• ETRI Journal
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• 제43권3호
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• pp.524-537
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• 2021

High-performance Linpack (HPL) is among the most popular benchmarks for evaluating the capabilities of computing systems and has been used as a standard to compare the performance of computing systems since the early 1980s. In the initial system-design stage, it is critical to estimate the capabilities of a system quickly and accurately. However, the original HPL mathematical model based on a single core and single communication layer yields varying accuracy for modern processors and accelerators comprising large numbers of cores. To reduce the performance-estimation gap between the HPL model and an actual system, we propose a mathematical model for multi-communication layered HPL. The effectiveness of the proposed model is evaluated by applying it to a GPU cluster and well-known systems. The results reveal performance differences of 1.1% on a single GPU. The GPU cluster and well-known large system show 5.5% and 4.1% differences on average, respectively. Compared to the original HPL model, the proposed multi-communication layered HPL model provides performance estimates within a few seconds and a smaller error range from the processor/accelerator level to the large system level.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권12호
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• pp.1031-1051
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• 2006

최근 유비쿼터스 시스템을 설계하고 개발하기 위한 방법들 중 하나로서, 다중 에이전트 모델을 이용하는 방식이 연구되고 있다. 이러한 방식은 다중 에이전트 모델의 장점을 유비쿼터스시스템에서 수용할 수 있도록 하였다. 그러나, 특정 유비쿼터스 시스템에 대해서는 기존의 다중 에이전트 모델들만으로는 완벽하게 기술하기에 어려운 부분이 있다. 본 논문에서는 사용자의 요구가 동적으로 생성되면 개체들이 협업하여 이를 해결하는 협업 위주의 유비쿼터스 시스템에 초점을 맞추었다. 이러한 시스템에서는 서비스를 제공하기 위하여 형성되는 컴퓨팅 요소들간의 협업 조직이 매우 중요하지만, 일반적인 다중 에이전트 모델로는 이러한 협업 조직을 효과적으로 표현하기가 쉽지 않다. 즉, 기존의 모델만으로는 이러한 협업 조직의 동적인 생성과 소멸, 동적인 조직의 구성방식, 그리고 서비스를 제공하기 위한 조직 내에서 또한 조직들간의 협업 방식을 기술자기가 쉽지 않다는 것이다. 따라서 본 논문에서는 그러한 협업 조직을 커뮤니티라 하고, 협업 중심의 유비쿼터스 시스템을 커뮤니티에 기반하여 기술하는 추상화 모델로서 커뮤니티 컴퓨팅 모델을 제안하였다. 또한 본 논문에서는 유비쿼터스 시스템을 위한 체계적인 개발 체계가 수립되어 있지 않다는 점에 주목하고, 제안된 커뮤니티 컴퓨팅 모델을 기반으로 응용 시스템을 개발하기 위한 시스템 개발 과정을 제안하고 이를 빠르고 편리하게 도와주는 개발 도구를 구현하여 보았다. 마지막으로, 소규모의 유비쿼터스 시스템을 제안한 추상화 모델로 기술하고 개발 도구를 사용하여 다중 에이전트 플랫폼에서 개발하여, 제안한 방법의 실현성을 검증하여 보았다.

• 농촌계획
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• 제18권3호
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• pp.149-164
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• 2012

The purpose of the present study is to construct a rural development strategy from the nexus between spatial changes in specialized crops and suitable cultivation area of the crops. This paper pays particular attention to identify product life cycle of specialized crops in rural areas and estimate the impact of climate change on alterations in spatial distribution of the crops. In order to do so, first of all, this study applies multi-level model (Random coefficient model) to estimate the regional coefficient of five orchard crops. It utilizes the data 1995 to 2010 Korea Agricultural Census. Futhermore, it also adopts overlay analysis by ArcGIS to identify the development path of the crops and the relationship with climate change. Based on the results, it suggests a mechanism activating regional agriculture. The findings propose re-searching and relocating specialized regions of the crops. Especially, it proves each rural area can drive the new agricultural strategy to strengthen regional agriculture by estimating the relationship between development of specialized crops and suitable cultivation areas. For instance, shifting specialized crops in particular regions and enriching genetic or species varieties can be primary measures and it will contribute to improve the reliable base for income sources in the rural communities. This paper also offers specific policy implications regarding rural development plans in response to crops' life cycle and climate changes.

• 국제초고층학회논문집
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• 제6권2호
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• pp.149-163
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• 2017

With the intensification of urban development in Chinese cities, mixed land use in urban centers extends vertically into 3-D and expands its scale from a single building to commercial clusters. The multi-level pedestrian system in city centers also changed its role from one of traffic isolation to spatial integration, where transit nodes, street sidewalks, squares, building entrances, atriums, and corridors are interconnected, both horizontally and vertically, into a whole spatial system, within which pedestrian flows are guided and shopping facilities are arranged. This paper uses spatial configuration analysis of space syntax to examine the impacts of spatial patterns on movement distribution and the business performance of tenant mix in the multi-level commercial system of the Nanshan Commercial Cultural District in Shenzhen, China. The key objective is to better understand the interactions between the socio-economic variables and spatial design parameters of a shopping complex. The research findings point to the importance of multiplicity between syntactic variables and other spatial variables in influencing the pedestrian flows, business performance and tenant mix in highly complex commercial systems. Particularly noteworthy is the relationship between spatial accessibility measures and the location of escalators, and the ways in which individual commercial buildings are embedded into the overall spatial system. The study suggests that this may lead to the preliminary identification of the spatial qualities of effective vertical extensions of mixed land use in a high-density urban settings.

• 전력전자학회논문지
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• 제8권6호
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• pp.478-487
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• 2003

본 논문에서는 고압 대용량 전동기 구동용 멀티레벨 인버터의 종류 및 특징을 간략히 살펴보고, 특히 입출력 전력품질이 우수하고 전압별 시리즈화가 용이한 H-브릿지 멀티레벨 인버터의 구조적 특징 및 장점을 기술하였다. 연구 개발된 3,300V lMVA 용량의 Cascaded H-브릿지 멀티레벨 인버터의 구체적인 전력회로 구조 및 설계방법, 제어기 구성 그리고 PWM 기법을 제시하였다. 또한, 실용량의 시험을 통해 H-브릿지 멀티레벨 인버터는 출력 전압 Step이 여러 단계이고 dv/dt가 적으며 입력단 THD를 크게 낮출 수 있어 성능 면에서도 여타 방식보다 우수함을 입증하였다. 또한 생산적인 측면에서도 저압 소자를 사용하여 설계하므로 기존의 생산/시험 기술과 설비를 이용할 수 있어 매우 경제적이며 Power Cell 단위 결합 구조이므로 신뢰성 측면이나 보수/유지 측면에서도 유리하다는 결론을 얻었다.

• Journal of Microbiology and Biotechnology
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• 제30권6호
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• pp.793-803
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• 2020

Adaptive laboratory evolution (ALE) is an evolutionary engineering approach in artificial conditions that improves organisms through the imitation of natural evolution. Due to the development of multi-level omics technologies in recent decades, ALE can be performed for various purposes at the laboratory level. This review delineates the basics of the experimental design of ALE based on several ALE studies of industrial microbial strains and updates current strategies combined with progressed metabolic engineering, in silico modeling and automation to maximize the evolution efficiency. Moreover, the review sheds light on the applicability of ALE as a strain development approach that complies with non-recombinant preferences in various food industries. Overall, recent progress in the utilization of ALE for strain development leading to successful industrialization is discussed.

• 한국시뮬레이션학회논문지
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• 제24권1호
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• pp.9-16
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• 2015

본 논문에서는 표준연동 아키텍처(HLA/RTI)기반 다해상도 연동이 가능한 시뮬레이션을 구성하여 공학급(QUEST), 교전급(SADM), 임무급(EADSIM)의 모델을 연동하였다. 공학급 모델은 전투실험 공학분석 시범체계에서 개발된 전투실험 통합개발환경(QUEST)을 이용하여 모델을 개발하였다. 교전급 모델은 SADM을 이용하여 개발하고 임무급 모델은 EADSIM을 이용하여 모델을 개발하였다. 여러 계층의 모델을 연동하기 위해 표준 연동 아키텍처 기반(HLA/RTI)으로 설계하고 구현하였다. 각기 다른 분산된 환경에서 수행되고 있는 시뮬레이션 프로그램들이 상호 연동을 위해 표준 연동 인터페이스 명세에 만족하는 연동 시뮬레이션을 설계하고 각 시뮬레이션 프로그램 간의 중계 역할을 담당하는 통합연동 게이트웨이를 개발하였다. 다해상도 연동 시뮬레이션을 통해 여러 계층 간의 모델을 연동하여 해양 무기체계 효과도 분석을 위한 모델충실도를 향상하고 운용자 필요에 따라 요구되는 전장 환경을 신속하게 구성할 수 있다. 또한 표준연동 아키텍처(HLA/RTI)를 기반으로 설계하게 된 다른 시뮬레이션 프로그램과도 쉽고 효율적으로 연동할 수 있다.

• 센서학회지
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• 제22권1호
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• pp.18-27
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• 2013

Real-time monitoring is one of the prime necessities in a weapon flight test that is required for the efficient and timely collection of large amounts of high-rate sampled data acquired by an event-trigger. The wireless sensor network is a good candidate to resolve this requirement, especially considering the inhospitable environment of a weapon flight test. In this paper, we propose a priority based multi-channel MAC protocol with CSMA/CA over a single radio for a real-time monitoring of a weapon flight test. Multi-channel transmissions of nodes can improve the network performance in wireless sensor networks. Our proposed MAC protocol has two operation modes: Normal mode and Priority Mode. In the normal mode, the node exploits the normal CSMA/CA mechanism. In the priority mode, the node has one of three grades - Class A, B, and C. The node uses a different CSMA/CA mechanism according to its grade that is determined by a signal level. High grade nodes can exploit more channels and lower backoff exponents than low ones, which allow high grade nodes to obtain more transmission opportunities. In addition, it can guarantee successful transmission of important data generated by high grade nodes. Simulation results show that the proposed MAC exhibits excellent performance in an event-triggered real-time application.

• 한국가구학회지
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• 제26권4호
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• pp.356-363
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• 2015

Recently, the increase of single households are remarkable in Korean society due to various social and economic reasons such as aging and changes in values, and it is expected to bring many changes to social and economic structures and residential spaces. Increase of single households is a result of complex economic, cultural and social factors. It is because as the individual's financial independence increases due to elevated income and education level, the age of marriage is going up and the individualism, which values the individual's value rather than custom, is spreading. It is expected to accelerate further in connection with the changes in structure of population, such as a low birth rate and aging. As the number of single households is increasing, the development and marketing for single household products are actively growing. With the increase in consumption demand and need of growing single households, the multi-functional system furniture that can be efficiently and conveniently used in small spaces are needed, but the furniture manufactured in Korean companies are designed for regular housing and is not suitable for single households. Therefore, the aim of this study is to develop multi-functional system furniture can be freely used in the housing structure of single household and small spaces.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.264-265
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• 2006

The directions of further developments in the modeling of sintering are pointed out, including multi-scale modeling of sintering, on-line sintering damage criteria, particle agglomeration, sintering with phase transformations. A true multi-scale approach is applied for the development of a new meso-macro methodology for modeling of sintering. The developed macroscopic level computational framework envelopes the mesoscopic simulators. No closed forms of constitutive relationships are assumed for the parameters of the material. The model framework is able to predict the final dimensions of the sintered specimen on a global scale and identify the granular structure in any localized area for prediction of the material properties.