• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.1939-1951
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• 1994

This study introduces a new tool breakage detecting technology comprised of an unsupervised neural network combined with adaptive time series autoregressive(AR) model where parameters are estimated recursively at each sampling instant using a parameter adaptation algorithm based on an RLS(Recursive Least Square). Experiment indicates that AR parameters are good features for tool breakage, therefore it can be detected by tracking the evolution of the AR parameters during milling process. an ART 2(Adaptive Resonance Theory 2) neural network is used for clustering of tool states using these parameters and the network is capable of self organizing without supervised learning. This system operates successfully under the wide range of cutting conditions without a priori knowledge of the process, with fast monitoring time.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.269-280
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• 2011

Mobile Augmented Reality (mobile AR), as one of the most prospective mobile applications, intends to provide richer experiences by annotating tags or virtual objects over the scene observed through camera embedded in a handheld device like smartphone or pad. In this paper, we analyzed the current status of the art of mobile AR and proposed a novel Points of Interest (POIs) data model based on ontology to provide context-aware information retrievals on lots of POIs data. Proposed ontology was expanded from the standard POIs data model of W3C POIs Working Group and established using OWL (Web Ontology Language) and Protege. We also proposed a context-aware mobile AR platform which can resolve three distinguished issues in current platforms : interoperability problem of POI tags, POIs data retrieval issue, and context-aware service issue.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.89-94
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• 1995

A16061, SB41 and SM45C was used for developing tool wear monitoring system in face milling. First of all, Neural networks of which input are 8 $_{th}$ order AR morel parameters, frequency band energies, cutting conditions was used to monitor tool wear for each material. Finally, A unified neural network, which has tensile strengths of each material as an additional input, was constructed to consider the effect three materials on the features of tool wear. It was verified that tensile strength is the one of properties of workpiece materials.s.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.6
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• pp.221-226
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• 2006

The current flowing though a power line is measured by a current transformer (CT). Since a CT is a kind of transformer, saturation of magnetic flux in the core may occur when a large primary current flows. This saturation makes the secondary current of a CT distorted and causes problems in the protection point of view. Because of the current distortion, a protection relay cannot collect the correct information showing how the primary power system changed. Consequently, the current distortion may cause the mal-operation or operation time delay of protective relay. In this paper, an algorithm based on AR model and LSQ is proposed to compensate the saturated CT secondary currents. Various test results indicate that the proposed algorithm can accurately compensate a severely distorted secondary current and is not affected by remanence.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.77-78
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• 1992

In this study, the PSD and coherence spectra of electroencephalogram are estimated us ins multichannel AR model. This enables us to perform the topographic mapping of EEG by interpolation.

• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.223-230
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• 1987

In this paper the harmonic degrees between $\alpha$ wave and $\beta$ wave in visual evoked potential are analyzed by the bicoherence. The bicoherence analysis is based on an AR model which provides significantly better resolution than that of Fourier transform. The analysis results of visual evoked pope ntial are compared with the analysis results of background EEC. From the comparison results it is found that the harmonic degree of visual evoked potential is less than she harmonic degree of background EEG and the $\beta$ wave of visual evoke potential unlike the background EEC contains the non harmonic property of a wave more than the harmonic properity

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1015-1018
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• 2017

본 논문에서는 바람의 방향제어가 어려운 기존 Unity windzone의 한계를 극복하는 spot windzone을 구현하고, 이를 cloth 모델과의 상호작용에 적용한 windcloth 시뮬레이터를 제시한다. 제안 spot windzone은 Unity windzone의 고정된 방향과 범위 문제점을 해결하기 위해 boxcast를 도입하여 방향과 영향권에 있는 cloth만을 감지하여 해당 Cloth에게만 외부 힘을 작동하도록 구현하였다. Spot windzone은 Vuforia를 이용하여, 목표이미지(Target Image)와 연결함으로써, 바람에 의한 cloth 움직임을 보다 직관적인 AR 기반 상호작용 방법으로 확인할 수 있도록 하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.440-440
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• 2010

$SF_6$ 기체 및 Ar/$SF_6$ 혼합 기체 방전은 실제 반도체 및 디스플레이 공정에서 널리 쓰이고 있지만, 측정상의 어려움으로 인하여 정량적인 데이터 및 기본 연구가 부족한 실정이다. 본 연구는 유도 결합 Ar/$SF_6$ 혼합 기체 플라즈마에서 다양한 압력과 혼합 가스 비율에 따른 전자 에너지 분포 측정을 통한 플라즈마 변수 연구에 관한 내용이다. 낮은 가스 압력에서 $SF_6$ 기체의 혼합 비율이 증가함에 따라서 상대적으로 적은 전자 밀도 감소와 전자 온도의 증가가 보였다. 하지만, 높은 가스 압력에서 $SF_6$ 기체의 혼합 비율이 증가함에 따라 상당한 전자 밀도 감소와 급격한 전자 온도 증가 (~ 9 eV)가 관찰되었다. 이러한 전자 온도와 전자 밀도의 극적인 변화는 $SF_6$ 기체 증가에 의한 전자-중성종 충돌과 음이온 생성으로 인한 것으로 여겨지며, 유체 모델 및 전자 가열 모드를 고려하여 해석하였다.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.185-193
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• 1997

This paper presents the on-line monitoring of the surface roughness in a face milling operation. The cut- ting force was used to monitor the surface roughness, since the insert run-outs not only deteriorate surface roughness but also change cutting force. AR model and band energy method were taken to extract the fea- tures from the cutting force. The features extracted from AR modelling are more accurate about the moni- toring than those from band energy method, whereas, the computing speed of the former is slow. An artifi- cal neural network discriminated the level of the surface roughness by using the features extracted via signal processing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.507-515
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• 2014

Benign prostatic hyperplasia (BPH), which is commonly found in aging men, is characterized by hyperplasia of prostatic stromal and epithelial cells beginning in the periurethral zone of the prostate. The prevalence of BPH increases in an age-dependent manner. Here, we investigated the protective effects of unripe Rubus occidentalis extracts (UROE) on BPH development using a prostate cancer cell line and testosterone-induced BPH rat model. Experiments using an established hormone-dependent prostate cancer cell line (LNCaP) showed that UROE treatment significantly decreased expression of androgen-related genes, including androgen receptor (AR), prostate specific antigen (PSA), and 5-alpha reductase 2, but not 5-alpha reductase 1, which was also observed in flutamide-treated cells. Further, AR and PSA gene expression was reduced by UROE treatment under androgen-stimulated conditions using dihydrotestosterone (DHT). BPH animals displayed elevated prostate weights. However, UROE as well as finasteride treatment significantly reduced prostate weights and DHT levels compared to testosterone-induced BPH animals. Histopathological analysis also showed that UROE treatment suppressed testosterone-induced prostatic hyperplasia. Taken together, the results suggest that UROE may effectively inhibit the development of BPH and thus may be a useful agent in BPH treatment.