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A New MDR-based RFID System Architecture for Ubiquitous Computing Environment
정동원,이이섭,Jeong Dongwon,Lee Lee-Sub 한국시뮬레이션학회 2005 한국시뮬레이션학회 논문지 Vol.14 No.4
유비쿼터스 컴퓨팅은 무수히 많은 센서들이 관련 데이터 처리 시스템들과 또는 센서들 간의 정보 공유를 통해 서비스를 제공하면서 특정한 장치나 위치에 구애받지 않고 사용자들이 서비스를 이용할 수 있도록 해 준다. 이 논문에서는 유비쿼터스 환경하에서 현재 가장 활발하게 활용되고 있는 RFID(Radio Frequency IDentification) 시스템이 지니는 문제점을 정의하고 이를 극복할 수 있는 새로운 RFID 시스템 구조를 제안한다. 현재의 RFID 시스템은 특정 분야에만 한정하여 단순히 미리 주어진 태그의 식별자를 통해 대상을 식별하는 응용만으로 그 활용성이 제한되어 있다. 이 논문에서는 이러한 제한된 현재의 RFID 시스템의 문제점을 해결하고 유비쿼터스 환경에 적합한 활용성을 극대화할 수 있는 MDR(Metadata registry) 기반의 RFID 시스템 구조를 제안한다. 제안된 시스템은 특정 응용 분야에 종속되지 않고 다양한 분야와의 원활한 연계성을 제공한다. 또한 새로운 정보의 의미를 동적으로 처리할 수 있기 때문에 보다 넓은 응용 범위를 제공한다.
온도 성층화를 갖는 예혼합압축자기착화엔진에서 Booster 효과에 관한 수치해석
정동원(Dongwon Jeong),권오석(Oseock Kwon),임옥택(Ocktaeck Lim),박규열(Kyuyeol Park) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4
The method of thermal stratification in cylinder is known for reducing rate of pressure rise, but which has its limit to extend the higher-load operating region of HCCI engines, giving an output of insufficient IMEP. High fueling rate could be one way to get the enough IMEP but it could be occurring engine knock. This work investigates the potential of in-cylinder thermal stratification for reducing the rate of pressure rise in DME HCCI engines, and the coupling between thermal stratification and booster effect to get reduced rate of pressure rise as well as high IMEP. The computations were conducted using Senkin application of the CHEMKINll kinetics rate code, and kinetic mechanism for Di-Methyl Ether (DME). DME has unique 2 stage reaction called Low Temperature Reaction (LTR) and High Temperature Reaction (HTR). Due to the heat release from LTR, the thermal stratification of in-cylinder would be formed just before HTR with large temperature difference so the heat release from oxidation reaction dispersed through combustion process. Intensity of intake pressure is closely concerned in input calorie which means a higher IMEP would be appeared without high fueling rate. The study also shows that increasing the in-cylinder thermal width of the charge between each zone would allow the booster pressure to be raised from 0.1㎫ to 0.18㎫ to get the higher IMEP as well as high thermal efficiency with low emissions.
분산화와 개방성 기반의 메타데이터 레지스트리 확장 모델
정동원(Dongwon Jeong) 한국정보기술학회 2020 한국정보기술학회논문지 Vol.18 No.1
This paper proposes an extended model for resolving the problems of the existing metadata registry model. ISO/IEC 11179—Metadata registries is an international standard that has been developed to improve data interoperability. The metadata registry model provides a centralized metadata management and closed metadata verification scheme, and thus the use of the model compromises extensibility and usability. This paper analyzes the limitations of the existing metadata registry management scheme and proposes an extended metadata registry model to address the limitations. The extended model proposed in this paper enables a decentralized management and open participation. This paper also shows a possible implementation model to realize the proposed model, and a comparative evaluation and the advantages of the proposed model are described.
실내공간 저농도 CO<sub>2</sub> 포집을 위한 알칼리 함침 정전나노섬유 연구
정동원 ( Dongwon Jeong ),김상범 ( Sangbum Kim ),조영민 ( Youngmin Jo ) 한국공업화학회 2018 공업화학전망 Vol.21 No.4
Carbon nanofibers were electrospun from melamine-blended polyacrylonitrile (MACNFs), for improved indoor level CO<sub>2</sub> removal of the fibrous adsorbent. The dopant (melamine) was used to provide free and basic nitrogen functionalities, as well as to shorten the fabrication time of the nanofibers. Upon final CO<sub>2</sub> activation of the nanofibers, the specific surface area and microporosity were enhanced. As per chemical properties, the surface basicity was improved through the significant tethering of pyridone. The sample, MACNF-7 (10 mL polymer solution doped with 0.7 g melamine) provides the optimum doping ratio to achieve the highest CO<sub>2</sub> adsorption capacity of 3.15 mmol/g. This performance was based on simultaneous and just-adequate improvement of the microporosity (physical) and surface basicity (chemical) of the adsorbent. However, the selective adsorption of CO<sub>2</sub>, in a binary mixture with nitrogen, showed the predominance of the improved chemical properties over microporosity; the highest CO<sub>2</sub> selective capture (1.22 mmol/g) was exhibited by applying CO<sub>2</sub> : N<sub>2</sub> of 0.15 : 0.85., with the selectivity fold of 58.19 at 273 K. In a 5-fold regeneration test, a stable and robust performance was achieved throughout the five cycles.
블록체인 기반 자격증 관리 시스템의 정성적 평가 요소에 대한 통계 데이터 기반 성능 분석
정동원(Dongwon Jeong),이석훈(Sukhoon Lee) 한국정보기술학회 2020 한국정보기술학회논문지 Vol.18 No.9
This paper shows the quantitative evaluation results on the qualitative evaluation items of the blockchain-based certificate management system. The existing study provides the quantitative evaluation in the aspect of prompt authenticity verification. However, the study does not illustrate a quantitative evaluation of security, convenience, and reliability. This paper, therefore, describes the qualitative analysis and evaluation results in the aspect of the qualitative evaluation items. To achieve that, this paper collects a set of statistical data through a survey and analyzes the collected data. Also, the hypotheses are verified using the analysis results. This study quantitatively showed the contributions (security, convenience, and reliability) of the existing system.
Multi-Zone 모델링을 통한 온도성층화와 농도성층화가 존재하는 DME HCCI 엔진의 운전영역 관한 수치해석연구
정동원(Dongwon Jeong),임옥택(Ockteack Lim) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
This work investigates the potential of in-cylinder thermal stratification and fuel stratification for extending the operating ranges in HCCI engines, and the coupling between thermal stratification and fuel stratification. Computational results are employed. The computations were conducted using both a custom multi-zone version and the standard single-zone version of the Senkin application of the CHEMKINII kinetics rate code, and kinetic mechanism for di-methyl ether (DME). This study shows that the potential of thermal stratification and fuels stratification for extending the high-load operating limit by a staged combustion event with reduced pressure-rise rates is very large. It was also found that those stratification offers good potential to extend low-load limit by a same mechanism in high-load. However, a combination of thermal stratification and fuel stratification is not more effective than above stratification techniques for extending the operating ranges showing similar results of fuel stratification. Sufficient condition for combustion (enough temperature for Φ) turns misfire in low-load limit to operate engines, which also leads to knock in high-load limit abruptly due to the too high temperature with high Φ. DME shows a potential for maximizing effect of stratification to lower pressure-rise rate due to the characteristics of low-temperature heat release.
정동원(Dongwon Jeong),이유정(Yujeong Lee),이석훈(Sukhoon Lee) 한국정보기술학회 2021 한국정보기술학회논문지 Vol.19 No.5
Various studies have been conducted to resolve the growing social interest in the trash issue. Especially, drones and image recognition technologies are being applied to identify the distribution of trash. Accurate image acquisition must be prioritized to accurately identify the distribution of trash. In existing studies, research has been conducted on the effect of the altitude of a drone on the garbage recognition rate. However, the speed of a drone is also a very important factor. Therefore, this paper analyzes the effect of the drone speed on the image recognition rate and also defines the relationship between altitude, speed, and image recognition rate. The experimental results showed different results from the hypothesis that the slower the drone speed, the more accurate images will be acquired. The recognition rate was generally high at 2m/s, but the recognition rate was better at different speeds depending on the altitude. The research results of this paper can be used as basic data for related studies.
GML 문서의 유효성 및 독립성을 고려한 지리공간 데이터 가시화 시스템 설계 및 구현
정동원(Dongwon Jeong),김장원(Jangwon Kim),안시훈(Si-hoon Ahn),정영식(Young-Sik Jeong) 한국IT서비스학회 2008 한국IT서비스학회지 Vol.7 No.1
This paper proposes a geospatial data visualization system supporting validation of GML documents. GIS systems manage and use both of spatial and non-spatial data. Currently, most GIS systems represent spatial data in GML (Geography Markup Language) developed by OGC. GML is a language for representation and sharing of spatial information, and until now many systems have been developed in GML. GML does not support expression of non-spatial data, i.e., relational information of spatial objects, and thus most systems extend GML to describe non-spatial information. However, it causes an issue that the systems only accepting standard GML documents cannot process the extended documents. In this paper, we propose a new GIS data visualization system to resolve the aforementioned issue. Our proposed system allows the representation of both types of data supporting independency of spatial data and non-spatial data. It enhances interoperability with other relevant systems. Therefore, we can develop a rich and high quality geospatial information services.