• 한국컴퓨터그래픽스학회논문지
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• 제6권1호
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• pp.19-27
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• 2000

본 논문에서는 볼륨 데이터로부터 관심대상 객체의 3차원 경계면을 추출하고 이에 대한 기하학적 모델을 생성하기 위하여 자체교차방지 기능을 가진 다해상도 변형 모델을 제시한다. 변형 모델은 경계면 추출에 우수한 성능을 가진 것으로 알려져 있지만, 기존 변형 모델은 초기화 의존성, 오목한 경계면 추출의 취약성, 모델 요소간 자체교차 발생의 세가지 문제점을 가지고 있다. 제안하는 변형 모델은 다해상도의 볼륨 데이터를 기반으로하여 모델을 저해상도에서 고해상도로 세분화해가면서 객체의 경계면을 추출함으로서 초기화에의 의존성을 극복할 뿐 아니라 빠른 속도로 경계면에 수렴할 수 있다. 또한, 삼각형 메쉬 크기를 볼륨 데이터의 복셀 크기에 맞추어 항상 균일하게 유지함으로써 모델이 내부 힘의 제약없이 오목한 경계면을 성공적으로 추출할 수 있게 하였고, 모델이 변형될 때마다 자체교차방지 힘을 적용하여 모델내 삼각형 메쉬간의 자체교차를 사전에 방지할 수 있도록 하였다. 제안 모델을 컴퓨터 합성 볼륨 데이터 및 뇌 MR 볼륨 영상 데이터에 적용한 결과 오목한 함몰 부위를 가진 구와 뇌피질의 경계면을 자체교차없이 빠른 속도로 추출할 수 있었다.

• 대한기계학회논문집A
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• 제25권12호
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• pp.2009-2018
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• 2001

This paper presents a region offsetting algorithm for tool-path generation. The proposed region offsetting algorithm is developed by expanding the 'PWID offset algorithm [Choi and Park, 1999]'designed to offset a simple polygon. The PWID offset algorithm has three important steps; 1) remove 'local invalid ranges'by invoking a PWID test, 2) construct a raw offset owe and 3) remove 'global invalid ranges'by finding self-intersections of the raw offset cure. To develop a region offsetting algorithm, we modified the PWID offset algorithm by expanding the concept of the 'global invalid range'in the third step. The time complexity of the proposed algorithm is approximately Ο(n), where n is the number of points, and it is free of numerical errors for practical purposes. The proposed algorithm has been implemented and tested with various real regions obtained by intersecting a sculptured surface with a plane.

• Progress in Superconductivity
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• 제8권1호
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• pp.8-15
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• 2006

The size of the superconducting domains and the critical current density inside these domains have to be enhanced for most of cryomagnetic applications of melt-textured YBCO bulks. To enlarge the size of the domains we studied the multi-seeding technique based on a well-established procedure for preparing high quality YBCO monoliths using self-made SmBCO seeds. The distance between the seeds was optimised as a result of the investigation of the effects of various seed distances on the characteristics of the grain boundary Junctions. The influences of a-b plane intersections and c-axis misalignments were researched. Thereby, a small range of tolerance of the misorientations between the seed crystals was found. Field mapping was applied to control the materials quality and the superconductor's grain structure was investigated using polarisation microscopy. YBCO function elements with iou. seeds in a line and an arrangement of making type (100)/(100) and (110)/(110) boundary junctions, respectively, were processed. The trapped field profile in both sample types shows single domain behaviour. To demonstrate the potential of the multi-seeding method a ring-shaped sample was processed by placing sixteen seeds in a way to make both (100)/(100) and (110)/(110) grain junctions at the same time. The results up to now are very promising to prepare large single domain melt-textured YBCO semi-finished products in complex shapes.

• Journal of Computational Design and Engineering
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• 제3권2호
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• pp.151-160
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• 2016

Cutter-workpiece engagement (CWE) is the instantaneous contact geometry between the cutter and the in-process workpiece during machining. It plays an important role in machining process simulation and directly affects the calculation of the predicted cutting forces and torques. The difficulty and challenge of CWE determination come from the complexity due to the changing geometry of in-process workpiece and the curved tool path of cutter movement, especially for multi-axis milling. This paper presents a new method to determine the CWE for general milling processes. To fulfill the requirement of generality, which means for any cutter type, any in-process workpiece shape, and any tool path even with self-intersections, all the associated geometries are to be modeled as triangle meshes. The involved triangle-to-triangle intersection calculations are carried out by an effective method in order to realize the multiple subtraction Boolean operations between the tool and the workpiece mesh models and to determine the CWE. The presented method has been validated by a series of case studies of increasing machining complexity to demonstrate its applicability to general milling processes.

• 영어영문학
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• 제55권4호
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• pp.517-538
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• 2009

This study explores the possibility of finding intersections of commonness and differences between Mahasweta Devi's short stories, "The Hunt" and "Douloti the Bountiful" and Angela Carter's "Flesh and the Mirror" and "Master" in Fireworks. At appearance, Carter as a writer of Great Britains and Devi as a writer of India in postcolonial period do not seem to share any commonness. This study, however, tried to find "common differences," to quote Chandra Mohanty's terminology, as a basis of solidarity possible between these two different feminist writers. Another concept appropriated in this process of comparing Carter and Devi is Gayatri Spivak's 'planetary comparative literature,' which contends the necessity of critical regional studies and the study of Asian Literature in the study of English literature. Devi and Carter, despite their historical, geopolitical and racial differences, share commonness in depicting Asian or colonized women not only as the oppressed others but also as the subjects who show potential for resistance and independence. Carter portrays Japanese women as the colonized and oppressed others of Japanese society, even though Japan did not have any colonial history. Devi finds in the postcolonial Indian women both the oppressed in the interstice of colonial/postcolonial/patriarchal Indian history and the potential for resistance. Despite some limitation in her understanding of Asia, Carter shows her insight to accept Asia as a true origin of her self-knowledge and performativity of her woman's role. Despite their differences, these two writers use Freud's 'unheimlich' from the feminist point of view, in general. Devi's depiction of the heroine's dead body at the end of the story implicates the possibility of resistance through women's 'uncanny' bodies. Carter converts Freudian and negative connotation of woman's body into positive and comfortable 'home' as a starting point of her self knowledge.

• Asian review of World Histories
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• 제3권1호
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• pp.81-112
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• 2015

This essay interrogates the category of the 'global' in the emerging domain of 'global intellectual history'. Through a case study of the Indian social-religious reformer Rammohun Roy (1772/4-1833), I argue that notions of global selfhood and rights-consciousness (which have been preoccupying concerns of recent debates in intellectual history) have multiple conceptual and practical points of origin. Thus in early colonial India a person like Rammohun Roy could invoke centuries-old Indic terms of globality (vishva, jagat, sarva, sarvabhuta, etc.), selfhood (atman/brahman), and notions of right (adhikara) to liberation/salvation (mukti/moksha) as well as late precolonial discourses on 'worldly' rights consciousness (to life, property, religious toleration) and models of participatory governance present in an Indo-Islamic society, and hybridize these with Western-origin notions of rights and liberties. Thereby Rammohun could challenge the racial and confessional assumptions of colonial authority and produce a more deterritorialized and non-sectarian idea of selfhood and governance. However, Rammohun's comparativist world-historical notions excluded other models of selfhood and globality, such as those produced by devotional Vaishnava, Shaiva, and Shakta-Tantric discourses under the influence of non-Brahmanical communities and women. Rammohun's puritan condemnation of non-Brahmanical sexual and gender relations created a homogenized and hierarchical model of globality, obscuring alternate subaltern-inflected notions of selfhood. Class, caste, and gender biases rendered Rammohun supportive of British colonial rule and distanced him from popular anti-colonial revolts and social mobility movements in India. This article argues that today's intellectual historians run the risk of repeating Rammohun's biases (or those of Hegel's Weltgeschichte) if they privilege the historicity and value of certain models of global selfhood and rights-consciousness (such as those derived from a constructed notion of the 'West' or from constructed notions of various 'elite' classicized 'cultures'), to the exclusion of models produced by disenfranchised actors across the world. Instead of operating through hierarchical assumptions about local/global polarity, intellectual historians should remain sensitive to and learn from the universalizable models of selfhood, rights, and justice produced by actors in different spatio-temporal locations and intersections.

• 한국산학기술학회논문지
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• 제18권7호
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• pp.224-236
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• 2017

본 노인교통안전정책을 제시하기 위하여 경기지역에서 발생하고 있는 실제 지역유형별(도시지역, 도농복합지역, 농촌지역) 노인운전자의 교통사고 특성을 분석한 결과, 3개 지역 모두 안전운전의무 불이행에 의한 교통사고가 가장 많이 발생하는 것으로 나타났고, 도시지역과 도농복합지역은 신호위반과 교차로 사고, 그리고 농촌지역은 중앙선 침범에 의한 교통사고가 높은 것으로 나타났다. 도시지역과 도농복합지역은 신호운영에 있어서 오버랩 등 복잡한 신호운영보다는 단순한 양직진후 좌회전 또는 직진과 좌회전 동시신호 부여 등 단순한 신호 표출방안이 필요하다. 그리고 무신호교차로와 비보호교통신호 처리에 대한 개선이 필요하다. 게다가 농촌지역의 중앙선 침범사고를 예방하기 위하여 중앙선에 가드레일을 설치하여 중앙선 침범을 방지하고 반대방향 자동차 전조등에 의한 영향을 감소시켜야 하며, 해가 지는 일몰 시간대의 교통사고 예방을 위하여 운전 중에 파악해야 할 교통표지판 및 도로표지 등의 글자크기 확대와 형광글씨를 사용하여 시인성 개선해야 하며, 복잡한 문구와 여러 가지 정보보다는 단순화한 정보제공 문구와 최소의 정보제공으로 단순화해야 한다.

• 한국심리학회지 : 문화 및 사회문제
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• 제16권1호
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• pp.1-18
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• 2010

본 연구에서는 보행자 교통사고 조사자료 분석을 통해 고령보행자 사고가 가지는 특성을 알아보고, 증가추세에 있는 고령보행자 사망사고를 감소시킬 수 있는 방안을 모색하고자 하였다. 2005년부터 2008년까지 4년 동안 전국에서 발생한 보행자 사망사고 가운데 65세 이상 고령보행자가 피해를 입은 3,853건과 비교군 사고로 20세에서 44세 사이의 보행자 피해사건 1,786건의 특성을 비교하였다. 이들 두 집단의 사고특성을 각 항목별 점유율로 비교한 결과, 고령자의 사고는 대도시보다는 규모가 더 작은 지역에서 가을철에 특히 많이 발생하는 것으로 나타났으며, 고령보행자가 더 안전한 환경에서 보행행동을 하고자 하는 보상행동을 보이지만 실제로는 교통사고에 더 취약한 것으로 나타났다. 고령보행자는 청년기 보행자들에 비하여 도로횡단을 하는데 취약점을 드러내고 있었으며 특히 단순한 구조보다는 복잡한 도로구조에서 더 사고를 많이 겪는 것으로 확인되었다. 또한 차량과의 상충상황에 있어서는 좌우 방향으로 회전중인 차량이나 후진중인 차량에 상대적으로 더 위험을 겪고 있는 것으로 확인되었다. 이와 같은 고령보행자 사고의 특성은 고령자들의 연령증가에 따른 신체적·정신적 능력의 손실과 확신수준의 저하와 같은 심리적 상태에 의해 설명될 수 있다.