• Asian-Australasian Journal of Animal Sciences
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• 제24권5호
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• pp.587-602
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• 2011

Improved efficiency in the use of natural resources, pragmatic production systems and environmental sustainability, justified by the need for improved land use systems and increased productivity, are discussed in the context of Asian integrated systems, diversification, and issues of sustainability. The importance of these are reflected by serious inadequate animal protein production throughout Asia, where available supplies cannot match current and projected human requirements up to 2050. Among the ruminant production systems, integrated tree crops-ruminant production systems are grossly underestimated and merit emphasis and expansion. As an example, integrated oil palm- based system is an important pathway for integration with ruminants (buffaloes, cattle, goats and sheep), and provides the entry point for development. The importance and benefits of integrated systems are discussed, involving animals with annual and perennial tree crops, integration with aquaculture, the significance of crop-animal interactions, stratification of the systems, production options, improved use of forages and legumes, potential for enhanced productivity, implications for improved livelihoods of the rural poor and the stability of farm households. The advances in research and development in South East Asia highlight demonstrable increased productivity from animals and meat offtakes, value addition to the oil palm crop, sustainable development, and distinct economic impacts. The results from 12 out of a total of 24 case studies concerning oil palm over the past three decades showed increased yield of 0.49-3.52 mt of fresh fruit bunches (FFB)/ha/yr; increased income by about 30%; savings in weeding costs by 47- 60% equivalent to 21-62 RM/ha/yr; and an internal rate of return of 19% based on actual field data. The results provide important socio-economic benefits for resource-poor small farmers. Potential increased offtakes and additional income exist with the integration of goats. Additionally, the potential for carbon sequestration with tree crops is an advantage. The reasons for low adoption of the syatems are poor awareness of the potential of integrated systems, resistance by the crop- oriented plantation sector, and inadequate technology application. Promoting wider expansion and adoption of the systems in the future is linked directly with coherent policy, institutional commitment, increased investments, private sector involvement, and a stimulus package of incentives.

• 한국전자통신학회논문지
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• 제15권1호
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• pp.45-52
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• 2020

본 논문에서는 저장 및 검색 성능과 보안을 고려하여 key-value 형태의 SSD를 활용한 RDF 데이터 저장 및 검색 문제에 대한 해결책을 제안한다. Key-value SSD를 사용한 RDF 데이터 셋으로 부터 논리 관계와 실제 값을 분리하기 위한 2단계 압축 알고리즘을 제안한다. 이는 압축 및 저장 성능뿐만 아니라 보안도 향상시킨다. 우리는 또한 검색 성능 향상과 병합정렬 조인 알고리즘 구현을 위한 R∗-tree 기반 하이브리드 검색 구조를 제안했으며, R∗-tree 검색 효율성에 영향을 미치는 요인들에 대해 설명한다. 논문에서 제안된 방식은 기존의 압축 및 저장 그리고 검색 접근 방식보다 저장 공간을 적게 차지하면서 더 빠른 결과를 얻을 수 있으며, 다양성, 유연성, 그리고 보안 측면에서 더 우수한 경쟁력을 가진다.

• ETRI Journal
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• 제28권3호
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• pp.329-336
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• 2006

This paper investigates the problem of protecting multicast sessions in mesh wavelength-division multiplexing (WDM) networks against single link failures, for example, a fiber cut in optical networks. First, we study the two characteristics of multicast sessions in mesh WDM networks with sparse light splitter configuration. Traditionally, a multicast tree does not contain any circles, and the first characteristic is that a multicast tree has better performance if it contains some circles. Note that a multicast tree has several branches. If a path is added between the leave nodes on different branches, the segment between them on the multicast tree is protected. Based the two characteristics, the survivable multicast sessions routing problem is formulated into an Integer Linear Programming (ILP). Then, a heuristic algorithm, named the adaptive shared segment protection (ASSP) algorithm, is proposed for multicast sessions. The ASSP algorithm need not previously identify the segments for a multicast tree. The segments are determined during the algorithm process. Comparisons are made between the ASSP and two other reported schemes, link disjoint trees (LDT) and shared disjoint paths (SDP), in terms of blocking probability and resource cost on CERNET and USNET topologies. Simulations show that the ASSP algorithm has better performance than other existing schemes.

• 대한원격탐사학회지
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• 제39권5_4호
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• pp.1165-1172
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• 2023

최근 우리나라는 2050 탄소중립을 선언하였고, 산림청에서는 첨단 정보통신기술을 접목하여 디지털트윈 기반으로 산림자원 관리, 산림재해 예방 등을 위한 K-포레스트 추진계획을 발표하였으며, 드론, LiDAR 등의 활용으로 산림자원 조사의 정밀화 및 첨단화를 추진하고 있다. 이처럼 산림자원 관리에 대한 요구가 증가하고 있으며 산림공간의 디지털트윈 구축 필요성이 높아지고 있다. 그러나 현재까지 우리나라의 디지털트윈은 도시 및 전국단위 디지털트윈 환경인 가상도시 서비스만을 구축 및 제공하고 있으며, 산림 공간을 대상으로하는 3차원 디지털트윈 서비스는 운영 및 제공되고 있지 않다. 이에 본 연구에서는 수목 단위의 수고, 흉고직경과 같은 수직적 정보에 해당하는 3차원 산림공간정보 서비스 제공을 위한 산림 디지털트윈 환경을 구현하고자 하였으며, 실감형 3D 나무모델의 경량화, 3D Tiles 적용으로 3차원 산림공간정보 서비스를 위한 산림 디지털트윈 환경 구현 가능성을 확인하였다. 지속적인 연구를 통하여 도심지 내의 가로수를 포함해 전국단위 수목을 대상으로 3D 나무모델 배치 및 서비스 가능한 산림 디지털트윈 구현할 예정이며, 이를 통하여 산림자원 관리를 위한 산림 디지털트윈 서비스 개발이 가능할 것으로 기대된다.

• 한국통신학회논문지
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• 제34권3B호
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• pp.225-234
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• 2009

Recently IPTV service is penetrating to the ordinary home users very swiftly. One of the first phase of IPTV service is considered to be VoD, and a nationwide availability of the VoD service imposes tremendous pressure to the network resource due to its requirements for the broad bandwidth, the inherent nature of unicast technology, and the large scalability, etc. This work suggests a novel and practical method to the design of network resource for the VoD service. Especially, we explore the distributed content storage problem that takes into account the popularity of the video contents and its corresponding link dimensioning problem that takes into account the grade of service for the flow level quality of service about the VoD service. By assuming a realistic topology for the nationwide IP backbone network of Korea, which is a typical tree topology, we suggest an analytic method for the design of VoD service.

• 한국멀티미디어학회논문지
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• 제6권2호
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• pp.183-193
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• 2003

이동형 단말 시스템에서 XML 데이터의 역할과 데이터베이스의 지원이 중요해지고 있다. 이에 따라, 내장형 XML 데이터베이스 시스템에 대한 연구가 활발하다. XML문서를 처리하기 위해서는 DOM API를 지원할 필요가 있는데, 기존의 DOM API는 DOM 트리를 메모리에 유지한다. 이것은 제한된 리소스를 가지는 내장형 시스템 을 안정적으로 운용하는데 위협적인 요소이다. 본 논문에서는 내장형 시스템의 부족한 리소스를 고려하여 DOM 트리를 메모리가 아닌 내장형 데이터베이스 시스템인 버클리 DB위에서 구성되는 P-DOM 트리를 제안하고, 이를 관리하는 DOMdbm 시스템을 개발한다.

• 한국임상수의학회지
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• 제25권4호
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• pp.268-273
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• 2008

For evaluation of immune stimulation effect of lacquer tree extracts, lymphocytes were counted by labeling of FITC-conjugated monoclonal antibody in the pheripheral blood of pigs that fed with a fodder supplemented by lacquer tree extracts. Populations of MHC-II+, CD4+, and CD8+T lymphocytes were increased more than 2% level after 1 week feed supply of the lacquer tree extracts. The increase of those T cells reached at maximum level after 2 weeks in the tested group. B lympyocytes with surface IgM were increased 5% after 1 week feed supply of the lacquer tree extracts, and their numbers reached maximum after 2 weeks in the tested group. For the assessment of cytotoxicity of the lacquer tree extracts, morphological changes were examined on the epithelial cells of small intestine from pigs fed with a fodder supplemented by 0.1 % lacquer tree extracts for 6 weeks (the tested group). Thin-sectioned tissue of small intestine was fixed with glutaraldehyde, then coated with gold particles, and the specimen was examined under scanning electron microscope. The villi on the mucus membrane of jejunum and ileum from the tested pigswere enlarged on the tip and were linked each other.

• 한국환경과학회지
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• 제11권11호
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• pp.1149-1156
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• 2002

The ecological characteristics of Dolbae trees, a valuable genetic resource for native pyrus fruit trees, were investigated at four naturally inhabited areas on Mount Kaya, Gyeongsangnam-Do. Most Dolbae trees were found on the southwest side of an old hiking path to a mountain valley at altitudes of 610∼670 m. The surrounding flora consisted of 46 families, 69 genera, 75 species, and 10 varieties. The natural habitat of the Dolbae trees was basically a deciduous broad-leaved forest with a predominance of Quercus serrata and ligneous plants(xylophytes) from the Fagaceae and Betulaceae families. The habitat was also found to be in a second transition resulting from forest disturbance and exhibited a degree of diversity of 2.901-5.065, based on Shannon-Weiner's index. Examination of the Dolbae trees found in Mount Kaya revealed diameter breast heights(DBHs) ranging from 10 to 60 cm, including six old and large Dolbae trees with a DBH of 50∼60 cm, which will be particularly valuable as a genetic resource. Accordingly, the current results suggest that the study areas are a secondary forest in a typical mid-temperate zone resulting from forest damage about 10 years earlier.

• 한국경영과학회지
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• 제38권2호
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• pp.141-157
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• 2013

In this paper, we consider the minimization of the total weighted earliness-tardiness penalty of jobs, regarding the partial precedences between jobs. We present an optimal scheduling algorithm in O(n(n+m log m)) where n is the number of jobs and m is the number of partial precedences. In the algorithm, the optimal schedule is constructed iteratively by considering each group of contiguous jobs as a block that is represented by a tree.

• 한국정보과학회논문지:시스템및이론
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• 제33권6호
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• pp.337-343
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• 2006

Stack Resource Policy (SRP)는 몇 가지 독특한 특성을 가진 실시간 동기화 프로토콜이다. 그 특성 중의 하나는 초기 수행 차단(early blocking)으로서, 공유자원을 요청하는 시점에 작업의 수행을 정지시키는 것이 아니라, 작업의 수행 시점 자체를 연기하도록 한다. SRP가 EDF와 같은 동적 우선순위 스케줄링 알고리즘과 같이 사용될 경우, 초기 수행 차단을 지원하기 위해 스케줄러는 수행이 블록(block)되지 않을 작업 중 가장 우선순위가 높은 작업을 선택해야 하며, 이러한 탐색 연산은 수행 오버헤드(runtime overhead)의 원인이 된다. 본 논문에서는 SRP와 EDF를 같이 사용할 때의 스케줄러 수행 오버헤드를 분석한다. 기존의 준비 큐(ready Dueue) 구현 방식과 탐색 알고리즘을 사용하면 작업의 수가 많아짐에 따라 작업 탐색 오버헤드가 매우 커진다. 이 문제를 해결하기 위하여, 본 논문은 스케줄러가 효율적으로 작업을 탐색할 수 있는 준비 큐 자료구조와 O([log$_2n$])의 복잡도를 가지는 작업 탐색 알고리즘을 제안한다.