태평양 중심의 세계지도 제작을 위한 최적의 지도 투영법 선정

이상일,조대헌,이건학 한국지도학회 2012 한국지도학회지 Vol.12 No.1

본 연구의 목적은 태평양 중심의 세계지도 제작을 위한 최적의 투영법을 선정하는 것이다. 이 연구 목적을 달성하기 위해 투영법의 유형 분류와 투영법 선정의 가이드라인에 대한 기존 연구를 검토하였다. 최적의 투영법 선정을 위해 대중성 규준, 정적성 우위 혹은 절충성 규준, 그리고 왜곡 최소화 규준이 설정되었다. 이 세 규준을 적용한 결과 에케르트 IV 도법, 로빈슨 도법, 빈켈 트리펠 도법, 밀러 도법이 후보 투영법으로 선정되었다. 선정된 후보 투영법에 대한 면밀한 지도학적 평가와 비교 분석이 이루어졌으며, 지도학적 식견이 있는 사람들을 대상으로 사용자 선호도 조사가 실시되었다. 모든 사항을 종합적으로 판단한 결과 로빈슨 도법이 최종적인 투영법으로 선정되었다. 로빈슨 도법의 상대적 우위성은 중앙 경선이 본초 자오선인 경우보다 동경 150º 인 경우에 더 잘 드러나는 것으로 인정되었다. 로빈슨 도법의 변환 공식 도출과 관련된 학술적 논의를 바탕으로 투영 실행의 일반 원칙이 수립되었으며, 로빈슨 도법을 위한 가변 축척의 제작 절차가 제시되었다. The main objective of the paper is to seek to find the best map projection for a world map centered on the Pacific Ocean. To accomplish this objective, some classification schemes and selection guidelines for map projections are reviewed and then such criteria as popularity, equivalence or compromise, and minimum of overall distortion are established for the search. After evaluated on the basis of the criteria, four candidates are selected: Eckert IV, Robinson, Winkel Tripel, and Miller cylindrical projections. They are extensively investigated and compared in terms of their cartographic characteristics. A survey targeting cartographically informed people is undertaken to inquire into different preferences among the projections. It is concluded from all these that Robinson projection is the best one. The relative superiority of the projection is contended to be better seen when the central meridian is set on the 150º E rather than when it is on the prime meridian. With a through review on the derivation of transformation equations for the Robinson projection, a general principle of implementing the projection is established and a procedure of designing a variable scale bar suitable for it is presented.

Focus Projections in English, Korean, and Greek and Their Topological Implications

Jong-Bok Kim 현대문법학회 2003 현대문법연구 Vol.32 No.-

One of the important issues in information packaging theory is how to capture the projection of focus at sentence level. This paper shows that in three typological different languages (English: SVO, Korean: SOV, Greek: VSO), the order in argument structure (rather than linear order) plays an important role in determining various possibilities of inheritance of focus. This paper proposes that what is relevant for determining the possibility of VP focus in such cases is the argument structure ordered not in terms of theta-roles but in terms of grammatical relations. The need for such a level of argument structure gets strong motivations from phenomena such as binding, control, relativization, and so forth. Following this line, we assume that the argument structure with grammatical functions is ordered as SUBJ-OBJ-OBJ2-OBLIQUE in which if A precedes B in the argument-structure, A has a higher rank than (i.e. outranks) B. This comparative study among three typologically different languages reveals that the variations in the ordering of grammatical functions induce the differences in focus projections. In addition, the focus projections in the three languages support the view that the argument structure hierarchy is the locus of focus projection.

Effect of the Number of Projected Images on the Noise Characteristics in Tomosynthesis Imaging

Fukui, Ryohei,Matsuura, Ryutaro,Kida, Katsuhiro,Goto, Sachiko Korean Society of Medical Physics 2021 의학물리 Vol.32 No.2

Purpose: In this study, we investigated the relationship between the noise characteristics and the number of projected images in tomosynthesis using a digital phantom. Methods: The digital phantom consisted of a columnar phantom in the center of the image and a spherical phantom with a diameter of 80 pixels. A virtual scan was performed, and 128 projected images (Tomo_w/o) of the phantoms were obtained. The image noise according to the Poisson distribution was added to the projected images (Tomo_×1). Furthermore, another projected image with additional noise was prepared (Tomo_×1/2). For each dataset, we created datasets with 64 (half) and 32 (quarter) projections by removing the even-numbered images twice from the 128 (fully) projected images. Tomosynthesis images were reconstructed by filtered back projection (FBP). The modulation transfer function (MTF) was estimated using the sphere method, and the noise power spectrum (NPS) was estimated using the two-dimensional Fourier transform method. Results: The MTFs did not change between datasets, and the NPSs improved as the number of projected images increased. The noise characteristics of the Tomo_×1_half images were the same as those of the Tomo_×1/2_full. Conclusions: To achieve a reduction in the patient dose in tomosynthesis acquisition, we recommend reducing the number of projected images rather than reducing the dose per projection.

장래인구추계의 확정인구와 주민등록인구와 주민등록연양인구에 대한 비교연구

김종태(Jongtae Kim) 한국데이터정보과학회 2020 한국데이터정보과학회지 Vol.31 No.2

본 연구는 ‘장래인구추계 확정 인구 (PPP)’와 ‘주민등록인구 (RRP)’, ‘주민등록연양인구 (RRCP)’, 세 가지 인구통계의 문제점들을 찾고, 비교 분석하는 것에 목적이 있다. 연령상승인구를 출생연도별로 추적 조사한 결과, 최대값의 빈도수는 장래인구추계 > 주민등록인구 > 주민등록연앙인구의 순서이고, 연령상승인구의 최소값 빈도수 역시 장래 인구추계 > 주민등록인구 > 주민등록연장인구의 순서이었다. ‘연령상승인구’들에 대한 분산은 장래인구추계 > 주민등록인구 > 주민등록연앙인구의 순서로 나타난다. 전체적으로는 ‘주민등록연앙인구’는 ‘주민등록인구’나 ‘장래인구추계’ 보다는 연령상승 인구의 변화 관점에서 안정되어 있다. 향후의 연구에서는 본 연구를 기초로 ‘주민등록연앙인구’, ‘주민등록인구’, 그리고 ‘장래인구추계’에 대한 보정을 거친 데이터를 만들고, 신뢰할 수 있는 인구추계 데이터를 연구할 것이다. The purpose of this study is to find and compare the problems of three demographics, prospective population projections (PPP), resident registration population (RRP) and resident registration central population (RRCP). As a result of tracking the ’age-up population’ by birth year, the frequency of the maximum value is in order of prospective population projections > resident registration population > resident registration central population, and the minimum frequency of ’age-up population’ is also prospective population projections > resident registration population > resident registration central population. The variance of the ’age-up population’ appears in the order of prospective population projections > resident registration population > resident registration central population. Overall, resident registration central population is more stable in terms of changing ’age-up population’ than resident registration population or prospective population projections. Future research will use this study to generate data that have been calibrated for resident registration central population, resident registration population, and prospective population projections, and to study reliable population estimation data.

Nonnegative estimates of variance components in a two-way random model

Choi, Jaesung The Korean Statistical Society 2019 Communications for statistical applications and me Vol.26 No.4

This paper discusses a method for obtaining nonnegative estimates for variance components in a random effects model. A variance component should be positive by definition. Nevertheless, estimates of variance components are sometimes given as negative values, which is not desirable. The proposed method is based on two basic ideas. One is the identification of the orthogonal vector subspaces according to factors and the other is to ascertain the projection in each orthogonal vector subspace. Hence, an observation vector can be denoted by the sum of projections. The method suggested here always produces nonnegative estimates using projections. Hartley's synthesis is used for the calculation of expected values of quadratic forms. It also discusses how to set up a residual model for each projection.

영어, 한국어, 그리스어에서의 초점투사 현상 및 원리

김종복 현대문법학회 2003 현대문법연구 Vol.32 No.-

Jong-Bok Kim. 2003. Focus Projections in English, Korean, and Greek and Their Topological Implications. Studies in Modern Grammar 32, 1-23. One of the important issues in information packaging theory is how to capture the projection of focus at sentence level. This paper shows that in three typological different languages (English: SVO, Korean: SOV, Greek: VSO), the order in argument structure (rather than linear order) plays an important role in determining various possibilities of inheritance of focus. This paper proposes that what is relevant for determining the possibility of VP focus in such cases is the argument structure ordered not in terms of theta-roles but in terms of grammatical relations. The need for such a level of argument structure gets strong motivations from phenomena such as binding, control, relativization, and so forth. Following this line, we assume that the argument structure with grammatical functions is ordered as SUBJ-OBJ-OBJ2-OBLIQUE in which if A precedes B in the argument-structure, A has a higher rank than (i. e. outranks) B. This comparative study among three typologically different languages reveals that the variations in the ordering of grammatical functions induce the differences in focus projections. In addition, the focus projections in the three languages support the view that the argument structure hierarchy is the locus of focus projection.

기대수명의 연령별 사망률로의 전환에 대한 연구

김성용 한국자료분석학회 2019 Journal of the Korean Data Analysis Society Vol.21 No.3

UN released probabilistic population projections for all countries in 2014. Previously, age-specific populations are projected after predicting age-specific mortality rates, but in the new projection, the life expectancies at births of all countries are predicted by using the Bayesian hierarchical models, then converted to age-specific mortality rates by using the Lee-Carter model, leading age-specific population projections. The new method has the advantage of resolving the problems in forecasting life expectancies for each country because the relevance of life expectancy with other countries can be considered. However, it has been known that the Lee-Carter model used in this method has serious limitations such as the crossover of oldest-old mortality rates between sex, jump-off bias, and invariability of age effects. In this study, the conversion of life expectancy to age-specific mortality rates by using rotated Lee-Carter model is introduced, and applied to Korea mortality data. To this end, the mortality rates are extended to oldest-old ages and the new method is implemented. Finally, the appropriateness of the method to Korean mortality data is evaluated. UN에서는 2014년 전 세계 국가들에 대한 확률적 인구 추계를 발표하였다. 기존 인구추계에서는 연령별 사망률을 예측하고 이에 기반하여 연령별 인구를 예측한데 반해, UN에서는 전 세계 국가의 기대수명을 베이지안 계층 모델을 사용하여 예측하고 Lee-Carter 모형을 이용하여 이를 다시 연령별 사망률로 전환함으로써 연령별 인구를 예측하였다. 이와 같은 방법은 다른 국가와의 관련성을 통해 기대 수명을 예측함으로써, 개별 국가별 예측시 발생하는 문제점을 해결할 수 있는 장점이 있다. 그러나 Lee-Carter 모형의 경우 여러 문제점들이 지적되었는데, 초고령 사망률의 성별 교차문제, 점프 편의 문제 및 연령효과의 고정 등의 문제가 대표적이다. 따라서 Lee-Carter 모형을 이용하여 기대수명을 연령별 사망률로 전환할 경우, 여전히 이러한 문제에 봉착하게 된다. 본 연구에서는 최근 제안된 rotated Lee-Carter 모형을 이용한 기대수명의 연령별 사망률 전환 방법에 대해 소개하고, 이를 우리나라의 사망률 자료에 적용해보고자 한다. 이를 위해서 초고령 사망률의 확장을 수행하였으며, rotated Lee-Carter 모형을 이용한 방법론을 구현하여 해당 방법론의 우리나라 자료에의 적합성에 대해 파악하였다.

3D Model Retrieval Based on Orthogonal Projections

Wei, Liu,Yuanjun, He Society for Computational Design and Engineering 2006 International Journal of CAD/CAM Vol.6 No.1

Recently with the development of 3D modeling and digitizing tools, more and more models have been created, which leads to the necessity of the technique of 3D mode retrieval system. In this paper we investigate a new method for 3D model retrieval based on orthogonal projections. We assume that 3D models are composed of trigonal meshes. Algorithms process first by a normalization step in which the 3D models are transformed into the canonical coordinates. Then each model is orthogonally projected onto six surfaces of the projected cube which contains it. A following step is feature extraction of the projected images which is done by Moment Invariants and Polar Radius Fourier Transform. The feature vector of each 3D model is composed of the features extracted from projected images with different weights. Our System validates that this means can distinguish 3D models effectively. Experiments show that our method performs quit well.

자동조절자 내부점 방법을 위한 선형방정식 해법

설동렬 한국경영과학회 2004 經營 科學 Vol.21 No.2

Every iteration of interior-point methods of large scale optimization requires computing at least one orthogonal projection. In the practice, symmetric variants of the Gaussian elimination such as Cholesky factorization are accepted as the most efficient and sufficiently stable method. In this paper several specific implementation issues of the symmetric factorization that can be applied for solving such equations are discussed. The code called McSML being the result of this work is shown to produce comparably sparse factors as another implementations in the MATLAB environment. It has been used for computing projections in an efficient implementation of self-regular based interior-point methods, McIPM. Although primary aim of developing McSML was to embed it into an interior-point methods optimizer, the code may equally well be used to solve general large sparse systems arising in different applications.

자동조절자 내부점 방법을 위한 선형방정식 해법

설동렬 한국경영과학회 2004 經營 科學 Vol.21 No.3

Every iteration of interior-point methods of large scale optimization requires computing at least one orthogonal projection. In the practice, symmetric variants of the Gaussian elimination such as Cholesky factorization are accepted as the most efficient and sufficiently stable method. In this paper several specific implementation issues of the symmetric factorization that can be applied for solving such equations are discussed. The code called McSML being the result of this work is shown to produce comparably sparse factors as another implementations in the MATLAB*** environment. It has been used for computing projections in an efficient implementation of self-regular based interior-point methods, McIPM. Although primary aim of developing McSML was to embed it into an interior-point methods optimizer, the code may equally well be used to solve general large sparse systems arising in different applications.