스템은 이동이 번거롭고, 정밀한 위치 선정이 필요 하며, 스캔 자료 정합을 위해 별도의 표지를 설치하거나 공액점을 추출하는 과정이 필요하다. 본 연구에서는 수작업을 최소화하기 위해 기존의 고정식 스캔 시스템을 대체할 수 있는 이동식 스캔 시스템을 제안하고자 하며, 기반 기술로 graph-based SLAM을 적용하였다. 테스트 장비는 총 세 개의 2차원 스캐너를 탑재하고 있으며, 중앙의 한 개는 수평으로 설치되어 graph 구축을 통한 이동경로취득에 사용되었고, 좌우 두 개는 수직으로 설치되어 시스템 진행의 연직 방향으로 주변 구조물에 대한 3차원 스캔 정보 취득에 사용되었다. 개발된 graph-based SLAM은 이동경로 상에 누적된 위치오차를 해소하기 위한 loop closure 처리 방법으로 Adaboost 기계학습을 적용하였다. 이는 특히 본 연구에서 사용한 장비와 같이 기계학습을 위한 다수의 feature 정보를 제공할 수 있는 멀티 스캐너 시스템에 적합한 방식이며, 두 실내공간을 대상으로 한 테스트에서 단일 스캐너 대비 false positive rate를 각각 7.9% 및 13.6%까지 줄일 수 있었다. 최종적으로 연구대상지역의 2차원 및 3차원 지도 구축을 통해 개발된 graph-based SLAM의 효용성을 확인하였다.

• 한국정보통신학회논문지
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• 제14권3호
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• pp.707-714
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• 2010

패턴생성기로 LFSR(linear feedback shift register)은 기계 자체에 고유의 선형의존성이 있어 패턴을 생성함에 있어 비트의 위치를 이동시켜 수열을 생성하기 때문에 생성되는 패턴들의 상관관계가 높고 따라서 오류 검출률이 낮아지게 된다. 이런 문제점을 해소하기 위하여 scan chain 사이에 XOR 게이트의 조합으로 구성된 페이지 쉬프터를 장착하여 출력 테스트 패턴의 난수성을 높임으로써 LFSR 고유의 선형의존성을 줄이고 오류 검출률을 높이는 연구가 활발히 진행되어 왔다. 본 논문에서는 PRPG(pseudo random pattern generator)로서 특성 다항식을 원시다항식으로 갖는 LFSR을 사용하여 어떤 임의의 두 채널에서 출력되는 이진 수열의 선형 의존성을 줄이기 위한 방법으로 적절한 탭 수를 유지하며 최소의 위상이동차를 보장하는 페이지 쉬프터를 갖는 LFSR 기반의 PRPG를 구성하는 방법을 제안한다. 제안된 알고리즘에 따라 페이지 쉬프터를 구성하면 기존의 방법보다 페이지 쉬프터를 훨씬 빨리 구성 할 수 있는 장점이 있다.

• 한국IT서비스학회지
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• 제17권3호
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• pp.53-61
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• 2018

In this paper, we propose a car sealing monitoring system combined with ICT Technology. The automobile sealer is an adhesive used to bond inner and outer panels of doors, hoods and trunks of an automobile body. The proposed car sealer monitoring system is a system that can accurately and automatically inspect the condition of the automobile sealer coating process in the general often factory production line where the lighting change is very severe. The sealer inspection module checks the state of the applied sealer using an area scan camera. The vision inspection algorithm is adaptive to various lighting environments to determine whether the sealer is defective or not. The captured images and test results are configured to send the task results to the task manager in real-time as a smartphone app. Vision inspection algorithms in the plant outdoors are very vulnerable to time-varying external light sources and by configuring a monitoring system based on smart mobile equipment, it is possible to perform production monitoring regardless of time and place. The applicability of this method was verified by applying it to an actual automotive sealer application process.

• 비파괴검사학회지
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• 제27권3호
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• pp.246-254
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• 2007

The scanning laser source (SLS) technique is a promising new laser ultrasonic tool for the detection of small surface-breaking defects. The SLS approach is based on monitoring the changes in laser-generated ultrasound as a laser source is scanned over a defect. Changes in amplitude and frequency content are observed for ultrasound generated by the laser over uniform and defective areas. The SLS technique uses a point or a short line-focused high-power laser beam which is swept across the test specimen surface and passes over surface-breaking or subsurface flaws. The ultrasonic signal that arrives at the Rayleigh wave speed is monitored as the SLS is scanned. It is found that the amplitude and frequency of the measured ultrasonic signal have specific variations when the laser source approaches, passes over and moves behind the defect. In this paper, the setup for SLS experiments with full B-scan capability is described and SLS signatures from small surface-breaking and subsurface flaws are discussed using a point or short line focused laser source.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.650-655
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• 1993

Carbon/epoxy composite(CFRP) coupons previously damaged by low velocity impact were tested under static tensile loading and microscope progress of damage was characterized by ultrasonic C-scan, Scanning Acoustic Microscopy (SAM) and Acoustic Emission(AE) techniques which were based on the application of elastic waves. The degress of impact damage has been correlated with the AE activity during monotonic or loading/unloading tensile testing as well as the result of ultrasonic test. The coupons were subjected to impact velocities ranged from 0.71 to 2.17 m/sec, which introduced the amount of damage rated as 0%, 10%, 30%, and 50% with reference to the total absorbed energy at fracture. Special attention was paid to determine optimal AE parameters to characterize the microscopic fracture process and to predict the residual strength of composite laminates. AE RMS voltage during the early stage of tensile loading was found an effective parameter to quantify the degree of impact damage. It was also found that the Felicity ratio is closely related to the stacking sequence and the residual strength of the CFRP laminates.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권4호
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• pp.402-409
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• 2013

An innovative application of voltage-contrast (VC) inspection allowed inline detection of NMOS leakage in dense SRAM cells is presented. Cell sizes of SRAM are continual to do the shrinkage with bit density promotion as semiconductor technology advanced, but the resulting challenges include not only development of smaller-scale devices, but also intra-devices isolation. The NMOS leakage caused by the underneath n+/P-well shorted to the adjacent PMOS/N-well was inspected by the proposed electron-beam (e-beam) scan in which VC images were compared during the in-line process step of post contact tungsten (W) CMP (Chemical Mechanical Planarization) instead of end-of-line electrical test, which has a long response time. A series of experiments based on the mechanism for improving the intra-well isolation was performed and verified by the inline VC inspection. An optimal process-integration condition involved to the tradeoff between the implant dosage and photo CD was carried out.

• 한국레이저가공학회지
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• 제18권3호
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• pp.1-5
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• 2015

A 3D printer based on laser powder deposition (LPD), also known as DED (direct energy deposition), has been developed for fabricating metal parts. The printer uses a ytterbium fiber laser (1070nm, 1kW) and is equipped with an Ar purge chamber, a three-dimensional translation stage and a powder feeding system composed of a powder chamber and delivery nozzles. To demonstrate the performance of the printer, a tapered cylinder of 320mm in height has been fabricated successfully using Ti-6Al-4V powders. The process parameters including the laser output power, the scan speed, and the powder feeding rate have been optimized. A 3D printed test specimen shows mechanical properties (yield strength, ultimate tensile strength, and elongation) exceeding the criteria to employed in a variety of Ti alloy applications.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.30-38
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• 2018

Electronic control units (ECUs) are currently popular, and have evolved further towards the high-end application of autonomous vehicles in the automotive industry. Such digital technologies have also become widespread, in agriculture and construction equipment. Likewise, transmission control of high-speed tracked vehicles is based on the transmission control unit (TCU), performing complex gear change control functions, and diagnostic algorithms (a TCU's self-diagnostic and reporting capability of malfunction data through CAN communication). Since all functions of TCU are implemented by embedded-software, it is hardly possible to analyze specifications by reverse engineering. In this paper a real-time transmission simulator adaptable to TCU is presented, for analysis of diagnosis algorithm and standards. Signal simulation circuits are deliberately designed considering electrical characteristics of TCU inputs and various analysis tools, such as analog input auto scan function, and global output enable switch, are implemented in software. Test results from hardware-in-the-loop simulator verify tolerance time for each error, as well as cause of fault, error reset conditions.