• 한국지리정보학회지
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• 제2권2호
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• pp.79-86
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• 1999

본 연구는 1995년 4월 5일 진주시 월아산지역에서 발생한 산화지를 1995년 5월에 관측된 Landsat TM화상 데이터로부터 산림내 피해지를 분류하고 그 입목손실량을 추정하기 위해서 실시되었다. 화상 데이터에서 11개의 GCP를 선정하여 Affine좌표변환식에 의해 TM지도좌표체계에 일치되도록 화상을 기하보정 처리한 후 공1차내삽법(bilinear interpolation)에 의해 재배열하였다. 재배열된 화상 데이타를 감독분류 중 최대우도법에 의해 토지이용구분을 실시하였다. 산화지로 분류된 지역과 비산화지로 분류된 인접지역 중 임상(Pinus thunbergii)과 지형이 동일한 지역을 GIS기법에 의해 추출하고 이 지역을 표준지로 선정하였다. 선정된 표준지를 중심으로 표준목의 재적과 수령을 Criterion laser estimator와 WinDENDRO$^{tm}$(v. 6.3b)시스템에 의해 분석하였다. 표준목의 흉고직경은 20.9cm, 수고는 9.7m, 재적은 $0.1396m^3$으로서 표준지의 임분재적은 $2.9316m^3$/0.04ha로 나타났으며, 산화지 218.4ha에서의 총 입목손실량은 $16,007m^3$로 평가되었다.

• 한국산림과학회지
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• 제96권6호
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• pp.742-749
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• 2007

본 연구의 목적은 거리독립생장모델을 이용한 잣나무 임분의 간벌효과 분석모델을 개발하는데 있다. 이 모델은 간벌시업계획의 주요 인자로 간벌의 횟수와 시기, 강도 그리고 간벌방법을 고려할 수 있도록 설계되었다. 개발된 모델의 적용성 검토를 위해 간벌시업계획에 따른 7개의 시나리오를 작성하여 임분생장 효과를 분석하였다. 연구결과, 개발된 모델을 이용하여 간벌시업 형태에 따른 개체목의 직경급별 본수, 수고, 재적과 임분의 평균흉고직경, 평균수고, ha당 본수 및 재적변화에 관한 생장을 예측할 수 있었다. 1개소의 잣나무 현실임분을 대상으로한 모델의 적용성 검토에 있어서, 간벌시나리오별 임분생장량을 비교한 결과, 간벌시업에 의한 임분밀도조절로 주벌시점의 재적량 증가효과를 기대할 수는 없는 것으로 나타났다. 그러나 간벌량과 주벌량을 포함하는 총수확량은 무간벌의 경우보다 간벌시업을 한 경우에 ha당 약 $40{\sim}75m^3$의 증가효과를, 그리고 임분의 평균흉고직경에서는 5 cm이내, 평균 수고에서는 1 m이내의 증가효과를 보였다. 본 연구를 통해 개발된 모델은 현실임분의 구성여건에 따라 간별의 실시 여부 및 간벌시업체계의 선택문제를 결정하는 의사결정지원도구로서 활용가능 할 것이다.

• The Korean Journal of Ecology
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• 제23권2호
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• pp.83-88
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• 2000

When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

• Journal of the Korean Wood Science and Technology
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• 제42권6호
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• pp.659-665
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• 2014

목재의 조직, 물리, 역학적 특성은 토양조건과 기후변화 등의 환경적 인자에 의해서도 바뀌게 됨으로 남부 세 지역의 임분 특성이 목재의 재질특성에 미치는 영향과 지역별 조직, 물리, 역학적 특성 등을 비교 검토하였다. 경상도, 전라도, 제주도의 졸참나무임지에 대해 임분 특성과 목재특성을 평가 분석하였는데 이들 간에는 대부분 높은 상관관계가 나타났다. 남부지역의 졸참나무는 온대에서 난대로 기후가 변화하는 난대 지역의 산림자원으로 본 목재재질특성 분석결과 유용한 산림자원으로 활용할 수 있을 것으로 생각된다.

• The Korean Journal of Ecology
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• 제24권6호
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• pp.341-348
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• 2001

Population dynamics of the oldest relic stand of Pinus densiflora for. erecta which remains as a status of patch in Sokwang-Ri area, Uljin-Gun, was studied to provide the basic data for conservation of the oldest pine stand in Korea. The upper slope site and ridge site including total 12 plots mainly represented Pinus densiflora for. erecta and Quercus mongolica. These two tree species showed reverse J-shaped distribution. From this information, it was concluded that intensive interspecific competition between two species could be occurring. Age distribution of P. densiflora for. erecta on the sites above middle slope area was indicated bi-modal type or tri-modal type which was known as an age structure of climax forest. Therefore, it was estimated that Pinus densiflora for. erecta population could be continuously maintained in the each patch above middle slope area. In the valley sites, hardwood species such as Q. mongolica, Q. variabilis, Styrax obassia and Acer pseudosieboldianum occupied most part of the under crown-cover area and their seedlings and saplings were developing into the closed upper layer crown because the height of upper layer crown reached about 35 meters and such a high crown height was more suitable for light utilization by plants of under layer. The growth patterns were mainly fluctuated for the entire life time of the oldest tree caused by frequent disturbance. And the initial growth curves of the mature trees and suppressed juvenile trees showed different tendencies along the sites.

• Journal of Animal Science and Technology
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• 제60권4호
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• pp.16.1-16.11
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• 2018

Background: In their first days of life, dairy calves in artificial rearing systems often have difficulty using an artificial teat for feeding. Methods: We examined the age at which calves are able to stand up voluntarily and suckle as well as their suckling behavior when presented with a plain dry teat versus a dry teat modified with a presumably attractive odor or taste substance. Single-housed newborn dairy calves (n = 51) were presented for ten consecutive days with a two-minute two-choice test, in which suckling time was recorded for 1) a plain (control) teat versus a glucose-coated teat (taste test) and 2) a plain teat versus a teat with a "Freshly Cut Grass" odor (odor test). Results: On average, the calves were able to stand up voluntarily and suckle from the second or third day of age on. The "Freshly Cut Grass" odor had no significant effect on their suckling behavior. In contrast, the calves showed a significant preference for suckling the glucose-coated teat and displayed a significantly longer total suckling time in the taste test compared to the odor test. There were no significant differences between sexes regarding suckling behavior. Conclusion: The results of the present study show that glucose had a significant effect on the calves' teat preference and significantly increased total suckling time with a dry artificial teat. As such, glucose may increase suckling motivation in non-efficient drinkers or ill calves with low motivation to suckle.

• International Journal of Automotive Technology
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• 제7권3호
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• pp.245-249
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• 2006

Accelerated aging of engine exhaust system components such as catalytic converters are traditionally performed using an engine/dynamometer test stand. $SwRI^{(R)}'s\;FOCAS^{(R)}$ system reduces or eliminates many of the engine based aging limitations. This paper will describe several studies. These include: 1) replication of engine based catalyst aging cycles with added precision and dependability; 2) catalyst aging with and without lubricating oil effects; 3) effects of lubricant phosphorus on catalyst performance; and 4) the potential to thermally age components beyond the capabilities of engine based systems. The first study includes the development of the SwRI FOCAS system to run programmed aging conditions with or without lubricating oil. A description of the subsystems is given. The second two studies used the SwRI FOCAS system to age catalysts. One study compared thermal-only aging using of the SwRI FOCAS system with equivalent aging on a traditional engine/dynamometer test stand. The other study examined the effect on catalyst performance of two lubricating oils containing different levels of phosphorus, and compared the results to field data generated using the same oils in a fleet of vehicles.

• 한국운동역학회지
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• 제32권3호
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• pp.87-93
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• 2022

Objective: The purpose of this research was to investigate the age-related changes in whole-body motor variability during sit-to-stand (STS) task. It has been reported that children perform motor tasks less accurately with greater variability as compared to adults. However, it is still unknown how they utilize the abundant degrees of freedom and accomplish voluntary actions. Uncontrolled manifold (UCM) analysis has been used to partition motor variabilities into two independent variability components, task-relevant variability (V_ORT) and task-irrelevant variability (V_UCM). We investigated what differences exist between children and adults with respect to these two motor variability components in relation to motor development stages. Method: Ten 6-year-old children (height: 116.2 ± 4.3 cm, weight: 23.1 ± 3.9 kg, motor development assessment percentile score: 77.5 ± 18.6%), ten 10-year-old children (height: 138.7 ± 7.2 cm, weight: 35.8 ± 10.3 kg, motor development assessment percentile score: 73.9 ± 12.7%), and ten young adults (age: 23 ± 1.6 year-old, height: 164.3 ± 11.4 cm, weight: 60.8 ± 12.0 kg) participated in this study. Each participant performed STS ten times, and a motion capture system was used to capture the whole-body kinematics. Each segment centers of mass and the whole-body center of mass were calculated, and UCM analysis was used to quantify motor variabilities, V_ORT and V_UCM. One-way ANOVA was used for statistical analysis. Results: We found that children produced more motor variabilities in V_ORT and V_UCM in all three dimensions, anterior-posterior, medial-lateral, and vertical. As age increased, both, V_ORT and V_UCM significantly decreased (p<.05). Conclusion: The greater V_ORT found in children compared to adults indicates that the repeatability over repetitions improves through development, while the greater V_UCM found in children suggests that children better utilize the abundant degrees of freedom during STS compared to adults.

• 신경치료
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• 제22권3호
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• pp.31-36
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• 2018

Purpose The purpose of this study was to investigate the effects of contact handorientation response(CHOR) during sit-to-stand(STS) in people with stroke. Methods The subjects of the study were Thirty hemiplegia participated (Rt. hemiplegia/Lt. hemiplegia: 15/15, mean age: $65.82{\pm}8.53$) in this study. The analysis of muscles activation (rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) distribution was conducted by the EMG, and the analysis of foot pressure distribution was conducted by the resistive pressure sensor. Hemiplegic stroke patients were instructed to perform STS three times with the non-affected side hand and affected side hand on the table. Results There was a significant positive correlation between rectus femoris, tibialis anterior muscle activation and affected side hand contact during STS(p<0.05). The STS correlated with the foot pressure in the affected side hand contact(p<0.05). Conclusion AS a result, CHOR during STS is related to muscle activation and the characteristics of foot pressure. This information was observed in the affected side hand contact on the table, suggestion that rehabilitation programs should be implemented.

• 한국산림과학회지
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• 제95권1호
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• pp.102-112
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• 2006

고도와 임령에 따른 임분 구조 변화를 알아보기 위하여 지리산 서부 지역의 해발 고도 약 400 m, 800 m, 1,000 m, 1,300 m 지역에 위치한 임분에서 $20m{\times}20m$ 방형구를 각각 3-8개씩 설치하고 흉고직경 2.5cm 이상인 임목을 대상으로 매목조사를 실시하였다. 소나무(Pinus densiflora Siebold & Zucc.)와 구상나무(Abies koreana Wilson)의 연령을 바탕으로 임령을 추정한 후 고도와 임령에 따른 수종 구성과 임분 구조를 분석하였다. 임분들은 고도에 따라 다른 수종 구성을 보였으며, 침엽수의 경우 고도 400 m 지역에서는 소나무가, 1,300 m 지역에서는 구상나무가 우점수종으로 나타났다. 참나무류는 낮은 지역의 굴참나무(Quercus variabilis Blume) 에서 고도가 높아짐에 따라 800 m 지역에서는 졸참나무(Quercus serrata Thunb. ex Murray), 1,000 m 이상에서는 신갈나무(Quercus mongolica Fisch. ex Ledeb.)로 우점수종이 변하였다. 직경분포는 고도에 따른 차이가 크지 않았으나, 임분의 상층 수고는 고도가 높아짐에 따라 낮아져, 1,000 m 이상에서는 수고 20 m 이상의 임목이 거의 나타나지 않았다(P<0.0001). 고도 400 m 지역의 소나무 우점 임분은 대략 30-40년과 70년생의 두 연령 그룹을 가졌으며, 고도 800 m 지역의 졸참나무 우점 임분의 임령은 약 30년인 것으로 추정되었다. 고도 1300 m에 지역에서 신갈나무 우점 임분은 상층 임목이 들어온 후 약 70년, 구상나무 우점 임분은 140년 이상된 것으로 추정되었으며, 직경분포는 임령에 따라 소나무에서 신갈나무, 신갈나무에서 구상나무로 우점종의 변화 가능성을 보여주었다.