회원작품 - 마실

김대희,Kim, Daehee 대한건축사협회 2018 建築士 Vol.592 No.-

연소중 미분탄의 발광 분석 및 입자 채집 관찰

김대희(Daehee Kim),최상민(Sangmin Choi) 한국연소학회 2010 한국연소학회지 Vol.15 No.2

Combustion behavior of pulverized coal particles in a post-combustion gas reactor was investigated. Radiation emission from coal particles were analyzed by direct photograph and CH<SUP>*</SUP> radical chemiluminescence intensity. Coal particles were sampled during the combustion and were observed by scanning electron microscopy (SEM) and cross section micrograpy technique. Two coal types(one bituminous and one subbituminous coals typically used in the Korean power plants) were tested at typical combustion environment. Gas flow conditions were controlled to represent temperature and oxygen concentration. Experimental data were discussed along with conceptual descriptions of pulverized coal combustion, where particle heat-up, release and combustion of volatiles, and char combustion were sequentially progressed.

Combustion Characteristics of Hydrogen-Enriched Propane in a Dump Combustor with a Bluff-Body

Daehee Kim(김대희),Junggoo Hong(홍정구),Hyundong Shin(신현동),Sangmin Choi(최상민) 한국연소학회 2009 KOSCOSYMPOSIUM논문집 Vol.- No.38

Combustion characteristics of a partially premixed flame in a dump combustor were studied to determine the effects of hydrogen enrichment in propane. A bluff-body was used for flame stabilization. Fuel mixtures of hydrogen mole fraction ranging from 0.1 to 0.5 were burnt at ambient pressure within a quartz chamber. Tests were carried out keeping the total reactants flow rate by adjusting the fuel and air flow rates. Fluctuations of pressure were measured by a piezoelectric pressure sensor. Instantaneous flame structure and OH chemiluminescence images were caprured by a High-speed Intensified Charged Coupled Device (HICCD) camera and Intensified Charged Coupled Device (ICCD) camera. It is shown that hydrogen enrichment in propane induces increase of the frequency and amplitude of pressure fluctuations. Flame existence region seems to be very alike, but instantaneous flame behavior for one cycle showed a different moving tendency according to hydrogen enrichment. Also, location of primary reaction zone was changed from the inner recirculation zone to the turbulent shear layer. The reason is that hydrogen-enriched flame has more fast chemical reaction rate compared to the propane flame so chemical aspects take precedence over flow aspects in the hydrogen-enriched flame.

미분탄 촤의 고온 총괄 CO₂ 가스화 반응율 분석을 위한 실험적 연구

김대희(Daehee Kim),최상민(Sanmin Choi),Christopher R. Shaddix,Manfred Geier 한국연소학회 2011 KOSCOSYMPOSIUM논문집 Vol.- No.43

During oxy-fuel combustion, pulverized coal combustion occurs in the presence of elevated CO₂ level because of flue gas recirculation (FGR). Recent experimental and computational investigations about oxy-coal combustion have suggested that char-CO₂ gasification rates are sufficiently high under oxy-fuel combustion conditions to significantly influence the char combustion process. However, experimental measurements of such rates and its kinetic data under the relevant high temperature conditions (T > 1700 K, 1 atm) are lacking and this makes it difficult to predict the effect of CO₂ gasification reaction on the overall char consumption rate. To address this, we have measured both the char particle temperature size and velocity statistics and the char mass loss when two U.S. coal chars(a bittuminous and a subbituminous) are introduced into a high-temperature optical flow reactor with nearly 100% CO₂. The experimental measurements show a temperature decrease from the gasifying particles (consistent with the strong endothermicity of the char gasification reaction) and show increasing mass loss with increasing residence time and temperature, as expected. The overall gasification rate and rate coefficient are derived from the measured data and compared with the literature data.

한국영화의 해외시장 진출을 위한 콘텐츠 전략 연구

김대희(Kim, Daehee),김미현(Kim, Meehyun) 한국영화학회 2014 영화연구 Vol.0 No.61

With taking into consideration of the universality of film contents, this study examines the concept of cultural codes as an element of ‘difference’, and how it participated in the success of Korean films. For this purpose, Hofstede 6-Dimension theory was applied to the reports of Korea’s Top 50 domestic box office, Korea’s Top 50 foreign box office, and international Top 50 worldwide box office from 1999 to 2012. The research concludes that Korean films that saw success overseas were more prone to recognizing individualism and indulgence compared to Korean films with domestic successes. In comparison, Korean blockbusters were relying on historical background and social context that is locality and were hard to be agreed by international audiences. In terms of films that were introduced into the East Asian market, melodramas saw much popularity, which focuses on relationships and communication that aligns with feminine sensibility. It implies that in Europe and North America, task-oriented characters with individualism would be more successful, while the East Asian markets are more attracted to dramas and relationships between characters.

비등방형 확산과 계층적 클러스터링을 이용한 칼라 영상분할

김대희(Daehee Kim),안충현(Chung-Hyun Ahn),호요성(Yo-Sung Ho) 대한전자공학회 2003 대한전자공학회 학술대회 Vol.2003 No.11

국제환경법상 환경정보공유에 관한 연구

김대희(Daehee Kim) 국제법평론회 2013 국제법평론 Vol.0 No.37

International Society has experienced a transition from co-existence era to cooperation era. With the change, International law has developed from law of co-existence to law of cooperation. The United Nations and the Charter in the political and diplomatic area or WTO and its agreements demonstrate the transitional trend. which is common in the whole area of international law and is based on information cooperation. However, international organization or international agreement for information cooperation have been not established in international environmental area. Awareness and solution to environmental problems require information cooperation. This study explores the existing international environmental law for sharing environmental information. ‘International Environmental Information Sharing’ means providing and receiving environmental information through notification, exchange, report and the response to a certain request for preventing environmental pollution or harm. It is a method to cooperate in international environmental law based on theoretical ground of goodneighborness and good faith. States constitute a single community of interests sharing natural resources such as air, sea and river. PCIJ and ICJ confirmed the idea of community of interest as general international law. Thus, states have to contemplate the community interest using shared natural resources. States have argued the Absolute Territorial Sovereignty or the Absolute Territorial Integration. We should consider the fact that They are not legal norms to be applied to environmental dispute settlement between parties, but only means to negotiate for their individual environmental interest. States have accepted the Limited Territorial Sovereignty when they experienced conflicts or disputes of environmental interest. Simply put, the duty to cooperate in international environmental law has been recognized as international customary law or developed as the soft law for sharing environmental information. It is Notification that the cardinal duty to share environmental information in the international environmental law is. Notification falls into two categories. One is prior notification, which is considered at the ‘planning stage’ of the particular industrial or economic activities and the other is notification of an emergency, which is considered in the operation of the activity. Notification accompanies the environmental impact assessment and the consultation. States shall discharge their due diligence to recognize or assess risk of their activity. If a state of origin is aware of risk of its activity in planning process or operation, the state is required to consult with the relevant states. Also, states, which are affected or likely to be affected by industrial activities of other state, enjoy the right to request the relevant environmental information to the state of origin with reasonable grounds. Some issues of notification in the international environmental law are as follows. A number of scholars say that procedural obligation such as the environmental impact assessment, notification and consultation has no binding effect in the planned stage of activities involving risk of transboundary harm. Certainly, Environmental Impact Assess is recognized as a part of international environmental law witnessed in ICJ’s Pulp Mills case and ITLOS’s advisory opinion on Responsibility and Obligation of States Sponsoring Persons and Entities with Respect to Activities in the Area. But, there is controversy over binding effect of notification and consultation of the planned activities' risk. International Environmental Information Sharing is to prevent transnational environmental harm. Responsibility to prevent the harm is materialized through the environmental impact assessment, notification and consultation. Default of the three procedural obligations or measures constitutes a breach of international obligation, that is, responsibility to preven

Multiple DiffServ 환경에서 종단간 QoS를 지원하는 Marking

김대희(DaeHee Kim),박우진(Woojin Park),정영환(Younghwan Jung),김경혜(Kyunghye Kim),안순신(Sunshin Ahn) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.1A

본 논문은 다수의 DiffServ(Differentiated Service) 도메인을 지나가는 Assured Forwarding(AF) 서비스 클래스의 종단간 QoS(Quality of Service)를 향상시키는 새로운 Marking Mechanism을 제안한다. 기본적인 개념은 패킷들이 최초 DiffServ 도메인으로 들어갈 때 부여받은 Marking 정보를 종단까지 유지하고, 이 정보를 근간으로 Marking을 수행하여 종단간 QoS를 보장받도록 해주는 것이다.

OpenCL을 활용한 이기종 파이프라인 컴퓨팅 기반 Spark 프레임워크

김대희(Daehee Kim),박능수(Neungsoo Park) 대한전기학회 2018 전기학회논문지 Vol.67 No.2

Apache Spark is one of the high performance in-memory computing frameworks for big-data processing. Recently, to improve the performance, general-purpose computing on graphics processing unit(GPGPU) is adapted to Apache Spark framework. Previous Spark-GPGPU frameworks focus on overcoming the difficulty of an implementation resulting from the difference between the computation environment of GPGPU and Spark framework. In this paper, we propose a Spark framework based on a heterogenous pipeline computing with OpenCL to further improve the performance. The proposed framework overlaps the Java-to-Native memory copies of CPU with CPU-GPU communications(DMA) and GPU kernel computations to hide the CPU idle time. Also, CPU-GPU communication buffers are implemented with switching dual buffers, which reduce the mapped memory region resulting in decreasing memory mapping overhead. Experimental results showed that the proposed Spark framework based on a heterogenous pipeline computing with OpenCL had up to 2.13 times faster than the previous Spark framework using OpenCL.

상용 CFD 코드에서 사용되는 촤 반응속도 모델에 대한 이해

김대희(Daehee Kim),최상민(Sangmin Choi) 한국연소학회 2013 KOSCOSYMPOSIUM논문집 Vol.- No.46

Commercial computational fluid dynamics (CFD) codes traditionally rely on the computational efficiency of the simplified single-film apparent char kinetic model to predict char particle temperatures and char conversion rates in pulverized coal boilers. The aim of this study is to evaluate the reliability of the single-film apparent kinetic model and to suggest the importance of proper use of this model. For this, a parametric study was conducted with a consideration of main parameters such as Stefan flow, product species, particle evolution, and kinetic parameters.