• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권2호
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• pp.149-155
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• 1997

Ridge expansion osteotomy(REO) technique is a simple and more conservation method to widen a narrow alveolar ridge in the maxilla. This method is superior to drilling method in soft and narrow maxillary alveolar ridge and allows the surgeon to widen the ridge in routine office procedure. Therefore, it is the treatment of choice to implant the maxilla with narrow alveolar ridge. This article presents clinical cases and discusses the advantages, rationale and surgical protocol of REO technique.

• 대한의생명과학회지
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• 제13권4호
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• pp.369-374
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• 2007

A fingerprint is an impression of the friction ridges of all or any part of the finger. A friction ridge is a raised portion of the epidermis on the palmar (palm and fingers) or plantar (sole and toes) skin, consisting of one or more connected ridge units of friction ridge skin. There are two fundamental principles underlying the use of fingerprints as a means of identifying individuals - immutability and uniqueness. Friction ridges develop on the fetus in their definitive form before birth. Ridges are persistent throughout life except for permanent scarring. Ridge patterns and the details in small areas of friction ridges are unique and never repeated. Friction ridge patterns vary within limits, which allow for classification. We developed the high temperature-moisturizing method to obtained quality postmortem impressions from decomposing friction ridge skin. This technique is a simple procedure that uses boiling water to recondition the skin. This reconditioning process enhances detail present on the fingers and exposes ridge detail not visible to the naked eye. Therefore, we can recover the quality fingerprints, even from the worst decomposed bodies.

• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.1-10
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• 1999

When the component proportions in mixture experiments are restricted by lower and upper bounds multicollinearity appears all too frequently. The ridge regression can be used to stabilize the coefficient estimates in the fitted model. I propose a graphical method for evaluating the mixture component effects of ridge regression estimator with respect to the prediction variance and the prediction bias.

• Journal of the Korean Data and Information Science Society
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• 제18권1호
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• pp.51-61
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• 2007

Ridge regression (RR), principal component regression (PCR) and partial least squares regression (PLS) are among popular regression methods for collinear data. While RR adds a small quantity called ridge constant to the diagonal of X'X to stabilize the matrix inversion and regression coefficients, PCR and PLS use latent variables derived from original variables to circumvent the collinearity problem. One problem of PCR and PLS is that they are very sensitive to overfitting. A new regression method is presented by combining RR and PCR and PLS, respectively, in a unified manner. It is intended to provide better predictive ability and improved stability for regression models. A real-world data from NIR spectroscopy is used to investigate the performance of the newly developed regression method.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 춘계종합학술대회
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• pp.468-471
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• 2004

본 논문에서는 런길이부호화를 이용하여 지문영상의 융선을 분류하는 방법을 연구하였다. 자동지문인식 시스템에서 단점, 분기점과 같은 특징점을 검출하기 위해 지문영상의 융선을 분류할 필요가있다. 본 논문에서는 분할된 지문영상을 런길이 부호화를 이용하여 지문융선을 분류하는 방법을 제안한다. 또한 융선의 분류와 동시에 각 런의 중심점을 연결하는 지문 세선화과정이 수행되고, 분기점 및 단점이 포함된 특징영역을 동시에 검출할 수 있다. 제안방법의 성능평가를 위해 지문영상을 사용하여 분기점 및 단점을 포함하는 특징영역을 검출하고, 동시에 지문융선을 분류할 수 있음을 보였다.

• Bulletin of the Korean Chemical Society
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• 제22권1호
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• pp.37-42
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• 2001

Ridge regression is compared with multiple linear regression (MLR) for determination of Research Octane Number (RON) when the baseline and signal-to-noise ratio are varied. MLR analysis of near-infrared (NIR) spectroscopic data usually encounters a collinearity problem, which adversely affects long-term prediction performance. The collinearity problem can be eliminated or greatly improved by using ridge regression, which is a biased estimation method. To evaluate the robustness of each calibration, the calibration models developed by both calibration methods were used to predict RONs of gasoline spectra in which the baseline and signal-to-noise ratio were varied. The prediction results of a ridge calibration model showed more stable prediction performance as compared to that of MLR, especially when the spectral baselines were varied. . In conclusion, ridge regression is shown to be a viable method for calibration of RON with the NIR data when only a few wavelengths are available such as hand-carry device using a few diodes.

• Journal of Communications and Networks
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• 제17권5호
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• pp.491-498
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• 2015

Recognition of radar emitter signals is one of core elements in radar reconnaissance systems. A novel method based on singular value decomposition (SVD) and the main ridge slice of ambiguity function (AF) is presented for attaining a higher correct recognition rate of radar emitter signals in case of low signal-to-noise ratio. This method calculates the AF of the sorted signal and ascertains the main ridge slice envelope. To improve the recognition performance, SVD is employed to eliminate the influence of noise on the main ridge slice envelope. The rotation angle and symmetric Holder coefficients of the main ridge slice envelope are extracted as the elements of the feature vector. And kernel fuzzy c-means clustering is adopted to analyze the feature vector and classify different types of radar signals. Simulation results indicate that the feature vector extracted by the proposed method has satisfactory aggregation within class, separability between classes, and stability. Compared to existing methods, the proposed feature recognition method can achieve a higher correct recognition rate.

• 한국콘텐츠학회논문지
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• 제16권3호
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• pp.328-334
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• 2016

본 연구는 보철치료의 최종 목적인 결손치아 및 그 주위 조직의 정상적 기능의 회복과 유지를 위한 전치부 교의치의 반 자정(ridge lap)형 가공치의 체계적인 제작 방법을 연구하였다. 가공치가 갖추어야 할 설계 기준를 제도화 하였고, 치과의사의 소견으로 염증, 치주질환, 음식물 잔류 및 자정작용의 효과가 기존의 제작 방법보다 더 우수한 결과를 얻었다. 본 논문에서 제시하는 가공치 제작방법은 임상에 적용해도 무방하다고 판단된다.

• 대한치과의사협회지
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• 제53권8호
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• pp.545-557
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• 2015

The modified ridge splitting/expansion technique combined with guided bone regeneration (GBR) for implant surgery is used to expand the narrow and atrophied edentulous alveolar ridge. Also, the simultaneous implant placement after ridge splitting/expansion technique can reduce the treatment and healing time. This case report includes three patients with a narrow edentulous alveolar ridge of the 2 to 4mm. All three patients underwent a fracture of thin buccal cortical bone plate, and these defects were corrected by the use of the guided bone regeneration (GBR). After 7 to 18 months, all surgical area was stable, and all implant showed a good healing state on the clinical and radiographic examination. In conclusion, though this surgical method is technique sensitive, the modified ridge splitting/expansion technique combined with GBR for implant surgery is recommended for a horizontal augmentation in the narrow edentulous alveolar ridge.

• Advances in nano research
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• 제4권3호
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• pp.157-165
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• 2016

The photocatalytic (PC) activity of anatase titania nanoparticles can be improved through codoping with transition metals and nitrogen. In addition, the PC activity can also be improved by creating monodisperse, mesoporous nanoparticles of titania. The question naturally arose as to whether combining these two characteristics would result in further improvement in the PC activity or not. Herein, we describe the synthesis and photocatalytic characteristics of codoped, monodisperse anatase titania. The transition metals tested in the polydisperse and the monodisperse forms were Mn, Co, Ni, and Cu. In each case, it was found that the monodisperse version had a higher PC activity compared to the corresponding polydisperse version.