헤드 마운티드 디스플레이를 위한 시간 제약 렌더링을 이용한 적응적 포비티드 광선 추적법

김영욱,임인성 (사)한국컴퓨터그래픽스학회 2022 컴퓨터그래픽스학회논문지 Vol.28 No.3

Ray tracing-based rendering creates by far more realistic images than the traditional rasterization-based rendering. Howeve r, it is still burdensome when implemented for a Head-Mounted Display (HMD) system that demands a wide field of view and a high display refresh rate. Furthermore, for presenting high-quality images on the HMD screen, a sufficient number of ray sampling should be carried out per pixel to alleviate visually annoying spatial and temporal aliases. In this paper, we e xtend the recent selective foveated ray tracing technique by Kim et al. [1], and propose an improved real-time rendering tec hnique that realizes the rendering effect of the classic Whitted-style ray tracing on the HMD system. In particular, by comb ining the ray tracing hardware-based acceleration technique and time-constrained rendering scheme, we show that fast HMD ray tracing is possible that is well suited to human visual systems. 광선 추적 기반의 렌더링은 래스터화 기반의 렌더링보다 훨씬 더 사실적인 이미지를 생성한다. 하지만 넓은시야와 높은 디스플레이 갱신 속도를 요구하는 헤드 마운티드 디스플레이(HMD) 시스템을 대상으로 이를 구현할 때에는 여전히 많은 연산량으로 인하여 부담스럽다. 또한, HMD 화면에 고품질 이미지를 표시하기 위해서는시각적으로 성가신 공간적/시간적 앨리어스를 줄이기 위해 픽셀당 충분한 수의 광선 샘플링을 수행해야 한다. 본 논문에서는 최근 Kim 등[1]이 제시한 선택적 포비티드 광선 추적법을 확장하여 주어진 HMD 시스템에서 고전적인 Whitted-스타일 광선 추적 수준의 렌더링 효과를 효율적으로 생성해주는 실시간 렌더링 기법을 제안한다. 특히, GPU의 광선 추적 하드웨어를 통한 가속과 시간 제한을 둔 렌더링 방법의 결합을 통하여 고속의HMD 광선 추적에 적합한 사람의 시각 시스템에 매우 효율적인 적응적 광선 샘플링 방법을 제안한다.

실시간 전역조명을 위한 프리미티브와 복셀 기반의 하이브리드 추적 기법

석예찬(Yechan Seok),이성길(Sungkil Lee) Korean Institute of Information Scientists and Eng 2021 정보과학회논문지 Vol.48 No.7

The voxel cone tracing algorithm based on the sparse octree stores indirect lighting attributes in a volume, and efficiently traces the volume for indirect illumination and reflections. However, as the volume resolution becomes higher, the amounts of memory and performance overhead significantly increase for the voxel cone tracing. In this paper, we propose a hybrid octree data structure, where sparse leaf nodes use primitive lists while dense leaf nodes still use voxels, and a hybrid tracing algorithm that adaptively performs the cone tracing and ray tracing. Our real-time solution outperforms the existing voxel cone tracing algorithm for high-quality indirect illumination.

사례연구와 과정추적법(process tracing): 새로운 인과관계 추론논리

황태연,정규진,이명석 한국행정학회 2019 韓國行政學報 Vol.53 No.4

This study (i) reviewed the significance and inferential logic of the process tracing method, which has recently been noted as a causal analysis method in the field of social science, such as in political science; (ii) analyzed trends in prior research using the process tracing method; and (iii) discussed the utility that the process tracing method may have in the field of Public Administration studies. The process tracing method is distinguished from traditional qualitative research based on the logic of quantitative research that KKV presented in the 1990s in that it is based on the reasoning of Bayesianism. It is expected that the various application possibilities of the process tracing method in the inference of causality will greatly contribute to the improvement of the quality of case studies in the field of Public Administration. 본 연구는 최근 정치학 등 사회과학 분야에서 인과관계 분석방법으로 주목받고 있는 과정추적법(process tracing)의 의의와 추론 논리를 검토하고, 과정추적법을 활용한 선행연구의 동향을 분석하고, 과정추적법이 행정학 연구에서 가질 수 있는 효용에 대해 논의하였다. 과정추적법은 베이즈주의 추론논리에 기반을 둔다는 점에서 1990년대에 KKV가 제시했던 양적연구의 논리에 기초하는 질적연구와 구별된다. 인과관계의 추론에서 과정추적법이 갖는 다양한 활용가능성은 행정학 사례연구의 질적 향상에 크게 기여할 수 있을 것으로 기대된다.

Perceived usefulness of COVID-19 tools for contact tracing among contact tracers in Korea

Gong Seon Yeong,Moon Jong Youn,Jung Jaehun 한국역학회 2022 Epidemiology and Health Vol.44 No.-

OBJECTIVES: In Korea, contact tracing for coronavirus disease 2019 is conducted using the information from credit card records, handwritten visitor logs, KI-Pass (QR code), and Safe Call after an interview. We aimed to assess the usefulness of these tools for contact tracing. METHODS: The 2 months (July to September 2021) long anonymous online survey was conducted. Contact tracers from throughout Korea were included as the participants. The questionnaire consisted of 4 parts: 1) demographic characteristics, 2) usefulness of each tool for contact tracing, 3) order in which information is checked during contact tracing, and 4) match rate between tools for contact tracing, screening test rate, response rate, and helpfulness (rated on a Likert scale). RESULTS: A total of 190 individuals participated in the survey. When asked to rate the usefulness of each tool for contact tracing on a Likert scale, most respondents (86%) provided positive response for “credit card records”, while the most common response for “handwritten visitor logs” was negative. The actual helpfulness of positive response was KI-Pass (91%), Credit card records (83%), Safe Call (78%), and Handwritten visitor logs (22%). CONCLUSIONS: Over 80% of participants provided positive responses to credit card records, KI-Pass, and Safe Call data, while approximately 50% provided negative responses regarding the usefulness of handwritten visitor logs. Our findings highlight the need to unify systems for contact tracing performed after an interview to increase their convenience for contact tracers, as well as the need to improve tools that utilize handwritten visitor logs for digitally vulnerable groups.

Earthworm effects on soil biogeochemistry in temperate forests focusing on stable isotope tracing: a review

Kim Gaeun,Jo Heejae,Kim Hyung-Sub,Kwon Minyoung,Son Yowhan 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.6

Earthworms (Oligochaeta) are globally distributed soil-dwelling invertebrates that alter soil properties through feeding, casting, and burrowing behaviors. Soil physicochemical modification, which may directly influence the availability and dynamics of organic and inorganic nutrients in the soil, such as carbon and nitrogen, includes soil texture, porosity, and pH. Temperate forests produce year-round plant litter, the primary food source for earthworms, and litter processed by earthworms significantly contributes to soil organic material storage. In recent decades, studies on temperate forest ecosystems have attempted to elucidate and quantify the earthworm impact on soil organic material dynamics, mainly targeting carbon and nitrogen, using isotope analysis methods. This paper summarizes studies on the following topics: (1) effect of earthworm modification on soil property to understand these alterations’ interaction with carbon and nitrogen dynamics, and (2) isotope tracing method, used to elucidate the earthworm effect on carbon and nitrogen transformation and movements in temperate forests. The particular emphasis on the isotope method is based on its capability of time-adjusted quantification of organic materials in the ecosystem compartments. Also, isotopic labeling in biomass has a broad range of applications, such as tracing assimilated food sources, identifying trophic interactions in soil food webs, and addressing material dynamics in complex linkages between earthworms and their environment. In addition, we provide perspectives on other methodologies, such as chronology and population ecology, as feasible options to further assist the isotope tracing of earthworms’ impact on soil nutrient dynamics. Earthworms (Oligochaeta) are globally distributed soil-dwelling invertebrates that alter soil properties through feeding, casting, and burrowing behaviors. Soil physicochemical modification, which may directly influence the availability and dynamics of organic and inorganic nutrients in the soil, such as carbon and nitrogen, includes soil texture, porosity, and pH. Temperate forests produce year-round plant litter, the primary food source for earthworms, and litter processed by earthworms significantly contributes to soil organic material storage. In recent decades, studies on temperate forest ecosystems have attempted to elucidate and quantify the earthworm impact on soil organic material dynamics, mainly targeting carbon and nitrogen, using isotope analysis methods. This paper summarizes studies on the following topics: (1) effect of earthworm modification on soil property to understand these alterations’ interaction with carbon and nitrogen dynamics, and (2) isotope tracing method, used to elucidate the earthworm effect on carbon and nitrogen transformation and movements in temperate forests. The particular emphasis on the isotope method is based on its capability of time-adjusted quantification of organic materials in the ecosystem compartments. Also, isotopic labeling in biomass has a broad range of applications, such as tracing assimilated food sources, identifying trophic interactions in soil food webs, and addressing material dynamics in complex linkages between earthworms and their environment. In addition, we provide perspectives on other methodologies, such as chronology and population ecology, as feasible options to further assist the isotope tracing of earthworms’ impact on soil nutrient dynamics.

코로나바이러스감염증-19 역학조사에 대한 비례 원칙의 고찰

박미정(Mijeong PARK) 이화여자대학교 생명의료법연구소 2021 Asia Pacific Journal of Health Law & Ethics Vol.14 No.2

한국의 코로나바이러스감염증-19 역학조사는 직접 면담을 하는 심층역학조사와 수집된 정보를 활용하는 밀접 접촉자 추적조사로 구분된다. 역학조사의 정확성과 감염경로를 추적하기 위하여 개인정보나 이동통신사 기지국 위치정보 등을 활용하고 있다. 이러한 정보를 수집하고 활용하는 것이 정당화 되려면 감염병 예방법이라는 특별법에 근거하여야 한다. 법률에 근거한 기본권제한은 헌법 제37조 제2항에 명시된 국가 안전보장·질서유지 또는 공공복리를 위하여 필요한경우에 가능하다. 코로나바이러스감염증-19 역학조사 방법이 헌법이 선언한 비례 원칙에 합치하는지 분석하기 위하여 정보 공개를 위한 법률의 구체성, 정보제공 요청의 정당성, 긴급한 행정 조사로써 적법한 절차를 고찰하였다. 연구대상은 지방자치단체의 확진 환자 동선 정보 공개사례, 대구·경북지역 감염 발생 대응에서 신천지 교인 명단의 요청사례, 그리고 서울 이태원지역 집단감염 발생 대응에서 기지국 위치정보 활용사례다. 비례 원칙의 형식 요건 분석 결과, 감염병 예방법에 의하면 정보 공개 주체는 보건복지부장관으로 한정하고 있으며, 집단 발생 관련 ‘반복 대량 노출 장소’는 중앙방역대책본부에서 공개하므로 지자체에서 공개하지 않도록 하고 있다. 지자체의 정보 공개는 법적 근거를 우회하는 측면에서 프라이버시 침해의 소지가 있다고 보았다. 지자체가 감염병 발생 정보를 공개해야 한다면, 하위 법령에서 근거를 마련하는 것이 바람직하다. 목적 요건 분석 결과, 역학조사 목적에 필수적인 정보를 개인정보로 분리함으로써 변경되는 기본권을 지목하지 않는 한, 그 목적이 정당하다고 보았다. 방법 요건 분석 결과, 서울 이태원 지역의 기지국 위치추적자료는 제공 목적에 부합하게 역학조사를 위하여 사용되었다고 보았다. 다만 위치추적자료의 요청은 예외적인 행정 조사의 특성을 포괄하고 있어 감염병 예방법에서 정보제공과 정보 처리를 위한 적법한 절차를 규정하는 것이 필요하다. 역학조사는 공공의 이익을 목적으로 개인정보를 활용하되 프라이버시 보호를 위한 최소 침해적인 수단을 통해서 구현해야 하는 양면성이 있음을 고찰하고, 역학조사 방법과 관련된 법률조항의 개선방안을 제안하였다. The contact tracing of COVID-19 in Korea is divided into “in-depth epidemiological investigation” which targets the infected patient and “contact investigation”, which gathers data from close contacts. Personal information and automatically collected location information directly from the patient were used for contact tracing. To justify the data collected through contact tracing and use of personal information, epidemiological investigations should be based on a special law called the “Infectious Disease Prevention Act”. Article 37 (2) of the Constitution should also be considered, as it provides conditional restriction of basic rights to be allowed only when national security, public order or public welfare are at stake. But it should also be considered, that there are boundaries to be upheld, due to its personal privacy and rights violation. The purpose of this article is to analyze whether the COVID-19 contact tracing methods comply to the principle of proportionality declared by the Korean Constitution. The assessment was conducted considering three essential prerequisites for conforming to the Constitution, which are as follows, Format, Purpose, and Method. Legal format for information disclosure was assessed for Format prerequisites, Legitimacy of the request for information provision for Purposes prerequisites, and lastly, the least invasive means that balances the public good and private interests were analyzed for Method prerequisites. The target of this study are the cases of infected people’s travel logs information disclosure by local governments, and the Central Disease Control Headquarters’s request for the list of the whole congregation of the member of “ShinCheonJi” denomination during the outbreak, and the “Itaewon” cluster’s outbreak using GPS data collected by telecommunication stations. According to the analysis of the format requirements, the laws enforcing infectious disease prevention dictate that the subject of information disclosure should be limited to the head of the Ministry of Health and Welfare, and the Central Disease Control Headquarters. The Central Disease Control Headquarters discloses “repeated mass exposure locations” related to cluster outbreaks. Thus, the local governments are not empowered or allowed to disclose them. Administrative measures of local governments that prioritize the prevention and control of infectious diseases are subject to violation of personal privacy. According to the analysis of purpose requirements, the list of the whole congregation of Shincheonji was requested in order to adequately respond to the super-spreading event of the virus. Considering the fact that investigation was able to be initiated meets the objective prerequisites. According to the result of the method requirements analysis, the GPS data of the people associated with the Itaewon outbreak in Seoul was collected without the consent of the subjects. However, this particular case encompasses exceptional characteristics of administrative investigations, thus it is necessary to stipulate legitimate procedures for information provision and information processing within the infectious disease prevention Act. Contact tracing methods are comprised of two objectives, minimally invasive measures and prolific data utilization, which determines it to be intrinsically ambivalent. Thus, this study proposes an amendment to the provisions related to the Legislation of contact tracing in order to adjust the arbitrary and strained equilibrium that arises between Public health and Privacy when proceeding investigations.

Lineage Tracing: Computational Reconstruction Goes Beyond the Limit of Imaging

Szu-Hsien Wu,이지현,구본경 한국분자세포생물학회 2019 Molecules and cells Vol.42 No.2

Tracking the fate of individual cells and their progeny through lineage tracing has been widely used to investigate various biological processes including embryonic development, homeostatic tissue turnover, and stem cell function in regeneration and disease. Conventional lineage tracing involves the marking of cells either with dyes or nucleoside analogues or genetic marking with fluorescent and/or colorimetric protein reporters. Both are imaging-based approaches that have played a crucial role in the field of developmental biology as well as adult stem cell biology. However, imaging-based lineage tracing approaches are limited by their scalability and the lack of molecular information underlying fate transitions. Recently, computational biology approaches have been combined with diverse tracing methods to overcome these limitations and so provide high-order scalability and a wealth of molecular information. In this review, we will introduce such novel computational methods, starting from single-cell RNA sequencing-based lineage analysis to DNA barcoding or genetic scar analysis. These novel approaches are complementary to conventional imaging-based approaches and enable us to study the lineage relationships of numerous cell types during vertebrate, and in particular human, development and disease.

Research on Parallel KD-Tree Construction for Ray Tracing

Zhang Peicheng,Xu Huahu,Bian Minjie,Honghao 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.11

Many computer graphics rendering algorithms and techniques use ray tracing for generation of photo-realistic images, and kd-tree is the most popular acceleration data structure for ray tracing. In order to avoid the inefficient parallel performance of kd-tree construction based on surface area heuristic (SAH), an algorithm using Morton code and path compression was present in this paper. Instead of building a kd-tree layer-by-layer, the proposed approach can be performed in parallel from bottom of a conceptual perfect binary tree. Experimental results on GPU show that our work achieves a faster kd-tree construction procedure.

Lineage Tracing: Computational Reconstruction Goes Beyond the Limit of Imaging

Wu, Szu-Hsien (Sam),Lee, Ji-Hyun,Koo, Bon-Kyoung Korean Society for Molecular and Cellular Biology 2019 Molecules and cells Vol.42 No.2

Tracking the fate of individual cells and their progeny through lineage tracing has been widely used to investigate various biological processes including embryonic development, homeostatic tissue turnover, and stem cell function in regeneration and disease. Conventional lineage tracing involves the marking of cells either with dyes or nucleoside analogues or genetic marking with fluorescent and/or colorimetric protein reporters. Both are imaging-based approaches that have played a crucial role in the field of developmental biology as well as adult stem cell biology. However, imaging-based lineage tracing approaches are limited by their scalability and the lack of molecular information underlying fate transitions. Recently, computational biology approaches have been combined with diverse tracing methods to overcome these limitations and so provide high-order scalability and a wealth of molecular information. In this review, we will introduce such novel computational methods, starting from single-cell RNA sequencing-based lineage analysis to DNA barcoding or genetic scar analysis. These novel approaches are complementary to conventional imaging-based approaches and enable us to study the lineage relationships of numerous cell types during vertebrate, and in particular human, development and disease.

온라인 저작권 침해 추적과 개인정보보호

김병일(Kim Byung Il) 한국정보법학회 2009 정보법학 Vol.13 No.3

최근 인터넷 기술 등의 발달로 포털사이트의 카페나 블로그에서의 불법링크, P2P (Peer to Peer) 사이트, 웹하드 사이트를 통한 저작권 침해가 광범위하게 확산되고 있다. 정부 및 저작권자들은 불법저작물 추적시스템을 이용하여 온라인상에서의 불법저작물 유통을 근절시키기 위한 노력을 경주하고 있다. 그런데, 불법저작물 추적을 위하여 최근 이용되고 있는 핑거프린팅 기술은 개인정보보호와 관련된 민감한 문제를 야기할 수 있다는 문제점이 나타날 수 있다. 또한 개인정보문제는 한미FTA 및 한-EU FTA 국내에 따라 정보제공청구권이 새로이 규정되는 경우에는 더욱 큰 문제점을 초래할 수 있을 것이다. 또한 불법 다운로드(illegal downloding)를 명시적으로 금지하는 경우에는 불법저작물 추적시스템을 통하여 수집된 개인정보가 오용될 가능성도 존재한다. 본 글에서는 불법저작물 추적기술에 대해 간단히 살펴보고, 정보제공청구권(right of information) 국내입법시 고려해야 하는 점을 개인정보 보호 관점에서 검토하고자 한다. Traitor tracing is a copyright infringement detection system which works by tracing the source of leaked files rather than by direct copy protection. Traitor tracing is a technique used to help combat copyright infringement. Legal enforcement of existing or new copyright laws is made enormously harder by the Internet and other new communications technologies. These technologies such as P2P file sharing allow information to be shared freely. Concerned about the consequences of illegal copying and distribution on a massive scale, content owners are interested in introducing for “traitor tracing” of copyright infringement. However, the system cause to conflict with “personal data protection”. Thus, this study aims to offer a better understanding of the legal issues related to current “traitor tracing” of copyright infringement and “personal data protection”. US law also includes a provision that enables copyright owners to issue a subpoena to an OSP to obtain identifying information in relation to a user who is alleged to be infringing copyright. The KORUS FTA does not require the implementation of a subpoena provision in Korea, but it does require that the Government make available an “expeditious” procedure to obtain this identifying information. This article therefore focuses on implementation of KORUS FTA in relation to the “right of information”.