• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.180-194
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• 2021

For small image registration, feature-based approaches are likely to fail as feature detectors cannot detect enough feature points from low-resolution images. The classic FFT approach's prediction accuracy is high, but the registration time can be relatively long, about several seconds to register one image pair. To achieve real-time and high-precision rigid registration for small images, we apply deep neural networks for supervised rigid transformation prediction, which directly predicts the transformation parameters. We train deep registration models with rigidly transformed CIFAR-10 images and STL-10 images, and evaluate the generalization ability of deep registration models with transformed CIFAR-10 images, STL-10 images, and randomly generated images. Experimental results show that the deep registration models we propose can achieve comparable accuracy to the classic FFT approach for small CIFAR-10 images (32×32) and our LSTM registration model takes less than 1ms to register one pair of images. For moderate size STL-10 images (96×96), FFT significantly outperforms deep registration models in terms of accuracy but is also considerably slower. Our results suggest that deep registration models have competitive advantages over conventional approaches, at least for small images.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.594-597
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• 2006

Image co-registration is the process of overlaying two images of the same scene. One of which is a reference image, while the other (sensed image) is geometrically transformed to the one. Numerous methods were developed for the automated image co-registration and it is known as a time-consuming and/or computation-intensive procedure. In order to improve efficiency and effectiveness of the co-registration of satellite imagery, this paper proposes a pre-qualified area matching, which is composed of feature extraction with Laplacian filter and area matching algorithm using correlation coefficient. Moreover, to improve the accuracy of co-registration, the outliers in the initial matching point should be removed. For this, two outlier detection techniques of studentized residual and modified RANSAC algorithm are used in this study. Three pairs of Landsat images were used for performance test, and the results were compared and evaluated in terms of robustness and efficiency.

• 한국정보통신학회논문지
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• 제25권6호
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• pp.799-806
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• 2021

정합은 고유 좌표를 가지고 있는 점군을 전역 좌표로 변환하는 과정이다. 지역 정합은 계산 시간이 오래 걸리고 대략적인 위치를 맞춘 후 정밀 정합을 수행하고, 전역 정합은 정합에 이용할 대응점을 계산하고 한 번에 정합하기 때문에 일반적으로 지역 정합법에 비해 속도가 빠르고, 초기 위치에도 상관이 없다. 전역 정합 방법 중 고속 전역 정합법은 성능이 우수하여 많이 사용하는 방법 중 하나이다. 하지만 정합 정밀도와 속도를 높이기 위해서는 많은 매개변수가 필요하다. 본 논문에서는 이와 같은 매개변수들을 분석하고 실험하여 실제 정합 시 유효하게 작용하는 매개변수를 제안한다. 제안한 결과는 고속 전역 정합법을 활용해야 하는 경우 방향 설정에 도움이 될 것이다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.181-185
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• 2006

Image co-registration is the process of overlaying two images of the same scene, one of which represents a reference image, while the other is geometrically transformed to the one. In order to improve efficiency and effectiveness of the co-registration approach, the author proposed a pre-qualified area matching algorithm which is composed of feature extraction with canny operator and area matching algorithm with cross correlation coefficient. For refining matching points, outlier detection using studentized residual was used and iteratively removes outliers at the level of three standard deviation. Throughout the pre-qualification and the refining processes, the computation time was significantly improved and the registration accuracy is enhanced. A prototype of the proposed algorithm was implemented and the performance test of 3 Landsat images of Korea showed: (1) average RMSE error of the approach was 0.436 Pixel (2) the average number of matching points was over 38,475 (3) the average processing time was 489 seconds per image with a regular workstation equipped with a 3 GHz Intel Pentium 4 CPU and 1 Gbytes Ram. The proposed approach achieved robustness, full automation, and time efficiency.

• 한국멀티미디어학회논문지
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• 제7권12호
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• pp.1708-1718
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• 2004

In this paper, we are concerned with a digital fingerprinting scheme for multi-purchase where a buyer wants to buy more than a digital content. If we apply previous schemes to multi-purchase protocol, the number of execution of registration step and decryption key should be increased in proportion to that of digital contents to be purchased in order to keep unlinkability. More worse, most of fingerprinting schemes in the literature are based on either secure multi-party computation or general zero-knowledge proofs with very high computational complexity. These high complexities complicate materialization of fingerprinting protocol more and more. In this paper, we propose a multi-purchase fingerprinting scheme with lower computational complexity. In the proposed scheme, a buyer executes just one-time registration step regardless of the number of contents to be purchased. The number of decryption key is constant and independent of the number of contents to be purchased. We can also reduce the computational costs of buyers by introducing a concept of proxy-based fingerprinting protocol.

• 정보보호학회논문지
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• 제27권6호
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• pp.1251-1259
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• 2017

고정된 패스워드 그리고 패스워드의 사전공유라는 단순 패스워드가 지니는 문제점을 해결하기 위해 해시체인 기반의 일회용 패스워드가 제안되었다. 루트 해시값을 사전에 등록시킨 후에 사용하기 때문에 고정된 패스워드의 문제점을 해결하였으나, 해시체인을 구성하는 해시값들이 소진된 이후에는 새로운 해시체인의 루트 값을 재등록 하는 단점을 가지고 있다. 재등록을 필요로 하지 않는 여러 유형의 해시체인 기반의 일회용 패스워드 기법들이 제안되었으나, 제약조건 및 효율성 측면에서 문제점들을 내포하고 있다. 본 논문에서는 재등록이 요구되지 않으면서 기존 제약조건을 만족하면서도 매 인증 시 각 2회의 암호해시함수만으로 일회용 패스워드를 생성하고 이를 검증하는 해시체인 기반의 일회용 패스워드 기법을 새로이 제안하고 기존 기법들과 보안요구사항 및 효율성 측면에서 비교 분석한다.

• 한국정보통신학회논문지
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• 제25권5호
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• pp.652-658
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• 2021

3D 스캐너를 이용하여 점군을 획득 시 각각의 고유한 좌표를 기준으로 취득한 데이터를 통일된 좌표체계를 가진 하나의 데이터로 만드는 과정이 필요하고 이 과정을 정합이라고 한다. 정합 과정은 한 번의 수행으로 만족할만한 결과를 얻기 힘들며 여러 차례 반복하여 정합 정밀도를 높인다. 정합의 정밀도를 판단하는 기준은 중요한 요소이다. 기존에 정합의 정밀도를 파악하는 방법은 경우에 따라 판단 기준이 모호할 수 있으며, 점군 데이터의 특성에 따라 매번 다른 결과가 나올 수 있는 한계점을 가지고 있다. 이에 본 연구에서는 정합의 정밀도는 좀 더 정확하게 계산하기 위하여 정합에서 사용하는 대응점이 아닌 전체 점군에 대해서 점군의 평균 거리 값을 이용한 방법을 제안한다. 이 방법을 사용할 경우 기존의 방법에 비하여 좀 더 확실하게 정합의 정밀도를 파악할 수 있다.

• 한국인구학
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• 제11권1호
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• pp.58-75
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• 1988

1.Objectives of the Study It is a well known fact that a prompt and reliable data on demographic information is essential in a proper planning and evaluation of any program of national or community level. Especially vital statistics are an important demographic component among demographic information. Realizing the importance of vital statistics, the government has made some efforts for years to improve the vital registration system which has a close relationship with the production of vital statistics. However, it is still observed that there are some limitations in utilizing vital registration data due to considerable amount of vital events which are never registered and registered but not in time or inaccurately, even though vital registration system in Korea has sound legal basis. In this connection, the objectives of the study is as follows :(1) To examine some problems of the vital registration system in various aspects, (2) To make improvement programme of continuous Demographic Survey as a supplementary source of vital statistics, and (3) To find out some alternatives for making it possible to produce and utilize the reliable vital statistics by developing analytical methodologies on that. 2. Current Situation of Vital Registration System All the vital events, i.e. births, deaths, marriages and divorces, are to be registered in time under the Civil Registration Law, Statistics Law and Regulation on Vital Statstics as a duty of people. Some recent tendencies in each of recent registration are summarized as below: (1) The completeness of vital registration .Out of all births which are occurred during a year, around 75% of those compared to the estimates are registered in the year of occurrence. .In case of death registration, the percentage of registration in the year of occurrene has been gradually increased from 86.2% in the year of 1980, but it is still below the level of 90% compared to the estimates. .The percentage of registration for marriages and divorces in the year of occurrence out of total registered numbers was revealed to be 69% and 73% respectively in 1985. (2) Continuous Demographic Survey .It is a kind of sample survey for the purpose of producing reliable vital statistics which could not be provided by the vital registration. .It covers about 17, 000 sample households at national level and important information for vital events are collected in every month by 323 expertized enumerators who are regular staff of the government. .Although the result of the survey seems to be more reliable than of vital registration, the reliability of the data is still bellow the acceptable level if compared with relevant information from other sources such as population census or special surveys. 3. Problems of Vital Registration System There are four major obstacles in improving vital registration system in Korea; (1) In general, policy priority is not given on any programme of improving vital registration system. It is, therefore, very difficult to formulate comprehensive programme through having cooperation from related authorities and sufficient financial assistance. (2) In all the laws related and system itself, there is substantial degree of overlap and irrationality. Registration of each vital event is maintained according to several laws and regulation such as Civil Registration Law, Statistics Law, Resident Registration Law and Regulation on Vital Statistics. However they are mutually overlapped and overall supervision can not be done systematically due to lack of co-operation among the authorities concerned. (3) The administration of vital registration system seems to be working inefficiently, because of most of civil servants who are in charge of vital registration are lacking of conception on vital statistics and also there is a certain extent of regidity in handling the works. Therefore, they are doing their jobs in a passive way. (4) A substantial proportion of vital events occurred is not registered within the legal time limit (i.e. within one month after the occurrence in case of birth and death) or not registered forever. Some of social customs and superstitution seem to be the potential causes especially in case of births and deaths. 4. Recommendations for the Improvement of Vital Statistics (1) Reporting systems such as civil registration, vital statistics and resident registration should be integrated under the single law. Also, administrative supervision, personnel and budget with regard to the registration system should be under the control of a single ministry. (2) It is necessary to simplify the procedures and methods of reporting vital events, i.e., reducing number of sheets of the form, making corrections easily, reducing registration items, etc. (3) Continuous Demographic Survey as a supplementary source of vital registration should be improved and special ad-hoc surveys should be conducted wth regular interval. (4) In-depth analysis should be done using various sources of data on vital statistics. 5. Concluding Remarks From this study, we can notice that temporary campaign and motivation programs are not sufficient to improve the quality of vital statistics. Strong intentions and continuous efforts of the government are needed for the improvement of the vital registration system. Furthermore, most of the data collected through the registration are not properly analyzed and utilized, partly due to the lack of appreciation among high-level governmental officials of the need for vital statistics. It is, therefore, requested that long-term improvement programs of vital statistics be implemented with policy priority and continuous efforts be given to this purpose as a long-term goal of development in Korea.

• 한국콘텐츠학회논문지
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• 제9권7호
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• pp.325-332
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• 2009

우리나라의 부동산거래는 매매당사자가 거래조건에 합의한 후 계약서를 작성한다 매수인은 매도인에게 계약금을 지급하고 잔금지급일과의 사이에 중도금을 지불 한 후 잔금지급과 등기이전서류를 동시에 교부하여 등기를 하는 방식으로 거래가 이루어지고 있다. 그러나 부동산거래는 계약일로부터 등기이전을 마칠 때까지의 사기, 횡령, 배임에 의한 이중매매 등 여러 가지 사고가 잠재되어 있다. 그럼에도 불구하고 매수인은 등기이전을 완료하기 전까지 정보의 비대칭으로 인하여 매도인에게 일방적으로 당하게 되어 있다. 이러한 책임 공백상태를 ESCROW제도를 이용하면 매도인의 배임에 의한 이중매매를 효과적으로 방지할 수 있을 것이다.

• ETRI Journal
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• 제40권6호
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• pp.736-744
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• 2018

This study considers zone-based registration (ZBR), which is adopted by most mobile cellular networks. In ZBR, a user equipment (UE) registers its location area (or zone) in a network database (DB) whenever it enters a new zone. Even though ZBR is implemented in most networks for a UE to keep only one zone (1ZR), it is also possible for a UE to keep multiple zones. Therefore, a ZBR with two zones (2ZR) is investigated, and some mathematical models for 2ZR are presented. With respect to ZBR with three zones (3ZR), several studies have been reported, but these employed computer simulations owing to the complexity of the cases, and there have been no reports on a mathematical 3ZR model to analyze its performance. In this study, we propose a new mathematical model for 3ZR for the first time, and analyze the performance of 3ZR using this model. The numerical results for various scenarios show that, as the UE frequently enters zones, the proposed 3ZR model outperforms 1ZR and 2ZR. Our results help determine the optimal number of zones that a UE keeps, and minimize the signaling cost for radio channels in mobile cellular networks.