• 대한임베디드공학회논문지
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• 제12권3호
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• pp.177-184
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• 2017

High performance non-volatile memory system can mitigate the gap between main memory and storage. However, no single memory devices fulfill the requirements. Non-volatile Dual In-line Memory Module (NVDIMM) consisted of DRAMs and NAND Flashes has been proposed to achieve the performance and non-volatility simultaneously. When power outage occurs, data in DRAM is backed up into NAND Flash using a small-size external energy storage such as a supercapacitor. Backup and restore operations of NVDIMM do not cooperate with the operating system in the NVDIMM standard, thus there is room to optimize its operation. This paper analysis the operation of NVDIMM and proposes a method to reduce backup and restore time. Particularly, data compression is introduced to reduce the amount of data that to be backed up and restored. The simulation results show that the proposed method reduces up to 72.6% of backup and restore time.

• 한국컴퓨터정보학회논문지
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• 제11권3호
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• pp.67-72
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• 2006

인터넷의 급속한 성장과 인터넷 이용자의 급격한 증가로 인해서 컴퓨터 시스템은 점차 복잡하고 규모가 커지고 있으며, 컴퓨터 시스템에 대한 의존도가 점점 더 높아지고 있으므로 실수 또는 재난으로 인한 데이터 손실 피해는 상상할 수 없을 정도로 크다. 일반적으로 인터넷을 통해 정보를 제공하고자 하면 지속적이며 안정적으로 자료를 갱신하여야 하며, 주기적인 백업을 통해 귀중한 자료가 갑작스런 문제로 인해 삭제되지 않도록 관리하여야 한다. 이를 위해 자료를 안전하게 보호하기 위한 방안이 마련되어야 한다. 본 논문은 이러한 정보 관리 측면에서 환경과 수행방법을 고려하여 효과적인 백업 환경을 만들 수 있는 시스템을 제시한다. 즉, 인터넷을 통해 자료 백업과 복구를 선택적으로 수행할 수 있는 시스템을 구현한다. 시스템의 이점으로는 인터넷을 통해 접속 가능하므로 서버에 직접 연결되지 않더라도 브라우저를 통해 저장되어있는 자료를 백업과 복구할 수 있다. 또한 백업과 복구 모두 두 가지 방식을 선택적으로 수행함으로써 보다 효율적으로 서버에 저장된 데이터를 관리할 수 있다.

• 한국정보처리학회논문지
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• 제6권3호
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• pp.722-728
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• 1999

When one link failure happens in BSHR/2 networks, it is possible to restore all traffics by following the ITU-T G.841 rules. However, when a node that is currently executing a ring switch receives a long-path ring bridge request for an higher priority, it shall drop its bridge and switch immediately, then enter full pass-through. Even through link connection between two nodes exists, it is impossible to restore the service. In this paper, when multi-link failures happen, the services through connected link can be restored by exchanging messages through DCC(Data Communication Channel). Partially reconstructing the ring map that is unable to restore services because of multi-link failures made it possible to restore these kinds of traffic pattenrs. This paper shows that the services through connected link can be restored by using proposed method.

• Imaging Science in Dentistry
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• 제50권4호
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• pp.331-337
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• 2020

Purpose: As cone-beam computed tomography (CBCT) has become the most widely used 3-dimensional (3D) imaging modality in the dental field, storage space and costs for large-capacity data have become an important issue. Therefore, if 3D data can be stored at a clinically acceptable compression rate, the burden in terms of storage space and cost can be reduced and data can be managed more efficiently. In this study, a deep learning network for super-resolution was tested to restore compressed virtual CBCT images. Materials and Methods: Virtual CBCT image data were created with a publicly available online dataset (CQ500) of multidetector computed tomography images using CBCT reconstruction software (TIGRE). A very deep super-resolution (VDSR) network was trained to restore high-resolution virtual CBCT images from the low-resolution virtual CBCT images. Results: The images reconstructed by VDSR showed better image quality than bicubic interpolation in restored images at various scale ratios. The highest scale ratio with clinically acceptable reconstruction accuracy using VDSR was 2.1. Conclusion: VDSR showed promising restoration accuracy in this study. In the future, it will be necessary to experiment with new deep learning algorithms and large-scale data for clinical application of this technology.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.367-372
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• 2001

Feature restoration is that restore feature to 3D solid model using the feature information in STEP AP224. Feature is very important in CAPP, but feature information is defined very complicated in STEP AP224. This paper recommends the algorithm of extraction the feature information in physical STEP AP224file. This program import STEP AP224 file, parse the geometric and topological information, the tolerance data, and feature information line-by-line. After importation and parsing, store data into database. Feature restoration module analyze database including feature information, extract feature information, e.g. feature type, feature's parameter, etc., analyze the relationship and then restore feature to 3D solid model.

• 대한원격탐사학회지
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• 제28권6호
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• pp.661-670
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• 2012

Urban forests provide great ecosystem services to population in metropolitan areas even though they occupy little green space in a huge gray landscape. Unfortunately, urbanization inherently results in threatening the green infrastructure, and the recent urbanization trends drew great attention of scientists and policy makers on how to preserve or restore green infrastructure in metropolitan area. For this reason, mapping the spatial distribution of the green infrastructure is important in urban environments since the resulting map helps us identify hot green spots and set up long term plan on how to preserve or restore green infrastructure in urban environments. As a preliminary step for mapping green infrastructure utilizing multi-source remote sensing data in urban environments, the objective of this study is to map vegetation volume by fusing LiDAR and multispectral data in urban environments. Multispectral imageries are used to identify the two dimensional distribution of green infrastructure, while LiDAR data are utilized to characterize the vertical structure of the identified green structure. Vegetation volume was calculated over the metropolitan Chicago city area, and the vegetation volume was summarized over 16 NLCD classes. The experimental results indicated that vegetation volume varies greatly even in the same land cover class, and traditional land cover map based above ground biomass estimation approach may introduce bias in the estimation results.

• 한국측량학회지
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• 제27권2호
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• pp.273-279
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• 2009

문화재를 잘 보존하고 전승하는 것은 후손들의 몫이다. 현재 목조건물 형태의 문화재는 환경적 요인에 의하여 여러 번의 중수와 재건을 한 경우 대부분이다. 본 연구에 활용한 문화재는 11번의 중수와 재건을 한 것으로 초기의 모습이 많이 훼손되었다. 따라서 문화재청에서는 원형으로 복원을 하고자하였다. 그러나 원형 복원을 위한 자료로는 사진해석을 위한 자료가 없는 단 한 장의 사진만 존재한다. 본 연구에서는 자료부족으로 사진측량학적 해석을 하기 어려운 보물 제322호 관덕정의 1900년 이전 사진을 소실점을 이용한 기하학적 해석을 통하여 복원에 필요한 자료를 획득할 수 있었다. 또한 연구 결과로 획득한 자료는 실제 복원을 위한 기초 자료로 제공하였다.

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 동계학술발표회 논문집
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• pp.335-336
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• 2006

We propose a method of encryption and decryption of binary data using 2-step phase-shifting digital interferometry. This technique reduces the number of interferograms in the phase-shifting interferometry. The binary data has been expressed with random code and random phase. We remove the dc-term of the phase-shifting digital interferogram to restore the original binary data. Simulation results shows that the proposed technique can be used for binary data encryption and decryption.

• Journal of Periodontal and Implant Science
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• 제53권6호
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• pp.444-452
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• 2023

Purpose: The aim of this study was to retrospectively evaluate the survival and failure rates of RESTORE^® implants over a follow-up period of 10-15 years at a university dental hospital and to investigate the factors affecting the survival rate of these dental implants. Methods: A total of 247 RESTORE^® dental implants with a resorbable blast media (RBM) surface inserted in 86 patients between March 2006 and April 2011 at the Department of Periodontology of Seoul National University Dental Hospital were included. Patients with follow-up periods of less than 10 years were excluded, and data analysis was conducted based on dental records and radiographs. Results: Over a 10- to 15-year period, the cumulative survival rate of the implants was 92.5%. Seventeen implants (6.88%) were explanted due to implant fracture (n=10, 4.05%), peri-implantitis (n=6, 2.43%), and screw fracture (n=1, 0.4%). The results of univariate regression analysis using a Cox proportional hazards model demonstrated that implants placed in male patients (hazard ratio [HR], 4.542; 95% confidence interval [CI], 1.305-15.807; P=0.017) and implants that supported removable prostheses (HR, 15.498; 95% CI, 3.105-77.357; P=0.001) showed statistically significant associations with implant failure. Conclusions: Within the limitations of this retrospective study, the RESTORE^® dental implant with an RBM surface has a favorable survival rate with stable clinical outcomes.

• Journal of International Society for Simulation Surgery
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• 제1권1호
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• pp.16-18
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• 2014

The orbit has a very special anatomical structure. The complex anatomical structure should be restored when we encounter the patient with orbital wall fracture. Unless these specific anatomy were reconstructed well, the patient should suffer from various complications such enophthalmos, diplopia or orbital deformity. In addition, because the patient has a his own specific orbital shape, individualized approach will be necessary. The aim of this trial is to try to restore the original orbit anatomy as possible based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. In order to restore the missing skipped images between the cuts of CT data because of the thinness of the orbital walls, we manipulated the DICOM data for imaging the original orbital contour using the preoperatively manufactured mirror-image of the RP model. And we fabricated Titanium-Medpor to reconstruct three-dimensional orbital structure intraoperatively. This prefabricated Titanium-Medpor was then inserted onto the defected orbital wall and fixed. Three dimensional approach based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.