Earticle

Tap root and lateral root systems of trees have long been recognized for enhancing slope stability by reinforcing soil strength. Among these, the lateral root system is particularly effective in preventing shallow landslides. In South Korea, where forest soils are relatively shallow, the role of tree roots in stabilizing slopes is becoming increasingly important. This study aimed to evaluate the root cohesion of four major tree species in South Korea: Pinus densiflora, Pinus koraiensis, Larix kaempferi, and Quercus mongolica. To achieve this, we investigated the spatial distribution of their lateral root systems using the profile wall method in an experimental forest at Kangwon National University. In addition, the relationship between root diameter and tensile strength was assessed in the laboratory using a universal testing machine. Based on the findings, root cohesion was estimated using the Wu model. For all species, the number of roots and root area ratio decreased with increasing soil depth, although the extent of decrease varied by tree species. A power-law regression model effectively described the relationship between root diameter and tensile strength in all species. The average root tensile strength was higher in Q. mongolica (22.2 MPa) and L. kaempferi (20.2 MPa) than in P. densiflora (15.9 MPa) and P. koraiensis (15.0 MPa). Root cohesion estimated using the Wu model was 1.5 to 5.1 times higher than that measured by the direct shear test. After applying a reduction coefficient, root cohesion estimated by the Wu model was highest in Q. mongolica (12.9 kPa), which exhibited the greatest root area ratio and tensile strength, followed by P. koraiensis (9.1 kPa), P. densiflora (9.0 kPa), and L. kaempferi (4.3 kPa). These results provide useful information for quantifying the role of tree roots in preventing shallow landslides and can support the establishment of forest disaster management strategies.

To examine the soil reinforcement by the shrub with shallow root systems for slope stability, we developed insitu apparatus for direct shear test and conducted the insitu field tests for Lespedeza cyrtobotrya, a representative revegetation species for artificial hillslopes. The insitu field tests were conducted for two different soil conditions (the rooted soils and non-rooted soils) and we then compared the experimental values with those calculated from the Wu model. The results showed that the soil reinforcement derived from the insitu field tests ranged from 0.01525 to 0.1438 kgf/cm2 while the one calculated from the Wu model ranged from 0.1952 to 0.2696 kgf/cm2 . Our finding suggests more field tests are needed to collect the related parameters in the model application thereby predicting the reliable soil reinforcement by the shrub root systems.

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

Cancer-preventive effects of ethanol extract of elm tree root (EEE) were investigated. In the in vitro cytotoxicity assay, colon cancer cells were incubated with a chloroform fraction of EEE (CF-EEE). CF-EEE significantly inhibited the proliferation of cells and induced apoptotic cell death in a dose-dependent manner. For the assessment of chemopreventive efficacy in vivo, male F344 rats were fed with EEE (0.5 or 1%) in diet for 8 weeks, and were subcutaneously injected with 1,2-dimethylhydrazine (DMH) to induce colonic aberrant crypt foci (ACF). EEE (0.5 and 1%) significantly decreased both the numbers of AC (1191.1/colon) and ACF (529.3/colon) induced by DMH. In addition, in the Western blot analysis on the colonic mucosa, administration of EEE triggered expression of caspase-3, a key factor of an apoptotic cascade. These results suggest that extract of elm tree root may have potential chemopreventive principles that lead to apoptosis of cancer cells, and thereby suppress colorectal carcinogenesis during the initiation stage.

This study was carried out to find the suitable root-ball size for the planting construction of landscape trees. Surveyed trees for this study were Cercidiphyllum japonicum and Prunus yedoensis, and the root-ball size was classified into 3D, 4D, 5D, and 6D(D meaning the diameter at the base of a tree). Visual ratings on a scale of 1 to 9 were used as a means for measuring the regrowth strength after planting tested trees. Test trees with 3, 4, 5 and 6D root-ball size were planted on March. 16, 2002 and visual ratings were measured up to April. 30, 2003. Cercidiphyllum japonicum and Prunus yedoensis started showing a difference in regrowth by each rootball size a month after planting. The regrowth quality of Cercidiphyllum japonicum was low at 3D, medium at 4∼5D and high at 6D root-ball size, while the regrowth quality of Prunus yedoensis was low at 3∼4D and medium-high at 5∼6D root-ball size. According to the above results, a root-ball size for good regrowth quality was a little bit different between Cercidiphyllum japonicum and Prunus yedoensis. 4D of Cercidiphyllum japonicum and 5D of Prunus yedoensis could be guidelines for root-ball diameters at the base of trees when planting. However, we concluded that 4D∼5D root-ball is the optimum guideline for regrowth when adapting this guideline to all landscape trees with 8∼l0cm diameter at the base.

본 연구의 목적은 갤럭시노트7의 예를 들어 신제품의 실패를 시스템 안전분석 기법을 활용해 체계적으로 분석하는 것이다. 이러한 분석을 통해 제품실패의 근본적인 원인을 찾고 그 원인으로 발생하는 문제를 해결함으로써 사건재발을 방지하는데 도움이 되는 정보를 제공하고자 한다. 이를 위해 제품실패를 단순히 기술적 실패로 바라보는 것이 아니라 제품개발과 경영관리가 포함된 하나의 통합 시스템으로 바라보며, 그에 대한 실패의 근본적인 원인들을 분석할 필요가 있다. 이러한 관점을 갖고 시스템 안전분석 기법인 근본원인분석과 고장수목분석을 활용해 갤럭시노트7의 제품실패 원인을 분석하였다. 이러한 분석과정을 통해 배터리 과열이라는 피상적인 기술적 문제와 더불어 경쟁사와의 지나친 경쟁에 따른 무리한 제품출시와 성과주의와 같은 제품개발 및 경영관리에서의 문제에도 많은 관심을 기울일 필요가 있음을 파악하였다. 또한 통합 시스템적 관점을 견지한다면 제품실패의 원인을 분석하는데 근본원인분석과 고장수목분석이 유용하게 이용될 수 있음을 확인할 수 있었다.

This study aims to analyze the causes of a new product failure by using system safety methods, focusing on the case of Samsung Galaxy Note7. However, when analyzing the causes of a product failure, if only technical problems are too emphasized, it is likely to miss other more meaningful causes of a failure. Thus, we claim that the root causes of a product failure should be identified in a broad perspective of integrated systems that include non-technical as well as technical elements. With this viewpoint, we investigated the failure of Samsung Galaxy Note7, by using Root Cause Analysis(RCA) and Fault Tree Analysis (FTA). The results showed that it is necessary to address not only the technical issues but also other non-technical issues, such as a very impetuous launch of a new product due to a very tough competition in the market. Additionally, we also found that RCA and FTA could be a useful tool for analyzing the causes of a new product failure from the viewpoint of an integrated system comprising technical and management elements.

The trees are of great meaning to the life and daily life of the human beings in various fields. However, the trees would disturb the normal activities of peoples. One of the problems is the growth of the tree roots close to the buildings or the roads can cause directly or indirectly structural damages. In this paper, a electrical measurement method based on resistivity is proposed The electrical property of tree root is analyzed. Finally, a tree root measurement system is built and practically tested.

본 연구에서는 건조된 녹차 뿌리와 씨에 함유된 성분중에서 무기성분, 비타민, 총 아미노산과 유리 아미노산, 총 폴리페놀 및 그 구성 성분들의 함량을 분석하였다. 뿌리와 씨의 무기성분 중에서는 K의 함량이 각각 1,052 ㎎/100 g과 1,480 ㎎/100 g으로 가장 많았고, 뿌리에서 P, Ca, Mg, Na, Fe, Mn, Zn, Cu의 순으로, 씨에서는 P, Na, Ca, Mg, Mn, Fe, Cu, Zn의 순으로 함량이 많았다. 뿌리에서 vitamin C의 함량은 5.72 ㎎/100 g으로 가장 많았고 씨에서는 6.05 ㎎/100 g으로 나타났다. 비타민의 함량을 살펴 본 결과 녹차 뿌리보다 씨에 더욱 많은 종류의 vitamin이 함유되어 있었고 그 함량도 뿌리에 비해 다소 높은 경향이었다. 총 아미노산은 뿌리에 1,651 ㎎/100 g, 씨에 4,335 ㎎/100 g 함유되어 있어 각국 시판 녹차에 비해 그 함량이 높았고, 녹차에서 존재하지 않는 아미노산인 phenylalanine도 16.00 ㎎/100 g와 139.00 ㎎/100 g 존재하는 것으로 나타났다. 유리 아미노산의 경우, 뿌리에서 녹차의 품질을 평가하는 theanine이 전체 유리아미노산 함량의 48%를 차지하였고 쓴맛을 내는 arginine, valine 및 tryptophan 등의 함량이 높았으며, 열매에서는 단맛과 감칠맛을 내는 glutamic acid, alanine, theanine, aspartic acid 및 serine 등의 함량이 많았다. 총 polyphenol은 뿌리에 237 ㎎/100 g으로 씨에서의 함량 81 ㎎/100 g보다 3배가량 높았다. Polyphenol 중 catechin의 함량은 뿌리에서 66 ㎎/100 g, 씨에서 1 ㎎/100 g으로 나타났고 caffeic acid는 뿌리에서 0.78 ㎎/100 g으로 나타났지만 씨에서는 검출되지 않았다. 또한 chlorogenic acid는 뿌리와 씨에서 각각 3.7 ㎎/100 g과 6.6 ㎎/100 g 검출되었다.

Green tea is popular plants in Asian countries and has become more widespread in western countries due to its taste characteristics and health benefits. Apart from green tea leafs, however, the use of root and seed of green tea tree has not intensively been investigated yet. In this study, the contents of mineral, vitamin, total amino acid, free amino acid, and total polyphenol (catechin, caffeic acid, and chlorogenic acid) of the root and seed of green tea tree were analyzed for the development of healthy foods. For minerals, potassium contents were 1,052 and 1,480 mg/100g-dry weight of root and seed, respectively. The order of mineral contents were as follows: K > P > Ca > Mg > Na > Fe > Mn > Zn > Cu in root and K >P > Na > Ca > Mg > Mn > Fe > Cu > Zn in seed. For vitamins, vitamin C contents were 5.72 and 6.05 mg/100g-dry weight of root and seed, respectively. The presence of more various kinds of vitamins were observed in seed than in root. For total amino acids, the contents were 1,651 and 4,335 mg/100g-dry weight of root and seed, respectively. The total amino acid contents of seed and root were higher than those in commercial green tea products. Especially the phenylalanine contents were 16 and 139 mg/100g-dry weight of root and seed, respectively whereas phenylalanine was not found in commercial green tea products. Concerning free amino acids, the bitter tasting amino acids such as arginine, valine and tryptophan were more abundant in root and the sweet tasting ones such as glutamic acid, alanine, aspartic acid, and serine were more abundant in seed. The total polyphenol contents were 237 and 81 mg/100g-dry weight of root and seed, respectively. The polyphenol contents in root were three times higher than that in seed so root may be a better source for antioxidant ingredients than seed. Among many polyphenols, catechin, caffeic acid, and chlorogenic acid were the top three major components.

Background: In ecosystem carbon cycle studies, distinguishing between $CO_2$ emitted by roots and by microbes remains very difficult because it is mixed before being released into the atmosphere. Currently, no method for quantifying root and microbial respiration is effective. Therefore, this study investigated the relationship between soil respiration and underground root biomass at varying distances from the tree and tested possibilities for measuring root and microbial respiration. Methods: Soil respiration was measured by the closed chamber method, in which acrylic collars were placed at regular intervals from the tree base. Measurements were made irregularly during one season, including high temperatures in summer and low temperatures in autumn; the soil's temperature and moisture content were also collected. After measurements, roots of each plot were collected, and their dry matter biomass measured to analyze relationships between root biomass and soil respiration. Results: Apart from root biomass, which affects soil's temperature and moisture, no other factors affecting soil respiration showed significant differences between measuring points. At each point, soil respiration showed clear seasonal variations and high exponential correlation with increasing soil temperatures. The root biomass decreased exponentially with increasing distance from the tree. The rate of soil respiration was also highly correlated exponentially with root biomass. Based on these results, the average rate of root respiration in the soil was estimated to be 34.4% (26.6~43.1%). Conclusions: In this study, attempts were made to differentiate the root respiration rate by analyzing the distribution of root biomass and resulting changes in soil respiration. As distance from the tree increased, root biomass and soil respiration values were shown to strongly decrease exponentially. Root biomass increased logarithmically with increases in soil respiration. In addition, soil respiration and underground root biomass were logarithmically related; the calculated root-breathing rate was around 44%. This study method is applicable for determining root and microbial respiration in forest ecosystem carbon cycle research. However, more data should be collected on the distribution of root biomass and the correlated soil respiration.

본 연구에서는 유역단위 토사발생 모의의 주요 인자인 식생뿌리의 깊이에 대한 정량화를 시도하였다. 본 연구에 사용된 자료는 2006년 7, 8월 집중호우로 발생한 강원도 산사태 피해지역의 사면파괴지역에서 측정한 것이다. 조사된 자료를 이용하여 사면경사와 뿌리깊이와의 관계를 확률밀도함수를 이용하여 정량화하였다. 본 연구에서는 뿌리깊이를 중력방향과 사면수직방향에 대해 각각 고려하였다. 마지막으로, 결정된 확률밀도함수를 이용하여 뿌리깊이를 모의하기 위한 방법을 제시하였다. 그 결과 뿌리깊이에 대한 적절한 확률밀도함수로 2변수 감마분포가 선정되었으며, 선정된 분포는 원자료의 특성을 잘 나타내고 있는 것으로 확인되었다. 그러나 뿌리깊이를 중력방향 또는 사면수직방향으로 정량화 하느냐는 특히 관측자료의 개수 및 기타 지형적 상황을 고려하여 적절히 선택할 수 있을 것으로 판단된다. 이러한 결과는 추후 유사지역의 유역단위 토사발생 모의에 있어 필요한 뿌리깊이의 추정에 적절히 이용될 수 있을 것이다.

This study quantified the tree root depth, an important factor in the simulation of basin-scale sediment yield. The data used in this study were those measured in the area of landslide due to heavy rainfall around July and August, 2006. These field survey data was quantified the relationship between slope and tree root depth using a probability density function (pdf). The tree root depth in this study considers both the gravitational direction and perpendicular direction to the plane. Finally, a methodology to generate tree root depth data using the pdf decided. As results, the two parameter gamma distribution was selected and found to well represent the tree root depth data. However, one should consider the number of data available or other geomorphological conditions to decide if the quantification of tree root depth is with respect to the gravitational direction or perpendicular direction to the plane. The results in this study may be used effectively for the estimation of tree root depth in the basin-scale sediment yield.

The objective of this study is to investigate and evaluate that a roadside tree root intrudes sewer network systems. Two approaches were performed to assess the characteristics of tree root intrusion. First, the characteristics of tree roots that had invaded sewers were directly observed by means of closed-circuit television inspection robot. Second, the intrusion proportions of tree root into rain gutters in the sampling area were investigated. As tree species of low intrusion proportions, the results indicated that Ginkgo biloba Linn. and Acer buergerianum Miq. were 1.7% and 4.3%. On the other hand, tree species of high intrusion proportions were Metasequoia glyptostroboides Hu et Cheng, Ulmus davidiana var. japonica Nakai and Zelkova serrata Makino as 22.2%, 20.4%, and 17.6% respectively. In particular, sewers and gutters around Zelkova species should be the focus of maintenance work because of the high proportion of these trees on roadsides.

본고는 박상륭의 「두 집 사이」 連作에 나타난 主體의 存在論的 사유를 고찰하고자 하였다. 「두 집 사이」 連作은 ‘中陰 여행’ 중인 주인공의 시간적 思惟를 통하여 實存性을 回復하고자 하는 反省 主體의 認識을 보여준다. 끝없이 이어지는 주인공의 의식은 반성적 자아와 반성되는 自我와의 존재적 極點을 통해 疏外를 극복하고자 하지만, 결국 시간적 有限性, 즉 죽음의 존재양식을 통해 시간의 本來性에 直面한다. 이때 죽음이란 가장 절박한 存在樣式이다. ‘늙은네’는 시간의 유한성을 상징하는 죽음을 통해 불안이라는 존재론적 思惟에 직면한다. 불안은 자신이 죽음에 직면한 存在者라는 것과 동시에 現存在로서의 자신을 直視하게 되는 동인으로 작용한다. 이처럼 『잠의 열매를 매단 나무는 뿌리로 꿈을 꾼다』에 수록된 「두 집 사이」연작은 늙은네의 존재론적 사유를 통하여 타자 의식으로서의 反省 主體의 모습을 형상화하고 있다.

This paper attempts to study the subject of ontological thought which appears in Park Sang-ryung's serial novel between two existence. The consciousness of a reflective subject that tries to recover existence is shown through the temporal thoughts of a hero who is ‘Bardo (antar?bhava)’. Through the existential extreme of a reflecting and reflective self, the consciousness of the hero, who is conscious of his endless existential thoughts, tries to overcome estrangement but, in the end, through temporal limitations, namely, the mode of existence called death, the essential nature of time is confronted. This time death is called the most urgent mode of existence. Through death, which symbolizes the limitation of time, “the aged you” confronts the existential thought called anxiety. This time anxiety makes us conscious that the one who is called the existent one is facing death and, at the same time, acting as an agent that makes him face himself as a present being. Through the existential thought of “the aged you,” the serial novel between two existence creates the form of its reflective subject as the consciousness of the other like this. Based on the will to endlessly overcome the self, ‘the creation of the universe of the heart’, Park Sang- nyung's highest literary achievement, escapes collectivity and shows what is called sincerity through creation as complete individualism.

본 시험은 5~6월 수분스트레스가 사과나무의 광합성, 신초생장 및 과실품질에 미치는 영향을 구명하고자 실시하였다. 단근은 만개기(4월 30일)에 원줄기에서 30cm와 60cm 떨어진 곳에서 열 방향에 따라 양쪽 혹은 한쪽으로 처리 하였다. 무처리구의 5~6월 오후 평균 잎수분포텐셜은 -1.80MPa 이상을 유지하였지만, 단근 처리구들은 -1.80MPa 이하였다. 단근 처리 정도에 따른 5~6월경 오후 평균 잎 수분포텐셜은 양쪽 30cm 단근구(-2.06MPa), 양쪽 60cm 단근구(-2.02MPa), 한쪽 30cm 단근구(-1.91MPa) 순으로 낮았다. 한쪽 30cm 단근 처리와 양쪽 30cm 단근 처리는 5~6월 광합성속도를 각각 무처리구의 80% 및 65% 수준으로 감소시켰다. 또한, 한쪽 30cm 단근구의 무처리구 대비 총 신초장과 평균 과중의 감소 정도는 각각 25% 및 11% 정도였던 반면에 양쪽 30cm 단근구는 각각 45% 및 15% 정도였다. 그러나 가용성 고형물 함량 및 착색 정도는 단근 처리구들이 무처리구보다 높았으며, 양쪽 단근구들이 한쪽 단근구보다 더 높았다. 결론적으로, 5~6월 오후 평균 잎 수분포텐셜이 -1.80MPa 이하이면 과실비대가 감소되었고, -2.00MPa 이하이면 신초생장이 감소되었다.

This study was conducted to find out the influence of water stress from May to June on photosynthesis, shoot growth and fruit quality of apple trees. Fuji'/M.9 apple trees were root pruned at full bloom (30th April), parallel to the row of 30 cm or 60 cm from the trunk, to one side or both sides of trunk. The average value of afternoon leaf water potential from May to June of the no root pruning was maintained over -1.80 MPa, but that of root-pruning treatments was maintained under -1.80 MPa. In the comparison of average value of leaf water potential from May to June by root-pruning degree, the root pruning both sides at 30 cm from trunk was lowest (-2.06 MPa), followed by the root pruning both sides at 60 cm (-2.02 MPa) and the root pruning one side at 30 cm (-1.91 MPa). Root pruning one side at 30 cm or both sides at 60 cm reduced photosynthetic rate from May to June by 80% or 65%, respectively, compared with no root pruning. So, the degree of decreasing total shoot length or average fruit weight compare to the no root pruning of the root pruning one side at 30 cm was 25% or 11%, respectively, and those of the root pruning both sides at 30 cm was 45% or 15%, respectively. However, the soluble solid content and fruit color of the root pruning was higher than those of the no root pruning, and those of the root pruning both sides was higher than root pruning one side. These results indicate that the fruit enlargement was decreased when the average value of average leaf water potential from May to June was under -1.80 MPa, and the shoot growth was decreased when that was under -2.00 MPa.

In this paper, we studied what the drug name of Sang-Baik-Pi(桑白皮) Mori Cortex Radicis) is, how to collect it; and how the chief symptoms had changed in the chinese medical references and herbological literatures and formularies. Also we bibliographically analyzed in the herbological way the drugs combinated with Sang-Baik-Pi and their active principles among the prescriptions in the famous medical book; 'Dong-Ui-Bo-Gam', (東醫寶鑑) of our country. Finally, we concluded as foolow. Numerous names of botainical origin were described, but it was not recorded that San-Keun-Baik-Pi(桑根白皮) in old days is different from root bark of Morus sp. in this times. Sang-Baik-Pi has been a common designation since Ming dynasty (AD 1500). Collections of it were independent of seasons, it could effect perfectly over 10 years old. And its cork layer should be removed after collections, it was especially emphacised that root bark on ground was poisonous. The chiefly cured symptoms with Sang-Baik-Pi were constantly not different from the contents of 'Shin-Nong-Bon-Chau-Kyung'(神農本草經) in ancient times, but it has been developed since Ming dynasty. Its uses are widely extended to a surgical and dermatologic desease; rheumatis, beriberi and diabetes in this times. and its efficacies depend upon curing. Prescriptions on Sang-Baik-Pi that were prescribed in 'Dong-Ui-Bo-Gam' are there, 177 drugs combinated with it. Glycyrrhizae Radix is most frequently combinated with Sang-Baik-Pi(frequently 68%). It is proved that Armeniacae Semen, Platycodi Radix etc, in the order take strong effects on anti-tussive, anti-phlogistic, diuretic, anti-pyretic etc. It is expressed 34 times, frequently, that a dose is 3.75g, and it shows that a usual doses is 2-4g. As the above prescriptions are classified, the results is as follows, respiratory tract desease is most frequently in 69 prescriptions, the next gastrointestinal tract 13 times, diuretic 12 times, and antipyretic 11 times. Therefore, Sang-Baik-Pi contains a good remedial value chiefly of the effects upon the respiratory diseases.