• 천문학회보
• /
• 제35권1호
• /
• pp.87.1-87.1
• /
• 2010

Main-belt comets (hereafter MBCs) are one of the hottest topics in the solar system astronomy. They are objects orbiting in the main asteroid belt which show cometary activity. Unlike most comets, which spend most of their orbit beyond 5AU from the Sun, MBCs follow near-circular orbits within the asteroid belt that are indistinguishable from the orbits of major population of the asteroids. P/2010 A2, the fifth MBC, was discovered by on January 6, 2010 by Lincoln Near-Earth Asteroid Research. It passed its perihelion at 2.01AU on December 3, 2009, about a month before it was discovered. With an aphelion of only 2.6 AU, P/2010 A2 spends all of its time inside of the frostline ~2.7 AU. We made observations of P/2010 A2 with Nishi-Harima Astronomical Observatory 2-m telescope only a week after the discovery. From the observed images, we found that the dust cloud was composed of large particles (>1mm) impulsively ejected between March and June, 2009. No coma was detected by our observations, suggesting that this object was no longer active. Consequently, we conjecture that these dust particles could be released by the impact collision among asteroids.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권3호
• /
• pp.971-989
• /
• 2015

With the development of cloud computing, more and more Web services are deployed on geo-distributed datacenters and are offered to cloud users all over the world. Through service composition technologies, these independent fine-grain services can be integrated to value-added coarse-grain services. During the composition, a number of Web services may provide the same function but differ in performance. In addition, the distribution of cloud datacenters presents a geographically dispersive manner, which elevates the impact of the network on the QoS of composite services. So it is important to select an optimal composition path in terms of QoS when many functionally equivalent services are available. To achieve this objective, we first present a graph model that takes both QoS of Web services and QoS of network into consideration. Then, a novel approach aiming at selecting the optimal composition path that fulfills the user's end-to-end QoS requirements is provided. We evaluate our approach through simulation and compare our method with existing solutions. Results show that our approach significantly outperforms existing solutions in terms of optimality and scalability.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.387-392
• /
• 1998

To establish a monthly data collection planning for the Ocean Scanning Multispectral Imager (OSMI), we have examined the global patterns of three impacting factors: pigment concentration, cloud cover, and sun glint. Other than satellite mission constraints (e.g., duty cycle), these three factors are considered critical for the OSMI data collection. The Nimbus-7 Coastal Zone Color Scanner (CZCS) monthly mean products and the International Satellite Cloud Climatology Project (ISCCP) monthly mean products (C2) were used for the analysis of pigment concentration and cloud cover distributions, respectively. And the monthly simulated patterns of sun glint were produced by performing the OSMI orbit prediction and the calculation of sun glint radiances at the top-of-atmosphere (TOA). Using monthly statistics (mean and/or standard deviation) of each factor in the above for a given 10$^{\circ}$ latitude by 10$^{\circ}$ longitude grid, we generated the priority map for each month. The priority maps of three factors for each month were subsequently superimposed to visualize the impact of three factors in all. The initial results illustrated that a large part of oceans in the summer hemisphere was classified into the low priority regions because of seasonal changes of clouds and sun illumination. Sensitivity tests were performed to see how cloud cover and sun glint affect the priority determined by pigment concentration distributions, and consequently to minimize their seasonal effects upon the data collection planning.

• 한국통신학회논문지
• /
• 제38B권7호
• /
• pp.512-518
• /
• 2013

분산 클라우드 컴퓨팅에서 자원 할당 알고리즘은 사용자 만족도와 서비스 수용 및 처리 능력과 밀접한 관련을 가지기 때문에 중요하다. 즉, 분산 클라우드에서는 서비스 처리를 위해 이용가능한 자원이 없을 때 발생하는 서비스 거부는 사용자 만족도를 반감시킨다. 따라서 본 논문에서는 서비스 거부를 최소화하기 위하여 데이터센터 자원 상황을 고려한 자원 할당 알고리즘을 제안한다. 제안하는 알고리즘은 Q-Learning 기반의 자원 할당량 학습에 의해서 클라우드 데이터센터에서 최대 자원 할당량 만큼 할당을 할 수 있으면 자원 할당량이 증가하고 그렇지 못할 때는 자원 할당량이 감소하게 된다. 본 논문에서는 제안하는 알고리즘과 기존의 두 알고리즘을 평가하고 제안하는 알고리즘이 두 알고리즘 보다 낮은 서비스 거부율을 보임을 증명한다.

• 한국정보시스템학회지:정보시스템연구
• /
• 제32권2호
• /
• pp.153-176
• /
• 2023

Purpose As non-face-to-face work environments become common due to COVID-19, interest in online collaboration tools that can communicate smoothly without time and space limitations is continuously increasing. Most of the prior studies are about the introduction, use intention, and satisfaction of cloud computing-based collaboration tools, and studies on the effects of collaboration tools on work-life balance and quality of life are somewhat lacking. Therefore, in this study, the characteristics of cloud computing-based collaboration tools were derived, and the effect on job satisfaction during work and job stress outside of working hours was confirmed. Design/methodology/approach This study applied the S-O-R framework and conducted an online survey of office workers who used cloud computing-based collaboration tools for more than three months. Hypotheses were tested using structural equations. Findings As a result of the analysis, among the characteristics of collaboration tools, stability, usefulness, and interoperability had higher job satisfaction as more stimuli were applied. In addition, the higher the job satisfaction during work, the higher the job performance, work-life balance, and quality of life.

• 천문학회보
• /
• 제32권2호
• /
• pp.76.1-76.1
• /
• 2007

• 방송공학회논문지
• /
• 제19권1호
• /
• pp.3-13
• /
• 2014

본 논문은 매우 빠른 속도로 개발 및 보급되고 있는 개인형 클라우드 서비스의 이용에 관한 탐색적 연구이다. 특히, 이용자 특성과 이용 행태에 주목하여, 플랫폼 및 콘텐츠 연계이용이 클라우드 서비스 이용에 미치는 영향을 실증적으로 검증하였다. 연구결과, 첫째 클라우드 서비스 이용은 사진, 음악, 음원과 같은 데이터 용량이 작은 콘텐츠를 중심으로 주로 연계이용되었다. 둘째, 클라우드 서비스 이용에 있어 '플랫폼 연계이용'이 제일 영향력 있는 요인으로 밝혀졌으며, SNS 이용, 이메일 이용, 개인의 혁신성 등도 통계적으로 유의미하게 나타났다. 본 연구는 개인형 클라우드 서비스에 대한 이론적 분석에 있어 선도적인 연구로서, 클라우드 서비스의 개발 및 관련 산업 진흥 정책의 수립에 있어 이용자 특성과 이용 행태의 고려가 필요하다는 함의를 제공하고 있다.

• 서비스연구
• /
• 제10권4호
• /
• pp.57-70
• /
• 2020

전 세계적으로 클라우드 서비스는 다양한 산업과의 융합을 통하여 산업의 생산성을 향상시키고 혁신을 가속화하는 핵심 인프라로써 지속적인 시장규모의 확대와 전 산업으로의 확산이 전망되고 있다. 특히 COVID-19로 인한 글로벌 팬데믹 현상으로 인해 클라우드 서비스는 언택트 시대를 대응하기 위한 핵심 인프라로 인식하는 계기가 되었다. 그러나 아직 국내에서는 시장 확대를 위한 전 단계에 머물러 있는 것이 현실이다. 본 논문은 확장된 TAM을 통하여 각 산업별로 클라우드 서비스가 어떠한 경로로 사용자에게 수용될 수 있으며 어떠한 요인들이 클라우드 서비스를 사용자에게 수용과 회피의 영향을 미치는지를 실증 분석하고자 한다. 이를 위하여 클라우드 서비스 이용의도를 분석하기 위한 산업분야를 선정하고, 제안한 확장된 기술수용모델을 통하여 가설검정을 통해 각 산업별 클라우드 서비스 수용의도에 미치는 영향과 요인을 분석하였다. 산업분야는 교육, 금융, 제조, 의료의 4개의 산업분야를 선정하였고 TAM의 매개변수와 클라우드의 핵심특징과 기타 요인을 종합적으로 검토하여 요인을 도출하였다. 실증 분석을 수행한 결과 4개 산업분야별로 클라우드 서비스 수용의도에 영향을 미치는 요인들에 차이점이 나타났는데, 이는 산업별로 클라우드 서비스의 도입이나 이용에 대한 인식의 차이가 있음을 의미한다. 궁극적으로 본 연구를 통하여 산업별로 클라우드 서비스 이용의도를 파악하는데 도움을 줄 수 있을 뿐만 아니라 클라우드 서비스 제공자들이 각 산업에 클라우드 서비스를 확대하여 제공하는데 도움을 줄 수 있을 것으로 기대한다.

• 한국환경과학회지
• /
• 제28권9호
• /
• pp.765-784
• /
• 2019

The synoptic structural characteristics associated with heavy snowfall (Bukgangneung: 31.3 cm) that occurred in the Yeongdong area on 20 January 2017 was investigated using surface and upper-level weather charts, European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data, radiosonde data, and Moderate Resolution Imaging Spectroradiometer (MODIS) cloud product. The cold dome and warm trough of approximately 500 hPa appeared with tropopause folding. As a result, cold and dry air penetrated into the middle and upper levels. At this time, the enhanced cyclonic potential vorticity caused strong baroclinicity, resulting in the sudden development of low pressure at the surface. Under the synoptic structure, localized heavy snowfall occurred in the Yeongdong area within a short time. These results can be confirmed from the vertical analysis of radiosonde data and the characteristics of the MODIS cloud product.

• 품질경영학회지
• /
• 제50권4호
• /
• pp.843-861
• /
• 2022

Purpose: This study explores the impact of digital transformation (DT) strategies on gaining a competitive advantage in interactive educational services. Methods: We develop a service value proposition model by analyzing educational service elements to confirm the impact of DT in the classroom through case studies. This study focuses on educational services that DT has a positive impact on organizational competitiveness by providing opportunities for customers to engage in operational processes. This case study summarizes competitiveness using SWOT (strengths, weaknesses, opportunities, and threats) analysis. Results: The findings of the case study indicate that DT-enabled competitive factors contribute to an organization's competitive advantage. The study results present key resource as social cloud services, data combination, content sharing, and products/services. The online application that collects user data about education and shares class and evaluation information creates a new class operational process in the field of educational service for a value proposition of collection-merging-sharing with social cloud function. Conclusion: The results of this study can be used as a good guideline for educational service providers interested in applying DT for improved customer satisfaction and educational organizations' competitiveness. In addition, the study findings provide theoretical and practical implications on SWOT approaches to changing the educational service provision ways through digital transformation.