CFD를 이용한 예배당에서의 COVID-19 집단감염 분석

박동준(Park, Dongjun),강경모(Kang, Kyungmo),김태연(Kim, Taeyeon) 한국생태환경건축학회 2021 한국생태환경건축학회 학술발표대회 논문집 Vol.21 No.2

Recently, there have been serious problems that were caused by the increasing cases of mass infection in public places. This research studies the specific outbreaks that occurred in a religious facility in Korea. CFD analysis uses the droplet nuclei diffusion method of the person who was infected the first. This study proves how indoor natural ventilation affects droplet concentration and airflow pattern. In conclusion, CFD analysis shows that the indoor airflow pattern affects the change in droplet concentration. In addition, natural ventilation reduces the droplet concentration by 21%.

실버세대 및 자율성 저하 노인을 위한 문화매개활동 연구 -프랑스어권 사례를 중심으로

박동준 ( Dongjun Park ) 연세대학교 유럽사회문화연구소 2016 유럽사회문화 Vol.0 No.16

Le guide se rattache au developpement d’approches de mediation culturelle destinees aux aines. Le guide de bonnes pratiques a ete realise dans le territoire de la Monteregie au Canada. Les personnes ainees : de qui parle-t-on? Il n’existe aucun consensus sur la definition d’une personne ainee. Dans une perspective de prevention et afin d’inciter a un vieillissement actif, on a besoin de certains moyens. L’art est en constante interaction avec la societe, la ou se tissent les liens entre politique, culture et espace public. Ce processus de mise en relation entre les spheres de la culture et du social est aussi connu sous le nom de mediation culturelle. On entend par activites de mediation culturelle des initiatives qui facilitent l’appropriation de la culture par les citoyens. Ces actions creent une opportunite de rencontres et d’echanges personnalises favorisant le contact des clienteles avec les oeuvres et les createurs. Elles permettent de faire le pont entre le citoyen et l’offre culturelle professionnelle. Les pratiques et les oeuvres artistiques dont il est question ici sont le fait de professionnels et ne doivent pas etre confondues avec celles relevant des loisirs culturels. Ainsi, les projets de mediation culturelle inities ou portes par des organismes ou des municipalites feront appel a des artistes ou a des travailleurs culturels professionnels. Dans la meme logique, il importe de comprendre la mediation culturelle comme un metier. a mesure que le champ de la mediation se concretise, les formations se developpent. Les mediateurs culturels developpent leurs competences en poursuivant des etudes universitaires ou en acquerant, comme artistes ou travailleurs culturels, une experience professionnelle.

Spatiotemporal Distribution of Dissolved Heavy Metals in Gyeonggi Bay, Korea

Sojung Park,최만식,Dongjun Jang,조동진,Kyunggue Park,Hyojin Lee,Junsik Woo,Taeha Kim,Jongkyu Park 한국해양과학기술원 2020 Ocean science journal Vol.55 No.1

In this study, we investigated the spatial and temporal distribution of heavy metals and nutrients in Gyeonggi Bay, Korea, to determine their present status and seasonal variability, and to identify their sources. Two surveys (May and August 2017) covering the entire Gyeonggi Bay (15 sites) and twelve surveys over four seasons (February, May, August, and November of 2016–2018) covering the Incheon Special Management Area (7 sites) were carried out to collect surface seawaters. Three surveys (January, April, and August of 2015) were also performed to collect seawater samples at Shihwa Lake (16 sites). Although the concentration gradients of nutrient type heavy metals (e.g. copper, nickel, zinc, and cadmium) corresponded to patterns of salinity in both dry and wet seasons, there was little seasonal variability over the three years studied. However, there was evidence that heavy metals were released during mixing with freshwaters in the wet season, likely from river outflow or direct coastal inputs such as effluents from Shihwa Lake. For nutrients, whereas the conservative mixing of dissolved inorganic nitrogen and the release of dissolved inorganic phosphate and dissolved silica were observed in the wet season, the concentrations of organic particles (e.g., chlorophyll-a, particulate organic carbon, and particulate organic nitrogen) had an inverse relationship with salinity in the dry season (May). Scavenged metals (e.g., manganese and cobalt) had non-freshwater coastal sources, such as benthic remobilization from suboxic sediments, and exhibited seasonal variation; they progressively increased in concentration from winter to spring and summer, and dropped to their minimum levels in the fall, which was presumably related to variation in microbial activity in sediments. Based on their relationship with salinity, heavy metals were deduced to be derived from coastal sources such as effluents from Shihwa Lake and freshwater from the Han River.

국내 도심지 학교 학생들의 BC(Black carbon) 흡입 노출량

박동준(Park, Dongjun),강경모(Kang, kyungmo),김태연(Kim, Taeyeon) 대한건축학회 2023 대한건축학회 학술발표대회 논문집 Vol.43 No.1

국내 학교 체육관의 실내 PM<SUB>2.5</SUB> 저감을 위한 CFD 분석 연구

박동준(Park, Dongjun),강경모(Kang, Kyungmo),김태연(Kim, Taeyeon) 한국생태환경건축학회 2021 한국생태환경건축학회 학술발표대회 논문집 Vol.21 No.1

Distribution and Sources of Dissolved and Particulate Heavy Metals (Mn, Co, Ni, Cu, Zn, Cd, Pb) in Masan Bay, Korea

Sojung Park,최만식,Dongjun Jang,조동진,Kyunggue Park 한국해양과학기술원 2020 Ocean science journal Vol.55 No.1

In this study, we investigated the spatial and temporal distribution and sources of dissolved and particulate heavy metals in Masan Bay, an area that for a long time has been contaminated by waste from surrounding large industrial complexes and metropolitan cities. Surface seawater samples from 16 sites around inner Masan Bay and offshore were collected over four survey periods (October 2015 and June, August, and November 2016). The spatial gradients of dissolved and particulate heavy metal concentrations generally overwhelmed the temporal variability, with a sharp decrease in metal concentrations, as well as salinity, with distance from the innermost site near the river mouth toward offshore. This tendency was maintained throughout all four survey periods. With the exception of zone I (sites 1–4), the concentrations of dissolved and particulate heavy metals showed little spatial variability, although possible sources of heavy metals, such as wastewater treatment plants (WWTPs; Dukdong and Jinhae), were located in the area. The main sources of several heavy metals would be the river water itself, as well as the release processes of river particles. Metalenriched biological particles from river water and WWTP effluent were the main contributors to the particulate metal concentrations during June and August; however, during October and November, the particulate metal concentrations were supplied by detrital particles similar to sediment. The contamination index was calculated using metal concentrations in offshore samples as the background concentrations. Mn, Co, and Zn contamination in zone I ranged from grade 3 to 5, indicating moderate to strong pollution conditions.

대단면 석회석 광산 갱도 내 국부선풍기 승압력 및 통기효과 비교 연구

박동준(Dongjun Park),강현호(Hyeonho Kang),이창우(Changwoo Lee) 한국암반공학회 2017 터널과지하공간 Vol.27 No.1

국내 지하 석회석 광산은 대부분 대단면 갱도로 개발되고 있으며 갱내통기는 주요 선풍기에 의한 통기방식보다는 자연통기 및 국부통기에 의존하고 있다. 국부통기는 국부선풍기와 풍관을 이용한 급배기 통기방식을 적용하고 있으나 대단면 갱도 특성과 갱내 굴진․운반장비의 디젤화에 따라 소요통기량이 대폭 증대하여 통기의 효율 및 경제성 확보가 주요과제로 대두되고 있다. 본 연구에서는 대단면 갱내 작업장 국부통기를 위한 선풍기 용량 최적화를 위하여 축류식 및 프로펠러 선풍기를 개발하여 갱내 승압력 및 통기효과를 비교 분석함을 목적으로 한다. Most of the local limestone mines are developed as large-opening underground mines, while mine ventilation is heavily dependent on the natural ventilation and auxiliary systems, rather than the mechanical ventilation system using main fans. The current auxiliary ventilation system with fan and ducting requires optimization since enhanced deployment of diesel equipment demands higher airflow rate and the associated cost is expected to be too excessive for the local mine operators. This paper aims at optimizing the fan capacity for the working site ventilation through comparing the fan pressure in the mine airway and the ventilation efficiency of an axial-flow fan and a propeller fan developed in this study.

참조 테이블 기반 스칼라 곱 알고리즘에 대한 충돌 특성을 이용한 향상된 수평상관분석

박동준(Dongjun Park),이상엽(Sangyub Lee),조성민(Sungmin Cho),김희석(HeeSeok Kim),홍석희(Seokhie Hong) 한국정보보호학회 2020 정보보호학회논문지 Vol.30 No.2

FBC(Fixed-Base Comb)는 사전계산된 참조 테이블을 활용하여 ECDSA(Elliptic Curve Digital Signature Algorithm) 서명 생성의 핵심 연산인 스칼라 곱을 효율적으로 연산하는 방법이다. FBC는 비밀정보에 의존하여 테이블을 참조하고 테이블의 값은 공개되어 있기 때문에 단일파형 부채널 공격 기법인 수평상관분석(HCA, Horizontal Correlation Analysis)에 의해 그 비밀정보가 드러날 수 있다. 그러나 HCA는 통계 분석의 일종으로 하나의 스칼라 곱 파형으로부터 충분한 수의 단위 연산 파형을 얻을 수 있어야만 공격에 성공할 수 있다. ECDSA 서명 생성에 쓰이는 스칼라 곱의 경우 RSA 거듭제곱에 비해 HCA에 이용 가능한 단위 연산 파형의 수가 현저히 적어 공격에 실패할 수 있다. 본 논문에서는 FBC와 같은 참조 테이블 기반 스칼라 곱에 대하여 향상된 HCA를 제안한다. 제안하는 기법은 충돌 분석으로 중간값이 같은 단위 연산 파형을 식별함으로써 공격에 이용되는 단위 연산 파형의 수를 증가시켜 HCA의 공격 성능을 향상시킨다. 제안하는 기법은 사용된 타원곡선 파라미터의 보안 강도가 높을수록 공격 성능이 향상하는 특징이 있다. The FBC(Fixed-Base Comb) is a method to efficiently operate scalar multiplication, a core operation for signature generations of the ECDSA(Elliptic Curve Digital Signature Algorithm), utilizing precomputed lookup tables. Since the FBC refers to the table depending on the secret information and the values of the table are publicly known, an adversary can perform HCA(Horizontal Correlation Analysis), one of the single trace side channel attacks, to reveal the secret. However, HCA is a statistical analysis that requires a sufficient number of unit operation traces extracted from one scalar multiplication trace for a successful attack. In the case of the scalar multiplication for signature generations of ECDSA, the number of unit operation traces available for HCA is significantly fewer than the case of the RSA exponentiation, possibly resulting in an unsuccessful attack. In this paper, we propose an improved HCA on lookup table based scalar multiplication algorithms such as FBC. The proposed attack improves HCA by increasing the number of unit operation traces by determining such traces for the same intermediate value through collision analysis. The performance of the proposed attack increases as more secure elliptic curve parameters are used.

도심지의 초등학교 교실 BC, PM<SUB>2.5</SUB> 원인 및 영향 분석

박동준(Park, Dongjun),강경모(Kang, kyungmo),김태연(Kim, Taeyeon) 대한건축학회 2022 대한건축학회 학술발표대회 논문집 Vol.42 No.2

실시간 UAV 중계를 위한 타임미러링 기반 DTDMA 프로토콜

이동준(Dongjune Lee),박진혁(Jinhyeok Park),임재성(Jaesung Lim),윤선희(Seonhui Yun),박형원(Hyungwon Park) 한국통신학회 2018 韓國通信學會論文誌 Vol.43 No.2