• Composites Research
• /
• 제17권1호
• /
• pp.1-9
• /
• 2004

본 연구에서는 타격음을 이용한 비파괴 검사법을 제안하였다. 제안된 방법(tapping sound analysis)은 건강한 구조물과 손상된 구조물의 타격음의 차이를 분석하여 구조물의 손상 유무를 판단하는 방법이다. 타격음의 직접적인 비교는 비효율적이므로 타격음으로부터 특성을 추출하기 위해 wavelet packet transform에 기반한 특성추출법을 제안하였다. 또한 추출된 특성 자료를 바탕으로 손상의 유무를 판단하는 지표로서 특성 지수를 정의하였다. 제안된 방법의 타당성을 밝히기 위해 실험적인 검증을 수행하였다. 복합재료를 이용하여 건강한 구조물과 손상된 구조물을 제작하고 타격음을 측정하였다. 제안된 손상 판단 기법을 이용한 결과로부터 특성 지수에 의한 손상 판단의 타당성을 밝혔다.

• 한국측량학회:학술대회논문집
• /
• 한국측량학회 2006년도 춘계학술발표회 논문집
• /
• pp.469-473
• /
• 2006

In general, a classification process between ground data and non-ground data, which include building objects, is required prior to producing a DEM for a certain surface reconstruction from LiDAR data in which the DEM can be produced from the ground data, and certain objects like buildings can be reconstructed using non-ground data. Thus, an exact classification between ground and non-ground data from LiDAR data is the most important factor in the ground reconstruction process using LiDAR data. In particular, building objects can be largely used as digital maps, orthophotos, and urban planning regarding the object in the ground and become an essential to providing three dimensional information for certain urban areas. In this study, an entropy theory, which has been used as a standard of disorder or uncertainty for data used in the information theory, is used to apply a more objective and generalized method in the recognition and segmentation of buildings from raw LiDAR data. In particular, a method that directly uses the raw LiDAR data, which is a type of point shape vector data, without any changes, to a type of normal lattices was proposed, and the existing algorithm that segments LiDAR data into ground and non-ground data as a binarization manner was improved. In addition, this study proposes a generalized building extraction method that excludes precedent information for buildings and topographies and subsidiary materials, which have different data sources.

• ETRI Journal
• /
• 제42권5호
• /
• pp.761-772
• /
• 2020

This paper presents an automatic proficiency assessment method for a non-native Korean read utterance using bidirectional long short-term memory (BLSTM)-based acoustic models (AMs) and speech data augmentation techniques. Specifically, the proposed method considers two scenarios, with and without prompted text. The proposed method with the prompted text performs (a) a speech feature extraction step, (b) a forced-alignment step using a native AM and non-native AM, and (c) a linear regression-based proficiency scoring step for the five proficiency scores. Meanwhile, the proposed method without the prompted text additionally performs Korean speech recognition and a subword un-segmentation for the missing text. The experimental results indicate that the proposed method with prompted text improves the performance for all scores when compared to a method employing conventional AMs. In addition, the proposed method without the prompted text has a fluency score performance comparable to that of the method with prompted text.

• 대한원격탐사학회지
• /
• 제9권2호
• /
• pp.7-19
• /
• 1993

In stereo vision, when we use two parallel axis images, small portion of object is contained and B/H(Base-line to Height) ratio is limited due to the size of object and depth information is inaccurate. To overcome these difficulities we take a non-parallel axis image which is rotated $\theta$ about y-axis and match other parallel-axis image. Epipolar lines of non-parallel axis image are not same as those of parallel-axis image and we can't match these two images directly. In this paper, we transform the non-parallel axis image geometrically with camera parameters, whose epipolar lines are alingned parallel. NCC(Normalized Cross Correlation) is used as match measure, area-based matching technique is used find correspondence and 9$\times$9 window size is used, which is chosen experimentally. Focal length which is necessary to get depth information of given object is calculated with least-squares method by CCD camera characteristics and lenz property. Finally, we select 30 test points from given object whose elevation is varied to 150 mm, calculate heights and know that height RMS error is 7.9 mm.

• 한국측량학회:학술대회논문집
• /
• 한국측량학회 2004년도 춘계학술발표회논문집
• /
• pp.309-312
• /
• 2004

In mountainous area with high relief, topography may cause cast shadows due to the blocking of direct solar radiation. Remote sensing images of these landscapes display reduced values of reflectance for shadowed areas compared to non-shadowed areas with similar surface cover characteristics. A variety of approaches are possible, though a common step in various active approaches is first to delineate the shadows using automated algorithm and digital surface model (or digital elevation model). This articles demonstrates a common confusion caused by cast shadows

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
• /
• pp.725-730
• /
• 1998

Recently we extended the fuzzy model for rule based systems incorporating an importance factor for each rule. The model permits for both unrestricted as well as non-negative importance factors. We use this extended model to design a fuzzy rule based classifier system which uses both the firing strength of the rule and the importance factor to decide the class label. The effectiveness of the scheme is established using several data sets.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제10권2호
• /
• pp.160-164
• /
• 2010

The radio frequency (RF) model of SOI FinFETs with gate length of 40 nm is verified by using a 3-dimensional (3-D) device simulator. This paper shows the equivalent circuit model which can be used in the circuit analysis simulator. The RMS modeling error of Y-parameter was calculated to be only 0.3 %.

• 대한치과교정학회지
• /
• 제52권5호
• /
• pp.383-384
• /
• 2022

• Clinical and Experimental Reproductive Medicine
• /
• 제24권1호
• /
• pp.101-109
• /
• 1997

This study was carried to determine the possibility of finding motile spermatozoa and fertilization, pregnancy rate after testicular sperm extraction(TESE) with ICSI in obstructive and non-obstructive azoospermic patients. In 154 cases(132 patients), obstructive azoospermia was 77 cases and non-obstructive azoospermia was 77 cases. In obstructive azoospermia, patients generally showed normal spermatogenesis and included vas agenesis(n=8), multiple vas obstruction(n=7), epididymal obstruction (n=54). Total of 982 retrieved oocytes were obtained and 84.4% were injected. The fertilization rates with 2 PN and cleavage rate were 72.5% and 62.3%, respectively. 30 pregnancies(38.9%) were achieved and the ongoing pregnancies were 22 cases (28.6%). In non-obstructive azoospermia, patients showed hypospermatogenesis(n=49), maturation arrest(n=4), Sertoli cell only syndrome (n=24). The various stages of spermatogenic cell could be retrieved by TESE and could be reached normal fertilization and embryo development with ICSI. Total of 1072 retrieved oocytes obtained and 80.2% were injected. The fertilization rates with 2 PN and cleavage rate were 52.8% and 68.9%, respectively. 22 pregnancies(30.1%) were achieved and the ongoing pregnancies were 19 cases(26.0%). Conclusively, the combination of TESE with ICSI using testicular spermatozoa can achieve normal fertilization and pregnancy rate and effective method in obstructive and non-obstructive azoospermic patients.

• 식품과학과 산업
• /
• 제55권1호
• /
• pp.58-73
• /
• 2022

최근 저칼로리 식품에 대한 수요로 인해 청량 음료 등 다양한 식품에서 비영양 감미료 사용이 증가하고 있다. 소비자들은 혈당 조절이 가능하고 치아 부식 위험이 적으며 낮은 칼로리를 갖는 대체 감미료를 찾고 있으며, 설탕에 비해 감미도가 높은 비영양 감미료가 식품에 널리 사용되고 있다. 식품에 허용되는 감미료 목록 및 함량 기준은 국가마다 다르며, 규제기관과 식품 산업체 등은 감미료가 사용된 제품을 모니터링하여 전세계 규정을 준수하는지 확인하는 것이 중요하다. 또한, 식품첨가물로서 감미료를 국민들이 얼마나 섭취하며, 이로부터 안전성에는 문제가 없는지에 대한 섭취량 평가를 실시하려면 식품 매트릭스에 따른 정확하고, 재현성 있는 분석법이 수반되어야 한다. 즉, 식품산업의 품질 관리, 시장 감시 및 모니터링 등에 적용되는 다양한 감미료를 동시에 분석하기 위해서는 효율적이고 신속한 분석법의 개발이 필수적이고, 해당하는 매트릭스에 따라 용매 추출, 정제 등 적절한 전처리 단계를 수행하는 것이 중요하다. 본 연구에서는 비영양 감미료를 중심으로 최근 분석 동향을 조사하고, 각 식품 유형에 적합한 추출방법을 선택하는 데에 도움이 되도록 방법 및 결과를 제시하였다. 또한 국내 및 국외 공인시험법을 조사하고, HPLC, LC-MS/MS를 이용한 다성분 동시분석에 대한 기술과 FT-IR 등을 이용한 비파괴 분석 기술까지 종합적으로 정리하였다.