• Communications for Statistical Applications and Methods
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• 제11권2호
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• pp.323-327
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• 2004

In this paper, we investigate the limiting distribution of the Ljung-Box test statistic in the unit root AR models with ARCH errors. We show that the limiting distribution is approximately chi-square distribution with the degrees of freedom only depending on the number of autocorrelation lags appearing in the test. Some simulation results are provided for illustration.

• Journal of Periodontal and Implant Science
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• 제32권1호
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• pp.61-68
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• 2002

The objective of this study was to determine the incidence and distribution of root fusion as well as its sexlinkage in maxillary and mandibular molars. One hundred fifty patients who had eight maxillary and mandibular molars (third molars excluded) were consecutively selected for the study subjects. The subjects provided a total of 1200 molars, i.e., 600 maxillary and 600 mandibular molars. A decision about root fusion was made on the radiographic examination. If a molar had one root and/or roots fused at any part in the root surface, it was considered as having root fusion. The results showed that : (1) 14.1 % of the maxillary molars and 5.8 % of the mandibular molars had a fused root, (2) the prevalence of root fusion in the male was 33 % and 56.4 % in the female, (3) 60 % in the male and 48.8 % in the female had bilaterally paired root fusion, (4) the root fusion was most frequently observed in the maxillary second molar position, but none in the mandibular first position in this study. Within limitations of this study, it can be concluded that, in management of molars with a furcation problem, treatment options such as hemisection and root amputation should be chosen after careful evaluation of root fusion. Further studies are needed to investigate a possible relationship between root fusion and periodontal disease progression.

• Imaging Science in Dentistry
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• 제36권3호
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• pp.137-143
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• 2006

Purpose : To evaluate location, distribution, diameter, and length of the nutrient canals on mandibular anterior region using a cone beam computed tomography (CBCT). Materials and Methods : Mandibular CBCT was performed on 33 adults (18 males and 15 females) with no history of systemic disease, and any other dental surgery history Location, distribution, diameter, and length of the nutrient canals on mandibular anterior region were radiographically evaluated. A statistical comparison was done by SPSS. Results : In the location and distribution of nutrient canals, they were found in 6.8% at labial portion above root apex, in 93.28% at lingual portion above root apex in 46.2% at labial portion below root apex, and in 53.6% at lingual portion below root apex. Nutrient canals at lingual portion above root apex were most frequently observed between central and lateral incisors, and those at labial and lingual portion below root apex were most frequently observed between central incisors. The mean diameters of nutrient canals were 0.54 mm at labial portion above root apex, 0.61 mm at lingual portion above root apex, 0.66 mm at labial portion below root apex, and 0.76 mm at lingual portion below root apex. The mean lengths of nutrient canals were 2.63 mm at labial portion above root apex, 3.74 mm at lingual portion above root apex, 4.51 mm at labial portion below root apex, and 6.77 mm at lingual portion below root apex. Conclusion : CBCT is useful device to evaluate the anatomical structure of nutrient canals on mandibular anterior region.

• Journal of Plant Biology
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• 제20권1호
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• pp.15-22
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• 1977

As a basic research for the yield-mechanism of soybean seeldings, the distribution and variety of free amino acid and protein-amino acid in some parts of root were studied. At the meristematic, elongational and maturated zones of root, the distribution and variety of N-components was different substantially. It shows that N-components are taken part in energy source for organization in early stage of growth. N-pool also changed in every part of root.

• Journal of Ginseng Research
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• 제4권1호
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• pp.55-64
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• 1980

The distribution pattern of mineral nutrients, among various Parts of Korea ginseng (Panax ginseng C.A. Meyer) was investigated to understand ginseng nutrition by simple correlation analysis. Five·year old ginseng plants grown under four different nutritional environments were sampled and separated into leaf, petiole, stem, rhizome, cortex and epidermis of tap foot, central part of tap root, cortex and epidermis of lateral root, central part of lateral root, fine root in the middle of truly, for chemical analysis. Between mineral nutrients in root, N and P showed highly significant positive correlation each other and with Mg and Cu while all other elements (K, Ca, Mg, Fe, Mn, Zn, Cu, B) showed highly significant positive correlation each other. In shoot, number of mineral nutrient pairs haying significant relation was much less than in root. (Negative: P with Ca or B, K with N, Fe, Mn or Cu, Positive: N with Mg, Fe, Mn or Cu, K with Zn, Ca with Mg, Zn, or B, Fe Mn Cu each other, Mn with B.) The number of pairs having significant correlation in whole plant was approximately the same as the number in root but three of them showed significant negative correlation. The distribution pattern similarity of mineral contents among various parts was also discussed in relation to physiological significance in Korea ginseng plant.

• 한국작물학회지
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• 제51권4호
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• pp.295-297
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• 2006

Potassium (K) distribution in rice (Oryza sativa L.) root was studied by confocal laser microscopy, using potassium sensitive fluorescent dye potassium-binding benzofuran isophthalate (PBFI). Significantly high intensity of K-specific fluorescence was detected at the root cap region followed by meristematic and basal regions. A negligible or fainted fluorescence was observed at the root hairs area. These results suggest that K is heavily distributed in the apical area of rice root, which may be required in higher concentration for division and extension of cells, as it is the rapidly growing region of the root, moreover, may also be involved in water uptake by creating osmotic gradient across membranes.

• The Plant Pathology Journal
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• 제39권6호
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• pp.575-583
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• 2023

Fusarium root rot is an increasingly severe problem in soybean cultivation. Although several Fusarium species have been reported to infect soybean roots in Heilongjiang province, their frequency and aggressiveness have not been systematically quantified in the region. This study aimed to investigate the diversity and distribution of Fusarium species that cause soybean root rot in Heilongjiang province over two years. A total of 485 isolates belonging to nine Fusarium species were identified, with F. oxysporum and F. solani being the most prevalent. Pot experiments were conducted to examine the relative aggressiveness of different Fusarium species on soybean roots, revealing that F. oxysporum and F. solani were the most aggressive pathogens, causing the most severe root rot symptoms. The study also assessed the susceptibility of different soybean cultivars to Fusarium root rot caused by F. oxysporum and F. solani. The results indicated that the soybean cultivar DN51 exhibited the most resistance to both pathogens, indicating that it may possess genetic traits that make it less susceptible to Fusarium root rot. These findings provide valuable insights into the diversity and distribution of Fusarium species that cause soybean root rot and could facilitate the development of effective management strategies for this disease.

• 한국환경복원기술학회지
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• 제14권4호
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• pp.41-54
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• 2011

Tree roots can enhance soil shear strength and slope stability. However, there has been a limited study about root reinforcement of major tree species in Korea because of some experimental difficulties. Thus, this study was conducted to analyze the performance of Japanese larch (Larix kaempferi) and Korean pine (Pinus koraiensis) which are two common plantation species in Korea. Profile wall method was used to measure the spatial distribution of root system and its diameter within 15 soil walls of Japanese larch stand and 13 soil walls of Korean pine stand in Taehwa University Forest, Seoul National University, Korea. Root tensile properties of each species were assessed in the laboratory, and root reinforcements were estimated by Wu model. The study observed that the number and cross-sectional area (CSA) of root in both species could tend to decrease with soil depth. Especially, CSA were well-fitted to exponential functions of soil depth. Mean root area ratios (RAR) were 0.03% and 0.10% for Japanese larch and Korean pine, respectively. Estimated root reinforcement from Wu model were, on the average, 4.04 kPa for Japanese larch and 12.26 kPa for Korean pine. Overall, it was concluded that root reinforcement increased the factor of safety (Fs) of slope for small-scale landslide as the result of two-dimensional (2-D) infinite slope stability analysis considering vegetation effects.

• 대한조선학회지
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• 제20권4호
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• pp.17-24
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• 1983

In this study, it was investigated the distribution of residual stress in the direction of loading between the root and toe the load fillet welds for thick steel plate. Residual stress distributions are measured by sectioning method which is one of stress-relaxation technique in welded joint, and analyzed by two dimensional finite element method on thermo-elasto-plastic theory under plane stress condition. These are compared the results of F.E.M analysis with the experimental result by stress-relaxation techniques. As a results, the following conclusion were obtained. (1) In the no penetration fillet welded joint specimen using mild steel plate with 25mm in thickness, the residual stress of loading direction near the root was about $10kg/mm^2$ tensile. (2) The tensile residual stress has been observed in fillet region of the fillet joint by F.E.M. analysis method. (3) The range of compressive residual stress distribution from the root was largest in the case of 5mm root penetration.

• Journal of Ginseng Research
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• 제11권1호
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• pp.10-16
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• 1987

인삼제품의 품질관리와 효능연구의 시료사용에 참고자료로 활용하기 위하여 인삼근의 부위별, 연근별 사포닌 함량 및 분포를 조사하였다. 한국인삼 6년근의 부위별 조성은 뇌두(rhizome) 4.1%, 동체(main root) 47.7%, 지근(lateral)의 비는 대략 1:1이었으나 지근부는 2:1로 피층이 많았다. 사포닌분포는 동체와 세근부가 29% 정도로 거의 같고, 지근부 34.6%로 가장 많았고, 뇌두는 7% 수준으로 가장 적었다. 그러나 단위 중량당 함량에서는 세근>퇴두>지근>동체의 순으로 뇌두가 높은 반면 동체는 가장 낮았다. 연근별 사포닌 변화는 2년근 4.89%, 6년근 7.98%로서 본포이식후 4년간 약 3% 증가에 그쳤으나 뿌리의 비대성장을 고려할 때 계속적으로 합성축적 되었으며 연간 증가율은 5년근이 43.8%로 가장 왕성한 성장기임을 나타내고 4년근 19.8%, 6년근 21.1%로 비슷했다. 따라서 5년에 뿌리의 생장과 사포닌 합성축적이 최고 수준에 도달했다가 6년째 부터 쇠퇴기로 됨을 알았다. 개별 사포닌의 함량변화는 전반적으로 증가하는 경향이나 PT계 사포닌보다는 PD계 사포닌의 증가가 보다 큰 경향이었다.