• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2001년도 추계학술대회
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• pp.44-55
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• 2001

In the Taguchi parameter design, the product-array approach using orthogonal arrays is mainly used. However, it often requires an excessive number of experiments. An alternative approach, which is called the combined-array approach, was suggested by Welch et. al. (1990) and studied by others. In these studies, only single response variable was considered. We propose how to simultaneously optimize multiple responses when there are correlations among responses, and when we use the combined-array approach to assign control and noise factors.

• Communications for Statistical Applications and Methods
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• 제3권2호
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• pp.103-117
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• 1996

In the Taguchi Parameter design, the product-array approach using orthogonal arrays is mainly used. However, it often requires an excessive number of experiments. An alternative approach, which is called the combined- array approach, was suggested by welch et. al. (1990) and studied by Vining and Myers(1990), Box and Jones (1992) and others. In these studies, only single response variable was considered. We propose how to simultaneously optimize multiple responses when there are correlations among responses, and when we use the combined-array approach to assign control and noise factors.

• Journal of Korean Neurosurgical Society
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• 제60권2호
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• pp.250-256
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• 2017

Objective : Cases of a ruptured pericallosal artery aneurysm with a high risk of intraoperative premature rupture and technical difficulties for proximal vascular control require a technique for the early and safe establishment of proximal vascular control. Methods : A combined pterional or subfrontal approach exposes the bilateral A1 segments or the origin of the ipsilateral A2 segment of the anterior cerebral artery (ACA) for proximal vascular control. Proximal control far from the ruptured aneurysm facilitates tentative clipping of the rupture point of the aneurysm without a catastrophic premature rupture. The proximal control is then switched to the pericallosal artery just proximal to the aneurysm and its intermittent clipping facilitates complete aneurysm dissection and neck clipping. Results : Three such cases are reported : a ruptured pericallosal artery aneurysm with a contained leak of the contrast from the proximal side of the aneurysm, a low-lying ruptured pericallosal artery aneurysm with irregularities on its proximal wall, and a multilobulated ruptured pericallosal artery aneurysm with the parasagittal bridging veins hindering surgical access to the proximal parent artery. In each case, the proposed combined pterional-interhemispheric or subfrontal-interhemispheric approach was successfully performed to establish proximal vascular control far from the ruptured aneurysm and facilitated aneurysm clipping via the interhemispheric approach. Conclusion : When using an anterior interhemispheric approach for a ruptured pericallosal artery aneurysm with a high risk of premature rupture, a pterional or subfrontal approach can be combined to establish early proximal vascular control at the bilateral A1 segments or the origin of the A2 segment.

• Journal of Korean Neurosurgical Society
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• 제39권3호
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• pp.188-191
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• 2006

Objective : The purpose of this study is to evaluate the efficacy and necessity of combined anterior approach [discectomy and fusion] and posterior approach[open-door laminoplasty] in the treatment of cervical spondylotic myelopathy. Methods : The authors reviewed 14 cases in whom combined anterior and posterior approach performed for cervical myelopathy due to simultaneous anterior and posterior pathology such as huge central disc herniation with narrow spinal canal between January 2000 and December 2002. Clinical symptoms were evaluated by Japanese Orthopaedic Association [JOA] score and then the cervical curvature, change of spinal canal to vertebral body[SC/VB] ratio and canal widening were measured and compared to the clinical symptoms. Results : The mean JOA score increased from $10.4{\pm}3.1$ preoperatively to $14.8{\pm}1.2$ at the final follow up with a mean recovery rate 66.4%. In all cases, there were not neurologic deterioration. Mild postoperative complications developed in two cases. One patient had a limitation of range of neck motion and the other one showed kyphotic change. Postoperative radiography showed an improvement of body to canal ratios [average $0.70{\pm}0.08$ before surgery to $1.05{\pm}0.12$ after surgery and mainte nance or recovery of cervical lordosis. Canal widening of antero-posterior diameter and dimension after operation is 6.8mm. $116.61mm^2$. Conclusion : Combined anterior and posterior procedure could be helpful in decompression of the spinal cord and good functional recovery in spondylotic myelopathy patients with combined anterior and posterior pathology such as huge disc herniation accompanying narrow spinal canal.

• Journal of Korean Dental Science
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• 제17권2호
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• pp.92-104
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• 2024

Managing multiple non-carious cervical lesions (NCCLs) with gingival recession and dentin hypersensitivity can be challenging. Herein, we present two cases of successful treatment procedure for multiple NCCLs with gingival recession and dentin hypersensitivity using an envelope coronally advanced flap with CTG and composite resin restoration. Through the combined approach of restorative and periodontal procedure, both patients showed adequate extent of gingival coverage and esthetic outcome based on the Modified Root Coverage Esthetic Score (MRES) at 6 months postoperatively. Also, dentin hypersensitivity was reduced effectively during the follow up period. Although the pocket depth slightly increased in patient 1, possibly due to the amount of restoration located sub-gingivally, pocket depth remained within 3 mm. This suggest that re-establishing the clinical CEJ and performing partial restoration is advantageous for periodontal tissue and is expected to contribute to maintain gingival height in the long term. These case reports emphasize the efficacy of the combined approach for treating multiple NCCLs with gingival recession and dentin hypersensitivity, highlighting the importance of careful restoration planning for optimal clinical and aesthetic outcomes.

• Journal of the Korean Data and Information Science Society
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• 제11권1호
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• pp.65-72
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• 2000

로버스트설계는 품질공학에서 품질특성치의 수행변동(performance variation)을 줄이는데 있다. 다구찌가 제안한 파라미터설계는 아주 많은 장점을 가지고 있으나 몇 가지 단점이 있다. 그 중에서 파라미터설계에 있어서 교차배열은 제어인자와 잡음인자의 모든 교호작용효과를 고려한 실험배치이기 때문에 많은 실험횟수를 필요로 하는 단점이 있다. 그래서 대안방법으로 Welch등(1990)이 제안한 통합배열이 고려된다. 본 논문에서는 로버스트 설계를 위한 다구찌의 파라미터설계(혹은 교차배열방법론)와 통합배열방법론을 시뮬레이션을 통하여 비교 연구하고자 한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.551-556
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• 2004

The theoretical method is developed to investigate the vibration characteristics of the combined cylindrical shells with an annular plate joined to the shell at any arbitrary axial position. The structural rotational coupling between shell and plate is simulated using the rotational artificial spring. For the translational coupling, the continuity conditions for the displacements of shell and plate are used. For the uncoupled annular plate, the transverse motion is considered and the in-plane motions are not. And the additional transverse and in-plane motions of the coupled annular plate by shell deformation are considered in analysis. Theoretical formulations are based on Love's thin shell theory. The frequency equation of the combined shell with an annular plate is derived using the Rayleigh-Ritz approach. The effect of inner-to-outer radius ratio, axial position and thickness of annular plate on vibration characteristics of combined cylindrical shells is studied. To demonstrate the validity of present theoretical method, the finite element analysis is performed.

• 융합신호처리학회논문지
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• 제14권1호
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• pp.13-20
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• 2013

A combined DWT and DCT based watermarking technique of low frequency watermarking with weighted correction is proposed. The DWT has excellent spatial localization, frequency spread and multi-resolution characteristics, which are similar to the theoretical models of the human visual system (HVS). The DCT based watermarking techniques offer compression while DWT based watermarking techniques offer scalability. These desirable properties are used in this combined watermarking technique. In the proposed method watermark bits are embedded in the low frequency band of each DCT block of selected DWT sub-band. The weighted correction is also used to improve the imperceptibility. The extracting procedure reverses the embedding operations without the reference of the original image. Compared with the similar approach by DCT based approach and DWT based approach, the experimental results show that the proposed algorithm apparently preserves superiori mage quality and robustness under various attacks such as JPEG compression, cropping, sharping, contrast adjustments and so on.

• Journal of Positioning, Navigation, and Timing
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• 제3권1호
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• pp.31-36
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• 2014

Precise Point Positioning (PPP) is a stand-alone precise positioning approach. As the quality of satellite orbit and clock products from analysis centers has been improved, PPP can provide more precise positioning accuracy and reliability. A combined use of Global Positioning System (GPS) and Global Orbiting Navigation Satellite System (GLONASS) in PPP is now available. In this paper, we explained about an approach for combined GPS and GLONASS PPP measurement processing, and validated the performance through the comparison with GPS-only PPP results. We also used the measurement obtained from the GRAS reference station for the performance validation. As a result, we found that the combined GPS/GLONASS PPP can yield a more precise positioning than the GPS-only PPP.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1698-1711
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• 2022

A combined safety approach, which uses a best-estimate computer code and adopts conservative assumptions for safety systems availability, is developed and applied to the safety margin evaluation for the Loss of Condenser Vacuum (LOCV) of the 1000 MWe Korean Nuclear Power Plant. The Multi-dimensional Analysis of Reactor Safety-KINS standard (MARS-KS) code is selected as a best-estimate code and the PAPIRUS program is used to obtain different initial operational conditions through random sampling of control variables. During an LOCV event, fuel integrity is not threatened by the increase in Departure from Nuclear Boiling Ratio (DNBR). However, the high pressure in the primary coolant system and the secondary system might affect the system integrity. Thus, the peak pressure becomes a major safety concern. Transient analyses are performed for 124 cases of different initial conditions and the most conservative case, which results in the highest system pressure is selected. It is found the suggested methodology gives similar peak pressures when compared to those predicted from existing methodologies. The proposed approach is expected to minimize the time and efforts required to identify the conservative plant conditions in the existing conservative safety methodologies.