• 한국환경복원기술학회지
• /
• 제22권3호
• /
• pp.55-71
• /
• 2019

The purpose of this study is to propose an evaluation method to assess green environments of streetscapes to improve urban street green spaces in Jeonju City. Through a rapid assessment of urban street green spaces, we suggest an objective basis for expanding street green space as well as for adopting sustainable maintenance and improvement measures. We choose 12 sections of streetscapes (roads and sidewalks) to investigate existing street conditions which have more than four lanes and function as major road axes. Six large roads and six medium roads of Jeonju City center area are investigated as pilot assessment study sites. Site inventory checklists consist of environmental characteristics of streetscape, street tree status, and planting condition evaluation. Environmental characteristics of streetscapes are composed of physical and neighborhood factors. For instance, items for physical factors are types and width of road/sidewalks, paving materials, tree protection materials, and green strip. And surrounding landuse is a neighborhood factor. Assessment items for street tree status are street plant names (tree/shrubs/ground cover), size, and planting intervals. Planting condition evaluation items are tree shape, damage, canopy density, and planting types with existence of adjacent green space. Evaluation results are classified into three levels such as A(maintain or repair), B(greening enhancement), and C(structural improvement). In case of grade A, streetscapes have enough sidewalk width for maintaining green strip and a multi-layered planting(in large road only) with fairly good growing conditions of street trees. For grade B and C, streetscapes have a moderate level of sidewalk width with a single street tree planting. In addition, street tree growing conditions are appeared poor so that green enhancement or maintenance measures are needed. For median, only grade B and C are found as its planting growing foundations are very limited in space. As a result, acquiring enough sidewalk space is essential to enhance ecological quality of urban street green. Especially, it is necessary to have green strip with reasonable widths for plant growing conditions in sidewalks. In addition, we need to consider native species with multi-layer plant compositions while designing street green.

• 한국군사과학기술학회지
• /
• 제18권5호
• /
• pp.594-601
• /
• 2015

The purpose of this research is to propose a maintenance support system for deciding assembly sequence of the product and appropriate tools that are used to assembly and disassembly of parts in the product when geometric properties of the product. The digital maintenance system (DMS) is developed to generate the maintenance guideline and the initial experiment is conducted especially for an underwater weapon system with cylindrical structure. DMS considers four factors to find the efficient assembly and disassembly procedure automatically: (1) assembly tree, (2) properties of each part, (3) distance from the center of the product, and (4) volume. Based on the factors, DMS simulate the movement of each tool virtually and the properties of tools are investigated to find an appropriate tool for using assembly and disassembly of each part in the product. The proposed approach integrates modeling, simulation, data configuration, and virtual reality to allow a development of preliminary maintenance guidance.

• 시스템엔지니어링학술지
• /
• 제9권1호
• /
• pp.65-84
• /
• 2013

This paper introduces a systems engineering approach to reliability centered maintenance to address some of the weaknesses. Reliability centered maintenance is a systematic, disciplined process that produces an efficient equipment management strategy to reduce the probability of failure [1]. The study identifies the need for RCM, requirements analysis, design for RCM implementation. Value modeling is used to evaluate the value measures of RCM. The system boundary for the study has been selected as containment spray pump and its motor drive. Failure Mode and Criticality Effects analysis is applied to evaluate the failure modes while the logic tree diagram used to determine the optimum maintenance strategy. It is concluded that condition based maintenance tasks should be enhanced to reduce component degradation and thus improve reliability and availability of the component. It is recommended to apply time directed tasks to age related failures and failure finding tasks to hidden failures.

• 한국조경학회지
• /
• 제30권4호
• /
• pp.92-104
• /
• 2002

This study investigates, analyzes, and summarizes Dansplantation techniques and methods through practical methodology centering on fieldwork in order to present effective planting methods for large trees that have important significance. The conclusions are as follows : 1. The transplantation process of a large tree generally consists of the stages of digging up a tree, manufacturing a carrier frame, loading the tee on a vehicle, transporting, transplanting the tree, installing a strut and maintaining and managing the new transplant. In addition, planting a tree on a mounted place includes the primary procedures of trimming out the root, and preparing for transplanting the tree on a mounted place, as well as the secondary work of trimming out the root, transplanting a tree on a mounted place, maintenance and management. 2. In order to decide on a transplantation method for a large-sized tree, a structure calculation has to be performed first. That is, one must calculate the weight of the tree and the allowable stress of the strut (H-beam, etc.) fhst and then decide on the upper method through computer modeling based upon this structural calculation. 3. As a result of the analysis of a transplanted tree using the life soil method, it was confirmed that large quantities of feeder roots had developed around the root within a short time after the transplantation. The life soil method has proven to be very effective for transplantation of large-sized trees. 4. As for the production method of an H-beam strut frame, it was found that the manufacturing process and disassembly process were simple and proper; therefore, the H-beam frame is an appropriate structure to be used in the transplantation of large trees. 5. The concavo-convex method, which consists of filling the life soil in the concavo-convex area around the root, was found to be a method that promotes the growth of feeder roots within a short period of time and saves the supply of water at the same time.

• Spatial Information Research
• /
• 제8권1호
• /
• pp.155-170
• /
• 2000

공간 인덱스인 R-Tree를 이용하여 조건에 만족하는 공간 객체를 찾기 위해서 MBR의 비교하는 여과 과정만으로는 부정확한 경우가 있으며 그러한 경우에는 해당 공간 객체를 읽어 조건과 직접 비교하는 과정, 즉 정제과정이 필요하게 된다. 정제과정을 수행하기 위해서는 디스크 입출력이 요구되고 고비용 공간 연상을 수행해야 하므로 이는 검색 비용이 커지는 요인이 된다. 그래서, 여과 과정후의 후보 객체수를 최소화하기 위한 2단계 여과 기법들이 연구되었지만, 여과 효율이 떨어지거나, 추가로 데이터를 유지해야하거나, 원래 객체의 정보를 잃어버려 객체들을 재구성해야하는 문제점이 발생한다. 따라서, 본 논문에서는 이차 여과 과정에서 공간 객체의 존재여부를 저장하는 진위 테이블인 그리드 필터를 이용하여 간단한 논리 연산만으로 공간객체를 검색할 수 있도록 하는 확장된 R-Tree를 제안한다. 그러므로, 그리드 필터를 가지는 확장된 R-Tree 는 효율적인 이차 여과과정을 수행하기 때문에 여과를 위한 연산비용이 작고, 근사의 질이 높아 여과 효율이 우수하다.

• 정보처리학회논문지C
• /
• 제10C권1호
• /
• pp.77-86
• /
• 2003

본 논문은 MPLS(Multiprotocol Label Swtiching) 망에서 인터넷 멀티캐스트 라우팅 프로토콜을 지원하기 위한 방안을 제시한다. 인터넷 멀티캐스트 라우팅 프로토콜은 트리의 구성방식과 속성에 따라 최단거리트리 방식, 공유트리 방식 및 복합트리 방식 등으로 분류된다. 각 방식에 따라 MPLS 망에서 지원해야 하는 기능이 달라진다. 특히, 단/양방향성 트리 링크, Flooding/Prune 방식의 트리 구성, 하나의 멀티캐스트 그룹에 다중 트리의 존재 등 여러 가지 미해결이거나 해결하기 어려운 문제점들이 존재한다. 본 논문에서는 몇가지 가정을 세우고, 이를 바탕으로 각 멀티캐스트 라우팅 프로토콜을 MPLS 망에서 지원하기 위한 방안을 제시한다. Flooding/Prune 방식의 멀티캐스트 라우팅 프로토콜에 대해서는 새로이 브로드캐스팅용의 레이블을 정의하여 해결하고, 공유트리 방식에 대해서는 기 제안된 블록기반 멀티캐스트 전송기법을 도입하여 셀 인터리빙(Call Interleaving) 문제를 해결하며, 마지막으로 복합트리 방식에 대해서는 기존 멀티캐스트 라우팅 프로토콜에 수정된 SPT 전환 기능을 추가하므로써 MPLS 지원문제를 해결한다. 제안하는 방법이 기존의 방법보다 비교해 보았을 때 전송지연에서 우수한 성능을 보임을 모의 실험을 통해서 확인하였다.

• 한국조경학회지
• /
• 제28권5호
• /
• pp.93-103
• /
• 2000

This research is to propose a rational criterion of the selection and the management f the roadside trees, and to establish the planting design and system with the objective of improving the roadside environment. All of the roadside trees in each objective courses in Kangnung, and the soil disposition, hardness of the soil in the planting areas have been investigated. Also, we have surveyed the kinds of the trees which kandgnung inhabitants want. The conclusion is as follows Most of roadsides have trees, but they need the introduction of shrubs or ground covering plants according to the locations and the environmental conditions. We have selected nineteen species in regard to the roadside tree criterion and the growing conditions living in Kangnung. It is desirable that we make banding style planting space between each roadside tree to improve the low ratio of green coverage. We have found out that Ligustrum obtusifolium, Buxus micropnylla, Euonymus japonica, Rhododendron schlippenbachii, Phyllostachys nigro and Rosa rugosa, ect. are suitable. In order to soften and weaken the rigidity of the hard substances on a paved roadside, the climbers such as the perennial herbaceous flowering and hedera rhombea should be preferred rather than annual herbaceous flowering because of curtailment of expenditure. To posses a systematical greenery frame in kangnung, we have planned a planting design system that would expand the greenery space every year. Moreover, we have to make a plan to overcome space restrictions. We have established a flexible plan considering the roadside conditions and the improved standard planting methods with an ultimate aim to create a special roadside view.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권5호
• /
• pp.1932-1950
• /
• 2018

The paper proposes a code-clone detection method that gives the highest possible precision and recall, without giving much attention to efficiency and scalability. The goal is to automatically create a reliable reference corpus that can be used as a basis for evaluating the precision and recall of clone detection tools. The algorithm takes an abstract-syntax-tree representation of source code and thoroughly examines every possible pair of all duplicate tree patterns in the tree, while avoiding unnecessary and duplicated comparisons wherever possible. The largest possible duplicate patterns are then collected in the set of pattern clusters that are used to identify code clones. The method is implemented and evaluated for a standard set of open-source Java applications. The experimental result shows very high precision and recall. False-negative clones missed by our method are all non-contiguous clones. Finally, the concept of neighbor patterns, which can be used to improve recall by detecting non-contiguous clones and intertwined clones, is proposed.

• 한국인공지능학회지
• /
• 제10권1호
• /
• pp.9-14
• /
• 2022

The demand for public bicycles operated by the Seoul Metropolitan Government is increasing every year. The size of the Seoul public bicycle project, which first started with about 5,600 units, increased to 3,7500 units as of September 2021, and the number of members is also increasing every year. However, as the size of the project grows, excessive budget spending and deficit problems are emerging for public bicycle projects, and new bicycles, rental office costs, and bicycle maintenance costs are blamed for the deficit. In this paper, the Azure Machine Learning Studio program and the Boosted Decision Tree Regression technique are used to predict the number of public bicycle rental over environmental factors and time. Predicted results it was confirmed that the demand for public bicycles was high in the season except for winter, and the demand for public bicycles was the highest at 6 p.m. In addition, in this paper compare four additional regression algorithms in addition to the Boosted Decision Tree Regression algorithm to measure algorithm performance. The results showed high accuracy in the order of the First Boosted Decision Tree Regression Algorithm (0.878802), second Decision Forest Regression (0.838232), third Poison Regression (0.62699), and fourth Linear Regression (0.618773). Based on these predictions, it is expected that more public bicycles will be placed at rental stations near public transportation to meet the growing demand for commuting hours and that more bicycles will be placed in rental stations in summer than winter and the life of bicycles can be extended in winter.

• 아시안잔디학회지
• /
• 제16권2호
• /
• pp.85-96
• /
• 2002

This study showed the current plantation of woody landscape plants of 42 school gardens in Daejeon metropolitan city. The ratio between evergreen tree and deciduous tree was 67% to 33%. The ratio between evergreen shrub and deciduous shrub was 48% to 52%. Also, 161 kinds of woody species were found; evergreen tree was 21 species, deciduous tree was 67 species, evergreen shrub was 16 species, deciduous shrub was 44 species, and vine and the others were 13 species. The proportion of native woody species was 61% (98 out of 161 species). 110 species were planted at the front garden area. In the mid-garden, 77 kinds of woody species were found. In the side garden, 95 kinds of woody species were found. In the rear garden, 92 kinds of woody species were found. The surrounding of play ground and outer area were planted 82 species. The first ranked evergreen tree was Juniperus chinensis‘Kaizuka’. And Deciduous tree, evergreen shrub, deciduous shrub, and vine showed Gingko biloba, Buxus microphylla var. koreana, Hibiscus syriacus, Wisteria floribunda, respectively. The school symbol of tree and flower was planted in 41 schools. The first rank plants of school symbol tree and flower were Pinus densiflora, Forsythia koreana and Rosa spp. Plant nameplate was found at 22 schools. The plant nameplate was used for 1∼10 species at 17 schools. In conclusion, plantation of landscape trees should be considered characteristic of each school area. In addition, school landscape should be planned distinction of a elementary school, a middle school, a high school, and a school for handicapped. School landscape should be considered carefully from functional, natural, educational environment and maintenance viewpoints as well as urban forest networking.