• Information and Communications Magazine
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• v.30 no.9
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• pp.40-48
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• 2013

본고에서는 ITU-T SG13에서 진행중인 N-스크린 서비스 표준화에 대하여 알아본다. N-스크린은 연결성, 이동성, 통합성의 세가지 특성을 갖는 미디어 이용과 콘텐츠 소비환경을 말한다. N-스크린 서비스는 OSMU (One Source Multi Use), Handover, Collaboration의 세가지로 분류될 수 있다. OSMU는 동일한 콘텐츠를 여러 기기에서 이용하는 서비스 형태이며, Handover는 한 단말에서 보던 콘텐츠를 다른 단말로 이어보는 서비스 형태이고, Collaboration은 서로 다른 단말상에서 서로 다른 콘텐츠가 유기적인 관련성을 가지고 서비스를 제공하는 형태이다.

• Journal of Animal Environmental Science
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• v.18 no.1
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• pp.9-18
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• 2012

The output of Korea's livestock industry represents about 40% of the total agricultural production, making it the most high value-added sector in the entire agricultural and forestry industry. However, the fatal epidemics such as foot-and-mouth disease and avian influenza spurs demands for the advanced management of livestock production with IT technologies. U-Livestock means the application of ubiquitous technologies to livestock production. In this study, U-Livestock service models are established on the basis of the life cycle of livestock by using local and overseas cases. The objectives, contents, and structures of service models are required to be designed in detail respectively. The integration of such service models is expected to he1p modernize the livestock industry and raise the productivity of sector.

• 한국IT서비스학회:학술대회논문집
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• 2008.11a
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• pp.26-34
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• 2008

정보통신기술의 발전과 그에 따른 사회경제적 수요 변화에 따라 기존 인터넷 기반의 전자정부가 접근성(accessibility), 활용성(availability) 및 개인화(personalization) 제고차원에서 무선 기반의 전자정부(Mobile-Government), TV 기반의 전자정부(TV-Government), Ubiquitous-Government, (이하 U-Gov) 등으로 빠르게 전환되고 있다. 이와 같은 전자정부서비스의 전환점에서 본 연구는 TV기반 전자정부 서비스 제공 전략에 대한 시론적 연구이다. 따라서 본 연구에서 T-거버먼트의 기술적.사회적 환경변화와 미국, 영국 등 해외 사례와 우리나라의 T-거버먼트 서비스 제공 현황을 분석하였다. 그리고 이러한 거시적 기술적 환경분석과 국내외 사례분석을 토래로 향후 T-거버먼트 개발시 고려사항과 추진전략을 제시하였다.

• Information and Communications Magazine
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• v.30 no.8
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• pp.11-19
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• 2013

본고에서는 M2M/IoT 통신의 실현을 위한 무선 통신망 기술을 알아보고 IoT 통신을 위한 요구사항과 이를 해결하기 위한 연구 동향을 살펴본다. 특히, 많은 수의 IoT 디바이스가 싱크 노드를 이용하여 IP 망에 접속하는 Wireless Sensor network(WSN)에서의 문제와, LTE-A와 같은 cellular 망을 이용하여 접속하는 IoT 서비스로 나누어 논의한다. WSN관점에서는 에너지에 대한 제약이 심한 환경을 고려하여 발생할 수 문제점들을 분류하고 이에 대한 다양한 해결책을 제시하며, Cellular 망에서는 현재의 LTE-A 망에 많은 수의 IoT 디바이스가 연결될 경우 발생할 수 있는 문제점들을 논하고 기존의 통신에 영향을 최소화 하며 IoT 서비스를 공존할 수 있는 연구 동향을 논한다.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.4
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• pp.369-376
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• 1996

Major atmospheric stability classification methods were evaluated with meteorological data obtained by scoustic sounding profiler (SODAR/RASS) in Seoul. The Psequill classificatio method, the method most widely used because of its good agreement in respect of synoptic scope under the steady state, fails to describe the time lag, the response time on stability by heating or cooling caused by daily insolation or noctrunal surface radiation. Horizontal and vertical standard deviation of wind fluctuation $(\sigma_A and \sigma_E)$ method tend to classify night-time stable condition (E, F class) into unstable condition (A, B class). The classification matrix tables for Vogt's vertical temperature difference and wind speed using method ($\Delta$T $\cdot$ U) and bulk Richardson number (Rb) were amended for practical use over Seoul. The modified tables for $\Delta$T $\cdot$ U and Rb method were made by using comprehensive frequency distribution from Pasquill's method and other existing results, and the correlation coefficient(r) was equal to 0.829. It was confirmed that atmospheric stability could be changed with monitoring site characteristics, height and vertical difference between sensors of monitoring station, and classification method itself.

• Journal of Korea Planning Association
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• v.53 no.6
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• pp.87-99
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• 2018

The purpose of this study is to analyze the impact of municipal sustainability policy efforts on citywide $CO_2$ emissions. 25 cities in the U.S.A., which offer data on $CO_2$ emissions and are included in the top 50 largest cities in the U.S.A. according to its estimated population, were selected as study cities. This study utilizes the Sustainable Cities Seriously Index of Portney and selects data for the index at the city level. For analysis, this study employs correlation analysis, and OLS regression analysis. The results show that each city has around 30 sustainability policies and emits $12.76tCO_2$ per year on average. In addition, when the number of sustainability policies increases by one, the amount of $CO_2$ per capita decreases by $0.7tCO_2$. This means that the more cities employ sustainability policies, the less $CO_2$ those cities emit. The results of this study support the idea that active efforts on behalf of municipal governments toward the development of sustainability policies are needed to handle citywide $CO_2$ emissions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.231-237
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• 2020

In this paper, we implemented a home IoT system based on MQTT protocol. In this system, data are collected from sensors in real time and transmitted to the server system. Based on collected data, home devices could be controlled automatically or manually. By using the MQTT protocol, we were able to see the data values of sensors collected in real time according to the topic setting. We implemented a system that automatically sets up home devices based on topic data, and it worked. The system is expected to be useful in applications that require monitoring and tracking of data in real time.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.795-810
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• 1998

현재, 컴퓨터를 사용하는 실시간 시스템의 응용분야에 대한 요구가 급속히 증가하고 있다. 그러나 이러한 실시간 시스템의 개발은 체계적인 접근방법이 부족하다는 이유로 더디게 진행되고 있다. 체계적인 접근방법의 하나는 실시간 시스템의 시간적인 특성과 기능적인 행동을 잘 추상화 해 줄 수 있는 좋은 모델을 사용하는 것이다. 지금까지 객체지향 개념에 기반한 많은 모델들이 개발되어 소개되고 있다. 그 중 UCI에서 개발된 TMO (Time-triggered Message-triggered Object) 모델은 위에서 언급한 요구사항을 잘 만족시켜 준다. [1]본 논문에서는 이러한 TMO 모델을 가장 잘 명세해 줄 수 있도록 해 주는 TMO 모델 명세언어인 C++T를 설계하고 이에 대해 상세히 기술한다. 또한, 이러한 C++T 명세를 기존의 언어인 C++로 번역해 줄 수 있는 C++T번역기를 설계하고 개발한다. 마지막으로, TMO 명세언어 C++T를 기반으로 한 TMO 통합개발환경에 대하여 소개한다.

• Journal of Internet of Things and Convergence
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• v.6 no.2
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• pp.25-29
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• 2020

The elliptic curve crypto-algorithm is widely used in authentication for IoT environment, since it has small key size and low communication overhead compare to the RSA public key algorithm. If the scalar multiplication, a core operation of the elliptic curve crypto-algorithm, is not implemented securely, attackers can find the secret key to use simple power analysis or differential power analysis. In this paper, an elliptic curve scalar multiplication algorithm using a randomized scalar and an elliptic curve point blinding is suggested. It is resistant to power analysis but does not significantly reduce efficiency. Given a random r and an elliptic curve random point R, the elliptic scalar multiplication kP = u(P+R)-vR is calculated by using the regular variant Shamir's double ladder algorithm, where l+20-bit u≡rn+k(modn) and v≡rn-k(modn) using 2^lP=∓cP for the case of the order n=2^l±c.

• Journal of the Korean Society of Marine Environment & Safety
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• v.7 no.2
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• pp.13-22
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• 2001

We studied the characteristics of marine casualties within the area under control of Korea National Maritime Police and leeway of drifting vessel. According to 5 years＇(1995~1999) data of casualties, it was found that the occurrence of casualties by fishing boats ranked the highest and a considerable numbers of casualties took place more than 20 miles off the shore. From a result of field experiment of G/T 50 tons vessel off Busan harbor on Apr. 26~28, 2000, we computed that the linear equation of leeway speed(cm/s) was 1.01$\times$U(U : wind speed in m/s)+11.36 with correlation coefficient between wind speed and leeway speed being 0.252 and we found leeway angle range from $+87^{\circ}$(right) to $-78^{\circ}$(left ) of the downwind direction.