내장형 자바 시스템을 위한 클라이언트 선행 컴파일 기법을 이용한 코드 캐시 확장

홍성현(Sunghyun Hong),김진철(Jin-Chul Kim),신진우(Jin Woo Shin),권진우(Jin-Woo Kwon),이주환(Joohwan Lee),문수묵(Soo-Mook Moon) 한국정보과학회 2010 정보과학회 컴퓨팅의 실제 논문지 Vol.16 No.8

많은 내장형 자바 시스템들이 제한된 메모리를 가지고 있으므로 JITC를 위해 충분한 코드 캐시가 주어지지 않아 자바의 수행 성능이 떨어질 수 있다. 본 논문에서는 이를 극복하고자 수행 중에 코드 캐시 공간이 부족하면 일부 메소드의 머신 코드를 영구적 메모리의 파일 시스템에 저장해 두었다가 재호출 때에 다시 코드 캐시로 읽어와서 재활용하는 코드 캐시를 확장하는 수행 방식을 제안한다. 이는 기존의 클라이언트 선행 컴파일 기법을 수행 중에 코드 캐시 확장을 위해 적용한 것이다. 우리가 제안한 자바 수행 구조는 코드 캐시가 반으로 줄었을 때의 일반적인 자바 수행 방식보다 1.6배 좋은 성능을 보여주고 있다. Many embedded Java systems are equipped with limited memory, which can constrain the code cache size provided for Java just-in-time compilation, affecting the Java performance. This paper proposes expanding the limited code cache when it is full, by saving the machine code for some methods in the code cache into the file system of the permanent storage and reloading it to the code cache when they are re-invoked later. This is applying the client ahead-of-time compilation during the execution time for the purpose of enlarging the code cache. Our experimental results indicate that the proposed execution method can improve the performance by as much as 1.6 times compared to the conventional method, when the code cache size is reduced by half.

강수지표를 이용한 우리나라 강수량의 시간적인 특성 변화

홍성현,김영규,이원현,정은성,Hong, Seong-Hyun,Kim, Young-Gyu,Lee, Won-Hyun,Chung, Eun-Sung 한국수자원학회 2012 한국수자원학회논문집 Vol.45 No.4

본 연구에서는 과거에서부터 기록된 우리나라 65개의 관측소들을 대상으로 강수량 데이터를사용하여 강수빈도와 극한 지표들을 산출해 냄으로써, 지표에 따라 지역별 분포를 살펴보고 시공간적인 증 감율에 대한 결과를 제시하였다. 그 결과를 시계열로 도시함으로 쉽게 파악할 수 있지만경향이 뚜렷하게 나타나지 않는 경우에는 통계적 방법인 Mann-Kendall 경향성 분석을 실시하여 이에 대해 파악하였다. 더불어 FARD를 이용하여 100년과 200년의 빈도확률강수량을 산정하고 이를 비교하였다. 강우특성을 크게 Amount, Extreme, Frequency로 분류하고 각각의 지수를 강우량 지수(Rainfall Index for Amount), 강우극치 지수(Rainfall Index for Extremes), 강우빈도 지수(Rainfall Index for Frequency)로 정의하고 RIA, RIE, RIF를 산술평균하여 홍수에 대한 종합적인 강우 위험도를 나타내는 평균 강우지수(Average Rainfall Index, ARI)를 산정하였다. 그 결과 과거에 비해 최근 10년간 강우량의 정량적인 평가 특성은 양적으로 22.3%, 극치사상 발생측면은 26.2%, 빈도측면은 5.1% 증가하였음을 확인 할 수 있었다. 본연구의 결과는 최근 우리나라 기후변화 경향을 구체적으로 제시하고 있으므로 기후변화 대비 적응 연구의 기초 자료로 활용될 수 있다. This study suggests the results of temporal and spatial variations for rainfall data in the Korean Peninsula. We got the index of the rainfall amount, frequency and extreme indices from 65 weather stations. The results could be easily understood by drawing the graph, and the Mann-Kendall trend analysis was also used to determine the tendency (up & downward/no trend) of rainfall and temperature where the trend could not be clear. Moreover, by using the FARD, frequency probability rainfalls could be calculated for 100 and 200 years and then compared each other value through the moment method, maximum likelihood method and probability weighted moments. The Average Rainfall Index (ARI) which is meant comprehensive rainfalls risk for the flood could be obtained from calculating an arithmetic mean of the RI for Amount (RIA), RI for Extreme (RIE), and RI for Frequency (RIF) and as well as the characteristics of rainfalls have been mainly classified into Amount, Extremes, and Frequency. As a result, these each Average Rainfall Indices could be increased respectively into 22.3%, 26.2%, and 5.1% for a recent decade. Since this study showed the recent climate change trend in detail, it will be useful data for the research of climate change adaptation.

표준진단표를 통해 본 시설채소 농가의 기술 및 경영 수준 변화

홍성현(Song-Hyun Hong),손찬수(Chan-Soo Son),박주섭(Joo-Sub Park),이상영(Sang-Young Rhee) 한국원예학회 2013 한국원예학회 학술발표요지 Vol.2013 No.5

개별 블레이드 피치제어를 이용한 고속 복합형 동축로터 회전익기의 진동억제 및 성능향상 연구

홍성현(Seong Hyun Hong),김동균(Dong Kyun Kim),정성남(Sung N Jung) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.4

메타버스 기반 가상박물관의 사례 분석을 통한 교육적 활용 방안 연구 : 국립중앙박물관 어린이박물관을 중심으로

홍성현(Hong, Seonghyeon) 국립중앙박물관 2022 박물관 교육 Vol.6 No.-

As social distancing was implemented to prevent the spread of COVID-19. many activities were moved online. Accordingly, various technologies were used to effectively connect people, and the metaverse drew attention, which is a fusion of the real world and the virtual world. As non-face-to-face activities gradually expanded in museums, interest and demand for virtual museums using the metaverse as an environment that could replace the physical space expanded, and various attempts were made to utilize the metaverse. The virtual museum has evolved with the development of the Web and is currently facing a new environment called Web 3.0. On the other hand, the metaverse is evaluated to have the conditions to implement the technical characteristics of Web 3.0. In addition, the metaverse can provide new experiences to learners by overcoming the limitations of monotonous interaction and adding interesting. This confirms the potential of the metaverse as the future of the virtual museum. Therefore, this study attempted to reveal the educational characteristics of the metaverse based on the Web 3.0 as a new environment for the virtual museum to move forward. In addition, the prpose was to confirm the process and phenomenon of the development and operation of the metaverse-based virtual museum through the analysis of a case and to propose methods of educational use as a result of the analysis. For this purpose, the case of ‘Untact Children’s Museum Virtual Exhibition’ of the Children’s Museum of the National Museum of Korea, was used. For an educational use centered analysis, the case was examined based on the educational characteristics of the metaverse-based virtual museum that are related to the characteristics of constructivist teaching and learning. The educational utilization plan of the metaverse-based virtual museum derived as a result is as follows. First, by using digital archives to faithfully reproduce elements of reality on the metaverse, or depict realistic virtual elements to enhance the completeness of the space, and by creating a situation that takes place through the s pace in detail, it enhances the learner’s sense of reality and induces immersion. Second, by using elements such as avatars and NPCs or by constructing a dynamic space, interaction is induced and a cooperative learning environment is provided. Third, through individualization, learning contents that learners may need and be interested in and activities appropriate to them are supported. This study is meaningful in that it examines the relationship between the metaverse and virtual museums, which was not revealed in previous studies, from the perspective of constructivist teaching and learning, and suggests ways to use them through educational characteristics and case analysis of the metaverse-based virtual museums as an educational environment suitable for the post-COVID-19 era. It is expected that the metaverse-based virtual museum can be used in various educations from a more expansive perspective in the direction of narrowing the physical distance between the museum and the learner and effectively supporting offline learning.

V8 자바스크립트 엔진을 위한 클라이언트 선행컴파일러

홍성현(Hong SungHyun),유영호(Yoo Young-ho),이성원(Lee Seong-Won),문수묵(Moon Soo-Mook) 한국정보과학회 2012 한국정보과학회 학술발표논문집 Vol.39 No.2A

로지스틱 회귀분석을 이용한 향토음식점의 선택속성에 관한 연구

홍성현 ( Song Hyun Hong ),최승철 ( Seung Churl Choi ) 한국축산경영학회 2012 농업경영정책연구 Vol.39 No.2

This study aims to examine the consumers` selection attributes and types of preference regarding native food restaurants, and gather useful information for establishing differentiated marketing strategies suitable for market segments by the selection attributes. In addition, it will contribute to securring competitiveness in providing consumers with better service by extracting differentiating factors and locations of native food restaurants, and exploring the right direction of native food industry. For the empirical analysis, the attributes were extracted based on the preliminary studies, and a survey was conducted among users of native food restaurants to examine such facotrs as importance of selection attributes status, motives of using such restaurants, demographic characteristics, and general features of the restaurants.

표준진단표를 통해 본 노지채소 농가의 기술 및 경영 수준 변화

홍성현(Song-Hyun Hong),손찬수(Chan-Soo Son),박주섭(Joo-Sub Park),이상영(Sang-Young Rhee) 한국원예학회 2013 한국원예학회 학술발표요지 Vol.2013 No.5

매미허물에서 분리한 키틴의 물리화학적 특성

홍성현 ( Seong Hyun Hong ),조경현 ( Gyung Hyun Jo ),주완택 ( Wan Taek Ju ),박노동 ( Ro Dong Park ) 한국키틴키토산학회 2010 한국키틴키토산학회지 Vol.15 No.2

매미 허물로부터 화학적 처리법으로 키틴을 분리하고 그 물리화학적 특성을 조사하였다. 얻어진 키틴은 백색의 분말 형태였으며 그 수율은 31.7%였다. 매미 키틴은 30℃에서 진한 염산 가수분해 반응으로 올리고당으로 분해되었으며, 반응시간에 따라 키틴의 분해율은 증가하여 24시간에는 44.0%의 분해율을 기록하였다. GlcNAc1-3의 함량 비율은 반응 0.5시간에 66.5%, 반응 12시간에는 84.4%로 증가하였다. 반응 24시간에는 단당 GlcNAc의 함량이 79.4%를 차지하였으며, 4당 이상은 검출되지 않았다. 매미허물 키틴은 게, 새우 키틴과 같은 형태의 FT-IR 스펙트럼 양상이 나타나 α-chitin으로 확인되었고, 아세틸화도는 88.1%로 조사되었다. 매미 허물 키틴의 X-선 회절 분석결과 2θ = 9.4˚, 19.4˚에서 면간격이 9.39 Å와 4.60 Å로 각각 측정되었으며, 결정화도 및 결정크기의 값은 각각 81.9%, 4.6 nm로 α-chitin인 게, 새우 키틴의 특성치와 유사하였다. In this study, the physicochemical properties of the chitin isolated from cicadae (Platypleura kaempferi) periostracum was investigated. The prepared chitin was white flake form and the yield was 31.7%. The chitin was degraded into oligosaccharide during acid hydrolysis at 30℃ with concentrated HCl. The hydrolysis rate was 6.8% only after 0.5 h reaction, but increased to 44.0% after 24 h reaction. In distribution of the oligosaccharides in the hydrolyzates, ratio of GlcNAc1-3 content increased from 66.5% after 0.5 h reaction to 84.4% after 12 h reaction. The ratio of monomer GlcNAc content was 79.4% after 24 h reaction and no oligosaccharides bigger than GlcNAc4 was detected. It is found that cicadae periostracum chitin belongs to α-chitin resulting from the FT-IR spectra similar with those of crab and shrimp chitins. In X-ray diffractometer, two peaks were exhibited at 2θ = 9.5˚ (interplanar distance: 9.36Å) and 2θ = 19.4o(4.58Å). The crystallinity index and crystal size of the chitin were determined to be 81.9% and 4.6 nm, respectively, which are similar with those of crab and shrimp chitins, again confirming that cicadae periostracum chitin belongs to α-chitin. The degree of acetylation of cicadae periostracum chitin was calculated to be 88.1%.

조혈전구세포의 시험관 증식 및 분화에 대한 HoxB4와 STAT3의 상호조절 연구

홍성현 ( Sung Hyun Hong ),양승집 ( Seung Jip Yang ),김진아 ( Jin A Kim ),오일환 ( Il Hoan Oh ) 한국조직공학·재생의학회 2007 조직공학과 재생의학 Vol.4 No.2

Self-renewal of hematopoietic stem cells(HSC) is a major mechanism for regeneration of blood tissues from HSCs. Previous studies have identified HoxB4 and STAT3 as an important molecular mechanisms regulating HSC self-renewal, but potential interaction of the two remains unknown. To address the issue, transgenic mice for constitutively activated STAT3(STAT3-C) was examined for HoxB4 expression, but no difference in the HoxB4 expression level was seen compared to the control mice. On the contrary, when HoxB4 was co-transduced with dominant negative(dnSTAT3), the enhancing effect of HoxB4 on the proliferation of 5-FU stimulated bone marrow cells were significantly decreased as compared to the HoxB4 alone group. Similarly, the effect of HoxB4 on the maintenance of undifferentiated state as determined by lineage marker was significantly deteriorated by co-expression of dnSTAT3. Taken together, these results suggest that STAT3 activity could be a down-stream of HoxB4, being required for HoxB4-mediated enhancing effects on in vitro cultured hematopoietic precursor cells.