• Journal of Microbiology and Biotechnology
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• 제17권3호
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• pp.414-419
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• 2007

Botryococcus braunii is a green colonial fresh water microalga and it is recognized as one of the renewable resources for production of liquid hydrocarbons. CFTRI-Bb-l and CFTRI-Bb-2 have been reported for the first time and their performance with regard to growth and biochemical profile is presented here. The present study focused on effect of carbon dioxide $(CO_2)$ on biomass, hydrocarbon, carbohydrate production, fatty acid profile, and carotenoid content in various species of B. braunii (LB-572, SAG 30.81, MCRC-Bb, N-836, CFTRI-Bb-l, and CFTRI-Bb-2) at 0.5, 1.0, and 2.0% (v/v) levels using a two-tier flask. $CO_2$ at 2.0% (v/v) level enhanced growth of the organism, and a two-fold increase in biomass and carotenoid contents was observed in all the B. braunii strains studied compared with control culture (without $CO_2$ supplementation). At 1 % and 2% (v/v) $CO_2$ concentrations, palmitic acid and oleic acid levels increased by 2.5 to 3 folds in one of the strains of B. braunii (LB-572). Hydrocarbon content was found to be above 20% at 2% $CO_2$ level in the B. braunii LB-572, CFTRI-Bb-2, CFTRI-Bb-l, and N-836 strains, whereas it was less than 20% in the SAG 30.81 and MCRC-Bb strains compared with control culture. This culture methodology will provide information on $CO_2$ requirement for growth of algae and metabolite production. B. braunii spp. can be grown at the tested levels of $CO_2$ concentration without much influence on culture pH.

• 한국기후변화학회지
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• 제9권3호
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• pp.273-281
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• 2018

The purpose of this study is to consider the effectiveness of continuous $CO_2$ emission monitoring in waste incinerator. To prevent global warming, many countries are trying to reduce $CO_2$, the main greenhouse gas. Currently, Korea is implementing an emission trading scheme to reduce $CO_2$, and waste incinerators are included in this scheme as major $CO_2$ sources. However, when using waste incinerators, $CO_2$ is discharged during incineration of various types of wastes, therefore it is very difficult to calculate the amount of emissions according to IPCC guidelines. In addition, the estimation of $CO_2$ emissions by calculation is known to lack of accuracy comparing with actual emissions. Currently, Korea is operating CleanSYS, which enables continuous measurement of gases emitted into the atmosphere. Therefore, it is possible to estimate the $CO_2$ emissions of waste incineration facilities. The IPCC, which published $CO_2$ emission calculation guidelines, recognizes that direct measurement of emission is a more advanced method in cases of various $CO_2$ emission sources such as a waste incineration facility. Also, Korean emission trading scheme guidelines allow estimation of $CO_2$ emissions by continuous measurement at waste incineration facilities. Therefore, this study considers the effectiveness of a direct measurement method by comparing the results of CleanSYS with the calculation method suggested by the IPCC guidelines.

• 한국분무공학회지
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• 제25권4호
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• pp.178-187
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• 2020

The current emission regulations, US Tier-4 and EU Stage-V, are only able to satisfy the regulations when all currently mass-produced emission reduction technologies such as EGR, DOC, DPF, and SCR are applied. Therefore, in this study, for the application of the Urea-SCR system to non-road diesel engines, the database was established by measuring the NO, NO2 concentration and calculating the NO2/NOx ratio based on the catalyst temperature and exhaust mass flow rate. Also, based on the measured NO2/NOx ratio data, a mathematical model was proposed to predict the NO2/NOx ratio at SCR catalyst, and the suitability of the model was verified through steady-state and transient mode. As a result of comparing the NO2/NOx ratio measured at the DOC outlet under the steady-state condition to two model values separately, the R2 was 0.9811 for the 3D map model and 0.9303 for the mathematical model. And in the case of the NO2/NOx ratio measured at the DPF outlet, the R2 was 0.9797 for the 3D map model and 0.935 for the mathematical model. It was confirmed that the R2 with the model value of the 3D Map of the mathematical model in the transient mode is 0.957, which shows high reliability.

• 정보보호학회논문지
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• 제18권4호
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• pp.103-109
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• 2008

많은 인터넷응용에서 인증 및 메시지 무결성을 제공하기 위해 PKI(Public Key Infrastructure) 기반 서비스를 제공하고 있다. 그리고 몇몇 연구에서는 PKI 기반의 P2P 서비스를 제안하기도 하였다. 그러나 P2P 응용의 경우 P2P의 open, dynamic, heterogeneous, autonomous 한 특성상 PKI의 적용이 어려우며, 특히 국가간 상호운용성을 지원하지 못하는 것도 P2P에의 적용을 현실적으로 어렵게 만든다. 본 논문에서는 PKI를 사용하지 않으면서도 MITM 공격에 안전한 P2P 신뢰전송 메커니즘을 제안한다. 본 메커니즘에서 각 피어는 자신의 공개키/비밀키 쌍을 자체적으로 생성하고 분배한다. 이 경우 MITM(Man in the Middle Attack) 공격에 취약하다는 문제가 있으나, 제안한 메커니즘은 MITM 공격에 대한 안정성을 제공한다. 본 메커니즘은 P2P 기반의 파일공유, IPTV, 분산자원 공유 등 다양한 분야에 응용이 가능하다.

• 한국CDE학회논문집
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• 제17권2호
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• pp.123-131
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• 2012

The requirements for computational resources to perform the structural analysis are increasing rapidly. The size of the current analysis problems that are required from practical industry is typically large-scale with more than millions degrees of freedom (DOFs). These large-scale analysis problems result in the requirements of high-performance analysis codes as well as hardware systems such as supercomputer systems or cluster systems. In this paper, the pre- and post-processing system for supercomputing based large-scale structural analysis is presented. The proposed system has 3-tier architecture and three main components; geometry viewer, pre-/post-processor and supercomputing manager. To analyze large-scale problems, the ADVENTURE solid solver was adopted as a general-purpose finite element solver and the supercomputer named 'tachyon' was adopted as a parallel computational platform. The problem solving performance and scalability of this structural analysis system is demonstrated by illustrative examples with different sizes of degrees of freedom.

• 제어로봇시스템학회논문지
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• 제2권4호
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• pp.324-329
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• 1996

In this paper, we present a vision algorithm to extract the tire information markings on the sidewall of tires. Since the appearance of tire marks is the same as its background, a primary feature to distinguish tire marks from their background is the roughness. Generally, the roughness of tire marks is different from that of its bakground: the surface of tire marks is smoother than the backgrounds. Light incident on the tire surface is reflected differently according to the roughness. For smoother surfaces, the surface irradiance is much stronger than that of rough surfaces. Based on these phenomena and observation, we propose an optimal illumination condition based on Torrance-Sparrow reflection model. We also develop an efficient reflectance-ratio based operator to extract the boundary of tire marks. Even with a very simple masking operation, we were able to obtain remarkable boundary extraction results from real experiments using many tires. By explicitly using the surface reflection model to explain the intensity variation on the black tire surface, we demonstrate that a physics-based vision method is powerful and feasible in extracting surface markings on tires.

• Journal of information and communication convergence engineering
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• 제12권3호
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• pp.186-192
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• 2014

Monolithic three-dimensional integrated chips (3D ICs) are an emerging technology that offers an integration density that is some orders of magnitude higher than the conventional through-silicon-via (TSV)-based 3D ICs. This is due to a sequential integration process that enables extremely small monolithic inter-tier vias (MIVs). For a monolithic 3D memory, we first explore the static random-access memory (SRAM) design. Next, for digital logic, we explore several design styles. The first is transistor-level, which is a design style unique to monolithic 3D ICs that are enabled by the ultra-high-density of MIVs. We also explore gate-level and block-level design styles, which are available for TSV-based 3D ICs. For each of these design styles, we present techniques to obtain the graphic database system (GDS) layouts, and perform a signoff-quality performance and power analysis. We also discuss various challenges facing monolithic 3D ICs, such as achieving 50% footprint reduction over two-dimensional (2D) ICs, routing congestion, power delivery network design, and thermal issues. Finally, we present design techniques to overcome these challenges.

• 한국멀티미디어학회논문지
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• 제1권2호
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• pp.142-153
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• 1998

본 논문에서는 웹 시스템을 기반으로 객체-관계 DBMS 내에 저장된 정보를 제공하기 위한 새로운 연동 방안인 Java 메소드 기법을 제안한다. 제안한 연동 방법은 객체-관계 DBMS의 핵심이라고 할 수 있는 객체 개념과 객체에 연관된 사용자 정의 함수(메소드)를 추가할 수 있도록 기능을 확장하여 기존의 C 언어나 SQL언어뿐만 아니라, Java 언어를 사용하여 정의하도록 함으로써 데이터베이스의 객체를 검색 할때 연관된 Java 메소드를 함께 검색하여 클라이언트에서 검색된 객체와 함께 수행하도록 하는 시스템을 설계하고 구현하였따. 이를 위해 JDBC와 Java RMI를 이용한 3계층 클라이언트/서버 구조의 Java 메소드 운영 환경을 설계 및 구현하고, 이를 객체-관계 DBMS와 연동하여 구현함으로써 제안한 방법의 효용성을 검증하였다.

• 한국통신학회논문지
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• 제35권5B호
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• pp.741-752
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• 2010

The ability to seamlessly switch between the macro networks and femtocell networks is a key driver for femtocell network deployment. The handover procedures for the integrated femtocell/macrocell networks differ from the existing handovers. Some modifications of existing network and protocol architecture for the integration of femtocell networks with the existing macrocell networks are also essential. These modifications change the signal flow for handover procedures due to different 2-tier cell (macrocell and femtocell) environment. The handover between two networks should be performed with minimum signaling. A frequent and unnecessary handover is another problem for hierarchical femtocell/macrocell network environment that must be minimized. This work studies the details mobility management schemes for small and medium scale femtocell network deployment. To do that, firstly we present two different network architectures for small scale and medium scale WCDMA femtocell deployment. The details handover call flow for these two network architectures and CAC scheme to minimize the unnecessary handovers are proposed for the integrated femtocell/macrocell networks. The numerical analysis for the proposed M/M/N/N queuing scheme and the simulation results of the proposed CAC scheme demonstrate the handover call control performances for femtocell environment.

• 한국인터넷방송통신학회논문지
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• 제14권6호
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• pp.303-308
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• 2014

이 논문은 대학 웹진 현황을 토대로 웹진의 목적과 어떤 기능을 담당하는지 사용자 인터페이스 디자인 측면에서 다루고자 한다. 이를 위해 웹진의 내용적 측면과 사용자 중심의 콘텐츠 구성과 컬러 및 내비게이션 디자인 측면에서 조사해 보았다. 조사를 통해, 향후 효과적인 대학 웹진 제작을 위해 사용자와 제작자가 어떤 점에 유의하고 참고하여 디자인해야하는지 알아보고자 하였다. 웹진 제작자와 사용자의 상호 적극적인 커뮤니케이션을 활성화하고 공감하기 위해 웹진이 주요한 기능을 하고 있는지 조사를 통해 알 수 있었으며, 웹진의 이런 특성을 살려 제작한 대학들은 사용자 인터페이스 디자인 측면에서도 우수함을 알 수 있었다.