• 현장농수산연구지
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• 제10권1호
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• pp.101-111
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• 2008

As the quality of life improves, people want to live in more pleasant environment with beautiful trees, clean air and water. They are keenly interested in environmental issues as well as living environment of apartment which is a trademark of modern life. With this situation, the function and roles of landscaping trees have been recognized as a critical factor to improve living environment. As people have asked for more demands on those trees, it has raised more issues on the defect of trees and is required the solution to those issues. So, the purpose of this study was to survey the reasons of defects and find out those solutions. The data on defects in 1990s was referenced to the reports issued by SH Corporation in 1994 and 1997. The data on defects in 2000s are collected from March, 2006 to May 2006 based on the survey for apartments already constructed by Korea Housing Corporation. The results of the survey were shown that, in the year of 1994, landscaping trees causing high rate of defects were Acer buergerianum (92%), Pinus densiflora(85.7%), Celtis sinensis(80%), Cydonia sinensis(75%) and Diospyros kaki(66.6%), and in the year of 1997, landscaping trees causing high rate of defect were Ziziphus jujuba(100%), Cornus alba(65.2%), Diospyros kaki(60%), Thuja occidentalis(60%), and Metasequoia glyptostroboides(42%). And, in the year of 2006, landscaping trees causing high rate of defect were Sophora japonica(100%), Taxus cuspidata(80%), Magnoila quinquepeta (75%), Acer palmatum(62.5%) and Ginkgo biloba(50%). Because the reasons of defects were various according to the conditions including the climate, location, time and landscaping trees carried into the work area, we present the problems and solutions to those defects. Since the landscaping trees are living creatures, the factors of defects were various and complicated according to the site condition. So, in the period of warranty, contractor should designate the tree manger who can recognize the situation and take suitable action within timely manner.

• 한국환경복원기술학회지
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• 제17권2호
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• pp.73-83
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• 2014

This study was conducted to evaluate defects in Zelkova serrata trees using an ultrasonic tomograph (PICUS) and suggest a management plan to maintain it as a natural and cultural resource. In previous study, health information of 16 protected trees were obtained by surveying the following categories; tree appearance, crown, bark, root exposure, water and nutrition, deterioration, pest, vitality, ground status, and pollutant. The average score of health was 16.5 in 16 trees, which means that general monitor is needed for management. In this study, the evaluation result of tree's inside defects using an ultrasonic tomograph showed that 43.8% of decay rate has been found in 16 trees. In fact, some trees look to be good even though they actually have a defects causing broken by natural disaster such as strong wind. Therefore, it is urgent to put some support to the trees and come up with a protective plan. The results of this study would be useful as basic data in developing a guideline for the efficient conservation and management of big and old trees.

• 한국조경학회지
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• 제29권2호
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• pp.61-67
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• 2001

The purpose of this thesis was to provide the basic data for landscape architecture of apartment constructions and to minimize the users´ and builder´ loss in terms of finance and landscape due to defects in planting. After a review of literature related to defects of planting work, the researcher investigated the defects in planting of landscape plants on the basis of data from the drawing and defect-repair construction of 50 civil apartment complexes in Daegu and Kyongbook are from 1994 to 1998. The defect-ratio was analysed in terms of the species, shapes, and sizes of trees. It provides matters for consideration in terms of the design of the landscape planting on the apartment unit. It also provided the future directions for landscape architecture in apartment constructions with regard to the selection of the planting trees, etc., given statistics on defect occurrence. The causes of defect of the landscape planting trees were not studied accurately in this study due to the board range of researched area, the differences of the planting ground environment, the management ability, and the parameters of judging planting defects. It is recommended that those areas should be researched in the future.

• 한국환경생태학회지
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• 제36권5호
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• pp.535-549
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• 2022

강풍, 폭우 등 이상기후의 대형화와 빈도 증가로 인해 나무가 부러지거나 쓰러지는 훼손이 증가하고 있으나 나무 내부의 공동, 부후 등 구조적 결함은 육안조사로 판별이 어렵기 때문에 예측을 통한 사전대응에 한계가 있다. 비파괴음파단층촬영은 나무에 미치는 물리적 훼손을 최소화하면서 내부결함을 추정하는 방법으로 내부결함 진단에 효율적이나 수종별 정확도에 차이가 발생하기 때문에 현장적용 전 측정결과의 신뢰성 분석이 선행되어야 한다. 이번 연구는 우리나라 대표 수종인 소나무와 은행나무 노거수를 대상으로 음파단층촬영의 신뢰성 검증을 위해 침입성 드릴저항 측정을 교차 적용하여 목재 내부결함을 측정하고 평가결과를 비교하였다. 두 집단 간 결함부 측정 평균값에 대한 t검정 결과 소나무는 통계적으로 유의한 차이가 없는 반면, 은행나무는 유의성에 차이가 있었다. 선형회귀분석 결과 두 수종 모두 드릴저항그래프의 결함이 증가할 때 음파단층영상 결함이 증가하는 양의 상관관계를 보였다.

• 인간식물환경학회지
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• 제23권3호
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• pp.347-362
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• 2020

Background and objective: It is difficult to conclusively determine the exact cause of tree defects since multiple causes are involved such as climate change, plantation, tree quality and planting time, construction, planting base, drainage, sunshine conditions, maintenance, and microclimate. The data related to landscaping construction defects are scattered or fragmented by companies and years, but not managed systematically by the defect information management system. Most of the earlier studies associated with tree defects in apartment complexes suggested defect rates after examining tree defects in the completed construction site and proposed fragmentary and subjective conclusions about the causes of defects observed in trees with high defect rates. It is proposed to continue to conduct studies on the establishment and analysis of systematic databases to identify the exact causes of tree defects and measures to improve, and the need to accumulate systematic data in the construction process where many defects arises. This study was conducted to reduce the defects of trees planted in apartment complexes. Methods: Main factors related to tree defects were subdivided based on the results of literature review and a defect investigation at the completion site, and tree history management items were selected and subdivided during the construction stage. Results: The criteria for the preparation of subdivided items were obtained, and the tree history management checklist was written for the site under actual construction and a systematic database was established. Items that are categorized based to the causes of defects include the location of nurseries, date, tree quality, site conditions, planting techniques, microclimates, and maintenance. Conclusion: This study suggested tree history management items based on the tree defects that can be identified at the construction stage and applied them to the selected study site, which differentiates this study from earlier studies. It will be necessary to conduct a comprehensive and objective time series analysis on tree defects that occur over time by continuously monitoring and collecting data after construction.

• 한국융합학회논문지
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• 제13권2호
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• pp.249-255
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• 2022

본 연구는 최근 가공 불량 예측 방법으로 주목받고 있는 머신러닝 기반의 모델을 이용하여 CNC 가공 불량 발생의 실시간 예측을 위한 분석 프레임워크를 제안하고, 해당 프레임워크에 기반하여 XGBoost, CatBoost, LightGBM, 랜덤 포레스트, Extra Trees, SVM, k-최근접 이웃, 로지스틱 회귀 모델을 CNC 설비에 기본 내장된 센서들로부터 추출된 데이터에 적용 및 분석하였다. 분석 결과 XGBoost, CatBoost, LightGBM 모델이 동일하게 가장 우수한 정확도, 정밀도, 재현율, F1 점수, AUC 값을 보였으며, 이 중 LightGBM 모델이 소요 실행 시간이 가장 짧은 것으로 나타났다. 이러한 짧은 소요 실행 시간은 실 시스템 구축 비용 절감, 빠른 불량 예측에 따른 CNC 장비 파손 확률 감소, 전체적인 CNC 활용률 증가 등의 실무적 장점을 가지므로 LightGBM 모델이 기본 센서들만 설치된 CNC 설비에 적용 시 가공 불량 예측에 가장 효과적으로 판단된다. 또한 소요 실행 시간 및 컴퓨팅 파워의 제약이 없는 상황에서는 LightGBM, Extra Trees, k-최근접 이웃, 로지스틱 회귀 모형으로 구성된 앙상블 모델을 적용할 경우 분류 성능이 최대화됨을 확인하였다.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.22-30
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• 2003

This study was performed to obtain the basic data for high quality timber production and efficient utilization by investigating the effect of pruning on timber quality of domestic plantation-grown Korean pine (Pinus koraiensis Sieb. et Zucc.). The results were summarized as follows:Dead knots (unsound knots) in the pruned logs occurred more at upper parts when compared with in non-pruned ones. The numbers of knots on surface in heavily pruned trees were less than those in non-pruned trees, but there was no significant difference in moderately pruned trees. The required period to reveal clear timber surface without defects after pruning increased proportionally with the increase of knot diameter. The yield of clear lumber production increased by about 10% after 14 years from moderate pruning. The quality grade of log improved with more pruning practices. Knots appeared the most important factor in lowering the log grades.

• 헤리티지:역사와 과학
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• 제56권1호
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• pp.118-130
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• 2023

노거수 내부의 대규모 공동이나 부후는 나무가 쓰러지거나 부러지는 주요 원인 중 하나로, 구조적으로 약해진 나무는 강풍이나 폭설에 더욱 취약하다. 특히 노거수는 강풍, 폭설 등과 같은 외부 충격 발생 시 피해 가능성이 상대적으로 더 높고 한번 훼손되면 회복이 어렵기 때문에 예방적 관리가 중요하다. 이에, 천연기념물 이팝나무 7개소를 대상으로 육안교목평가(VTA)와 나무단층영상촬영을 실시하여 노거수의 물리적 생육상태를 평가하였다. 육안교목평가 결과, 상대적으로 '양산 신전리 이팝나무'와 '순천 평중리 이팝나무', '광양읍수와 이팝나무'는 가지의 연결각도가 좁고, 부착력이 약한 것으로 분석되었으나 수관이 왜소하고 하중 부담이 낮아 추가적인 보호시설 설치보다는 위험징후에 대한 정기 모니터링이 필요한 것으로 나타났다. 나무단층영상촬영 결과 이팝나무 전체적으로 내부에 공동이 탐지되었고 '순천 평중리 이팝나무(70.8%)', '고창 중산리 이팝나무(66.8%)', '광양읍수와 이팝나무(56.9%)' 순으로 공동이나 부후로 추정되는 면적이 넓은 것으로 조사되었다.

• 한국조경학회지
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• 제44권5호
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• pp.59-67
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• 2016

공공기관의 조경공사 설계시에는 일반적으로 조달청에서 고시하는 조경수목 가격을 반영하나, 수목 식재시 조달청에서 정한 세근발달 재배품이라는 규정이 거의 준수되지 않고 있는 실정이다. 규정을 준수하면서 하자율을 줄일 수 있는 조경수 생산의 신기술, 신제품인 지중 매립형 컨테이너 모듈의 성능을 평가하기 위하여 단근 후 3개월간의 세근 발생밀도, 세근발달 길이 및 굴취시 세근 유지율, 수목의 생육 지장 여부에 대하여 일반노지 단근과 컨테이너 용기 지상재배와 비교 연구하였으며, 그 결과는 다음과 같다. 첫째, 세근 발생의 밀도는 컨테이너 모듈을 사용한 조경수에서는 88%로 매우 높게 나타났으며, 일반 노지 단근은 64%로 상대적으로 낮았고, 컨테이너 용기를 이용한 지상재배 조경수는 고사하여 측정의 의미가 없었다. 둘째, 조경수의 세근발달과 세근 유지율은 컨테이너 모듈의 경우, 평균 길이는 10.4cm, 세근 유지율은 100%로서 굴취에 의한 세근의 손상은 없었으며, 노지 단근의 경우 평균 길이는 25.6cm, 세근 유지율은 56%로 컨테이너 모듈의 절반 수준으로 훼손이 큰 것으로 나타났다. 컨테이너 용기 조경수의 세근발달은 전혀 이루어지지 않았다. 셋째, 컨테이너 모듈과 일반 노지 단근의 경우, 단근 작업에 따른 수목의 고사 또는 왜소엽 등의 지장이 전혀 없었다. 반면에 컨테이너 용기의 경우, 거의 전량이 고사하여 수목생육에 지장이 심각한 것으로 확인되었다. 이상에서, 지중매립형 컨테이너 모듈의 성능을 평가해 본 결과, 세 가지 모델 중 가장 우수한 것으로 확인되었으며, 컨테이너 모듈이 여름철 부적기 식재나 생육조건이 불리한 환경에서 수목의 빠른 초기 활착을 유도함으로써 하자를 예방하고, 조달청 규정 등에서 제시하고 있는 원칙을 준수할 수 있는 최적의 대안이 될 수 있을 것으로 기대한다.

• 농촌계획
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• 제8권3호
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• pp.49-57
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• 2002

The purpose of this study is to present a new orientation for the residential culture that can meet the shifting demands of modern people as their attitudes toward life change. One of the rural regions that has lately attracted considerable attention, Wonsam-myun, Yongin city, is selected as the residence zone to develop a housing complex. In this study, a new housing complex is designed to supplement the defects of existing housing complexes by making the utmost use of the merits that Wonsam-myun as a residential environment can offer. The major findings of this study can be summarized as follows: 1. To present a new Korean model, yellow soil houses and traditional trees were used to utilize Korea's traditional landscape beauty in the construction and landscape aspect, instead of imitating indiscreetly foreign styles in which most newly developed housing complexes were built. 2. To provide convenience to prospective residents, a package sales scheme covering from lot purchase to building permit was adopted. 3. As for the planting plan, existing plants was preserved as much as possible to keep harmony with new plants. In selecting plant types, a traditional method that emphasizes on the visual effects of aesthetic plants and shade trees with the change of seasons and plants various kinds of plants according to directions was adopted. 4. Each household was given the opportunity to design its own garden according to the family's preference and taste. 5. The advantages of a rural area that city does not offer were fully utilized to provide the residents with convenience and pleasure of living.