• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.535-537
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• 2002

SMIL(Synchronized Multimedia Integration Language)은 웹에서 멀티미디어를 동기화하여 표면하기 위하여 W3C에서 제안만 언어이다 이것은 인터넷 방송이나 능과 컨텐츠의 제작, 온라인 교육 등 다양한 분야에 이용될 수 있다. SMIL의 활성화를 위해서는 QoS를 보장할 수 있는 멀티미디어 서버와 저작도구의 개발과 함께 재생도구의 개발 또한 필수적으로 요구된다. 1998년에 발표된 SMIL 1.0에 비해서 2001년 8월 발표된 SMIL 2.0은 사용자와의 상호작용을 통하여 멀티미디어 컨텐츠를 프리젠테이션할 수 있는 기능이 강화되고 추가되었다. 따라서, 재생도구 개발 시에 사용자에 의한 각종 이벤트를 인식하여 동기적인 재생 시간을 결정하는 스케줄러의 개발이 필수적이다. 본 논문에서는 SMIL 2.0 문서를 재생하기 위하여 핵심적으로 필요만 이벤트 저리를 위만 실시간 스케줄러를 설계 및 개발하였다. 이것은 SMIL- 표준안에 정의된 여러 종류의 프로파일에서 재상용될 수 있고, XHTML+SMIL이나 SMIL Animation 과 같은 SMIL을 통합하는 다른 표준들에도 응용될 수 있을 것으로 기대된다.

• Journal of the Korea Society of Computer and Information
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• v.19 no.6
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• pp.1-10
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• 2014

In this paper, we propose a real-time video playback scheme for the N-Screen service based on Windows Azure. This scheme creates several playback blocks based on the performance of each node by non-uniform splitting of the original video. To reduce transcoding-time, it allocates the playback blocks to a corresponding node by transcoding the playback blocks. Through the simulation, we show that it is more effective to use real-time video playback for the N-screen service than the previous method. The proposed scheme splits an AVI format 300MB source video with non-uniform playback blocks. It allocates the playback blocks to the heterogeneous node of Windows Azure, the commercial cloud system and measures of transcoding-time by transcoding non-uniform playback blocks to mp4 and Flv format. As a result, the proposed scheme improves the performance of the N-screen service based on Windows Azure compared to the previous uniform split strategy.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2115-2123
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• 2000

This research was designed to investigate the mathematical model and kinetics of phenol desorption from spent activated carbon. elucidating the desorption characteristics of phenol in the case of using acetone. The Freundlich isotherm constant ($k_e$) is expressed as a function of temperature: $k_e(T)=0.1exp(797.297/T)$. The Freundlich isotherm constant(n) is a weak temperature function and is rarely affected by temperature below $50^{\circ}C$. whereas it is necessary to correct the n value with respect to temperature above $100^{\circ}C$ owing to significant deviation (~5%). Based on the assumption that the surface desorption reaction of phenol is rate limiting, the desorption model was developed. Desorption reaction constant($k_d$) was determined by means of fitting the theoretical results best to experimental ones. The Arrhenius relationships for $k_d$ was expressed by: $k_d(sec^{-1})=0.0479{\cdot}exp(-3037/T)$. The model was verified by comparing the experimental ones under different reaction conditions with the theoretical results determined by the previously estimated $k_d$. Since the difference between them is with 5%, it is expected that the desorption model of this research seems to be appropriate to explain the desorption of phenol from activated carbon by acetone. According to studies of the model. regeneration time and ratio was estimated as a function of temperature under present conditions as follows: (1) regeneration time : ${\tau}_{reg}(hr)=-0.08130T_c+8.4775$. (2) regeneration ratio : ${\eta}(%)=0.2210T_c+83.745$. The regeneration time at 15, 55, and $100^{\circ}C$. respectively. was 7, 4.2, and 0.35 hours, whereas the regeneration ratio was 87. 96. and 99%. respectively. Also. studies of the model would make it possible to determine the regeneration time and ratio under other specific conditions (temperature, applied acetone volume, amount of activated carbon, and initially adsorbed phenol amount).

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.2
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• pp.31-37
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• 2001

Digital servo implementation in optical servo chip has been spotlighted since it is easy to integrate with other blocks and it has less sensitive characteristics change in terms of temperature variation and better flexibility to the system variation like pick-up. Therefore, Optical disc players adopted digital servo are increasing in market. However, one drawback of digital signal processor embedded digital servo is power consumption that is one of the most important factors of portable optical disc player system. For that reason, this paper introduces new architecture to reduce power consumption of digital servo by means of reducing DSP load but increasing minimum hardware size. The main idea of reducing power consumption of digital servo greatly is utilizing CDP characteristics as most operations are done and used up most operating steps of DSP at the initial time, but most power consumption is occurred in play mode. Therefore, if operating steps for digital filtering in play mode could be reduced greatly, power consumption of overall system can be reduced greatly. This paper shows an example that low power digital servo architecture whose current is reduced almost 83%, compare to that of digital servo which is not applied by the low power architecture introduced in this paper.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.432-437
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• 2005

An electric swing adsorption (ESA) process for recovering highly pure $CO_2$ from the mixed gases was tested. In this study, activated carbon fibers were used as an adsorbent. The activated carbon fibers showed fast adsorption rate and the high adsorption capacity for $CO_2$ adsorption under the condition of the ambient pressure. Activated carbon fiber with higher specific surface area was suitable to repeated adsorption-desorption cycle process, showing consistent breakthrough curve. Especially, the regeneration method by vacuum combined with ESA improved the performance of desorption process by an additional 17％ regeneration efficiency compared to a vacuum only method, and showed the high regeneration efficiency at comparatively low 7-8 Wh energy.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.2
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• pp.124-132
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• 2005

We propose a method using a transformation of an object and a scene tree in order to author MPEG-4 contents for mobile devices in this paper. The method transforms media objects in the scene into geometry objects in order to reduce initial loading time of the contents, and reduces an external form of each object in a scene of the content for presenting it efficiently on the small interface of mobile devices. Therefore, the contents for mobile devices are reconstructed by the method. An original object in the scene is presented on a mobile device when a user clicks a related geometry object. The method was applied to a conventional authoring tool, so we could find that the method showed an efficient presentation of MPEG-4 contents on mobile devices.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.111.2-111.2
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• 2011

최근 지구온난화로 인해 국제적으로 이산화탄소 저감에 대한 연구가 진행되고 있으며 특히, 이산화탄소의 분리 및 유용물질 전환 등의 다양한 방법에 대한 연구가 활발히 이루어지고 있다. 이산화탄소를 메탄으로 전환시키는 생물학적 반응은 acetotrophic methanogen, hydrogenotrophic methanogen 등의 미생물이 관여한다. 본 연구에서는 hydrogenotrohpic methanogen을 이용하여 메탄으로 전환하고자 하였다. 이를 위해 이산화탄소와 수소의 체류시간에 대한 연구를 진행하였으며, 선행 연구로 혐기성슬러지의 혼합배양균으로부터 hydrogenotrophic methanogen을 우점종화 하기 위해 고정층 반응기를 이용하여 이산화탄소와 수소 가스를 주입하여 고농도로 배양하였다. 그 결과, 반응기내의 이산화탄소의 메탄전환 균주로써 수소를 환원제로 이용하는 hydrogenotrophic methanogen이 배양되었음을 확인하였다. 이산화탄소와 수소가스의 체류시간에 따른 이산화탄소의 생물학적 메탄 전환 실험 결과, 약 4시간에서 이산화탄소의 저감률이 99%이었으며, 체류시간이 2시간, 1.5시간인 경우 이산화탄소의 저감률은 각각 71%, 68% 이었다.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.699-708
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• 2002

Since various terminals and different networks get involved in playing of a multimedia presentation, the case that the presentation QoS at a destination should be different from the QoS of multimedia data at a source occurs frequently. For playing the multimedia presentation, the multimedia data at a source should be transcoded into the multimedia data satisfying the QoS required at the terminal. The problem of generating the transcoding path is that, for a given multimedia presentation, different transcoding paths depending the terminal and networks should be generated. That is, a fixed transcoding path cannot be applied to a multimedia presentation. Instead, whenever the terminal and network to play the presentation get determined, a proper transcoding path should be regenerated automatically. In this paper, the algorithm for generating the transcoding path and the method for checking the playability of the generated path are proposed. The generating algorithm adopted the technique of Context Free Grammar in describing the set of transcoding resources and a user's transcoding rules in order to utilize the well-known compiler techniques. For the playability check, a method of computing the transcoding time and the delay time between data units are proposed. Finally all the proposed methods were implemented in the stream engine, called Transcore and the presentation-authoring tool, called VIP, we had developed. And the test results with a sample scenario were presented at the last.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.341-345
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• 2020

An in situ regeneration of activated carbon bed using an ozonated water was studied in order for avoiding the carbon loss, contaminant emission and time consuming for discharge-regeneration-repacking in a conventional thermal regeneration process. Using phenol and polyethylene glycol (PEG) as adsorbates, the adsorption breakthrough and in situ regeneration with the ozonated water were repeated. These organics were supposed to degrade by the oxidation reaction of ozone, regenerating the bed for reuse. As the number of regeneration increased, the adsorption capacity for phenol was reduced, but the change was stabilized showing no further reduction after reaching a certain degree of decrement. The reduction of adsorption capacity was due to the increase of pore size resulting in the decrease of specific surface area during ozonation. The adsorption capacity of phenol decreased after the ozonated regeneration because the in-pore adsorption was prevalent for small molecules like phenol. However, PEG did not show such decrease and the adsorption capacity was constantly maintained after several cycles of the ozonated regeneration probably because the external surface adsorption was the major mechanism for large molecules like PEG. Since the reduction in the pore size and specific surface area for small molecules were proportional to the duration of contact time with the ozonated water, careful considerations of the solute size to be removed and controlling the contact time were necessary to enhance the performance of the ozonated in situ regeneration of activated carbon bed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.61-64
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• 2009

본 논문에서는 단축과 2축 회전형추적시스템의 장점을 가진 시간 제어 극축회전형(Chronological Polar axis tracking) 태양광추적발전시스템에 대한 연구결과를 보여주고 있다. 천체 망원경의 별 추적 방식과 같은 시간 제어 극축 회전 방식으로 태양 추적방법의 정밀도를 높이면서 제어를 간소화하였고 계절 변화에 따른 태양 남중고도의 변화를 패널이 동시 추적 가능하도록 하였다. 향후 집광형태양광발전시스템에 적용가능성을 보였다.