• 지구물리
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• 제8권4호
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• pp.215-219
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• 2005

남극 웨델해 북부에 위치한 남스코시아해령을 가로지르는 측선에 대하여 다중채널 탄성파 탐사를 수행하였다. 남스코시아해령은 남극반도의 연장선에 존재하는 대륙지각으로 각각 해양지각인 스코시아해와 포웰분지와 접하고 있다. 남스코시아해령은 스코시아 판의 남쪽 가장자리를 이루고 있는 동-서 방향의 좌선 변환단층을 따라 횡장력에 의해 만들어졌다. 남스코시아해령 중앙에 위치한 중앙 함몰대는 경사부정합이 존재하며 남스코시아해령의 확장과정에 나타난 구조로 해석된다.

• 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.

• 한국농공학회논문집
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• 제61권4호
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• pp.43-54
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• 2019

The present study aims to monitor three of the community empowerment projects implemented as part of the community central revitalization projects in Yeongwol. We used an established indicator (i.e., quantitative evaluation) as well as an interview (i.e., qualitative evaluation) throughout the monitoring process. The PM (project manager) committee members, consisting of six interdisciplinary experts, carried out the monitoring from $24^{th}$ of October until the $26^{th}$ of November 2018. We categorized the results of the monitoring into the aspects of needs, software, and hardware, and analyzed them as follows: First, although the locals were willing to take part in programs, they were in overall not well informed about the ongoing programs and the program that suits their needs the most. The service organization should therefore actively publicize the program and provide sufficient information about it .Second, instead of a one-off program, the locals should be empowered to take over the program eventually and develop it as a local business model. Last, the locals from the center as well as the outskirts of Yeongwol should organize a learning net, collaboratively develop a further program, and assess its effectiveness by employing a thorough monitoring system.

• The Journal of Asian Finance, Economics and Business
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• 제9권7호
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• pp.205-217
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• 2022

The purpose of this study was to explore the relationship between agricultural insurance, agricultural loans, and the agricultural industry and find ways to consolidate and improve the interactive development between these three systems. We collected relevant data from 2009 to 2019 in 15 provinces of China and constructed a coupled coordination model to analyze the data. The results are as follows: First, the eastern part of China was ahead of the central and western parts in terms of agricultural loans and the agricultural industry, while the western part was ahead of the central and eastern parts in terms of agricultural insurance. Second, the coupling degree of the three systems in all 15 provinces reached an extremely high level. Third, all 15 provinces showed an overall continuous rise in coupling coordination degree. In 2019, eight provinces reached the medium-level coupling coordination development, and seven provinces were in a state of barely coupling coordination development. The three systems formed a mutually reinforcing relationship and basically entered a state of coordinated development. Finally, there was a great development gap between different regions of China concerning the coordinated development of the three systems, therefore, innovative development is urgently needed to further promote the coordinated development level.

• Structural Engineering and Mechanics
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• 제85권1호
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• pp.119-133
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• 2023

Impact event is the key factor influencing the operational state of the mechanical equipment. Additionally, nonlinear factors existing in the complex mechanical equipment which are currently attracting more and more attention. Therefore, this paper proposes a novel hybrid-separate identification strategy to solve the force identification problem of the nonlinear structure under impact excitation. The 'hybrid' means that the identification strategy contains both l1-norm (sparse) and l2-norm regularization methods. The 'separate' means that the nonlinear response part only generated by nonlinear force needs to be separated from measured response. First, the state-of-the-art two-step iterative shrinkage/thresholding (TwIST) algorithm and sparse representation with the cubic B-spline function are developed to solve established normalized sparse regularization model to identify the accurate impact force and accurate peak value of the nonlinear force. Then, the identified impact force is substituted into the nonlinear response separation equation to obtain the nonlinear response part. Finally, a reduced transfer equation is established and solved by the classical Tikhonove regularization method to obtain the wave profile (variation trend) of the nonlinear force. Numerical and experimental identification results demonstrate that the novel hybrid-separate strategy can accurately and efficiently obtain the nonlinear force and impact force for the nonlinear structure.

• Applied Microscopy
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• 제23권1호
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• pp.109-124
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• 1993

The prenatal development of thoracic spinal cord was studied by electron microscope in human embryos and fetuses ranging from 9mm to 260mm crown-rump length (5-30 weeks of gestational age). Ependymal cells in all fetal ages had conspicuous junctional complexes close to the lumen of the central canal into which microvilli and cilia projected. The ependymal cells contained numerous longitudinally arranged mitochondria, flattened cisternae of endoplasmic reticulum and Golgi complex. At 20 mm embryo, the floor and roof plates were composed of ependymoglial cells and undifferentiated neuroepithelial cells. The neuroepithelia of the sacral spinal cord were delineated from central medullary cord. By 100 mm fetus few undifferentiated neuroepithelial cells remained in the floor and roof plates. At 150 mm fetus, the whole central canal was formed by ciliated columnar epithelial cells containing cilia with basal bodies. The microvilli became tangled and club-shaped and formed a matted surface. The canal was filled with areas of dark and pale amorphous materials bounded by membrane-like structure. These two types of material were found throughout the whole central canal from 100 mm fetus onwards. By 260 mm fetus, microfibrils were first observed in the ependymal cells. In conclusion, it seems that early development and differentiation of central canal ependyma are simlar to that in other part of the brain ventricular system although ependymoglial cells are more prominent.

• Journal of Ecology and Environment
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• 제34권3호
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• pp.259-267
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• 2011

A pollen analytical study of sediment sequences collected from Yongneup moor (sampling point: $38^{\circ}$12'57.4" N, $120^{\circ}$7'30.2" E) was conducted to understand the vegetation history in the mountainous region of the central Korean peninsula. Carbon dating was carried out to measure five successive samples obtained from the bottom at a depth of 180 cm to the surface. The Yongneup moor sediment revealed four main local pollen zones; that is, four past vegetation phases as follows: Local pollen zone I: Quercus-Pinus zone; estimated age, 5,900-4,800 calibrated years (cal) before present (BP); vegetation type, cool-temperate central/montane deciduous broad-leaved forest. Local pollen zone II: Pinus-Abies-Quercus zone; estimated age, 4,800-3,400 cal BP; vegetation type, cool-temperate northern/alti-montane mixed coniferous and deciduous broad-leaved forest. Local pollen zone III: Quercus-Pinus-Abies zone; estimated age, 3,400-400 cal BP; vegetation type: cool-temperate central/montane deciduous broad-leaved forest. Local pollen zone IV: Pinus-Quercus zone; estimated age, 400-present cal BP; vegetation type, cool-temperate central/montane mixed deciduous broad-leaved and coniferous forest. It was confirmed that subalpine coniferous forests had expanded to the mountainous region of the central Korean peninsula during the period from 4,800-3,400 cal BP and thereafter deciduous forests dominated by Q. mongolica were established. Notably, secondary forests dominated by P. densiflora developed in the lower part of the mountainous region of the central Korean peninsula about 400 cal BP due to human interference.

• International Journal of Industrial Entomology and Biomaterials
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• 제2권2호
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• pp.173-180
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• 2001

The stink bug, Eocanthecona furcellata (Wolff.) is a natural and potential biocontrol agent of Spilarctia obliqua (Walk.). The present investigation reveals the biology, predatory efficiency and reproductive parameters of the predator which feeds on S. obliqua caterpillars in mulberry plantation. In order to find out the role of prey sine on the biology of the predators the predatory insects were separately fed with small and large caterpillars of S. obliqua. The incubation period of the eggs of E. furcellata was 8.37${\pm}$0.44 days, while the nymphal duration varied as per the prey sine. The predator when supplied with small larvae of prey, consumed 61.1 larvae and completed nymphal stage in 19.9 days; while those fed with larger prey, consumed 36.1 larvae and completed their nymphal stage in 21.55 days. The prey size also influences the reproductive parameters of the predator, The adult female predator is more voracious feeder than the adult male and consumed 41.9${\pm}$0.64 small larvae and 42.2${\pm}$0.87 large larvae during their life span. The longevity of male and female was observed as 20.7 and 29.4 days respectively. Visualization of the predator as well as the movement of the prey increases the predatory efficiency. Scanning electron microscopic studies on the feeding part explain its support in effective predation. Field observations indicated a drastic fall in the incidence of the mulberry pest, S. obliqua with the increased population E. furcellata in mulberry plantation.

• 한국광물학회지
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• 제22권4호
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• pp.279-288
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• 2009

경기만 표층퇴적물 시료 96정점에 대하여 고분해능 X선 회절분석기와 Siroquant v3.0 프로그램을 이용하여 광물조성을 구하였다. 연구해역 표층퇴적물은 조암광물이 대부분을 차지하며(석영 63.8%, 사장석 12.9%, 알카리장석 11.7%, 백운모 4.3%, 각섬석 1.2%, 흑운모 0.5%), 점토광물(일라이트 2.4%, 녹니석 1.4%, 카올리나이트 0.4%) 및 소량의 탄산염광물(방해석 0.1%, 아라고나이트 0.3%)로 구성되어 있다. 조립질 퇴적물은 연구해역 북쪽, 남쪽과 중앙부에서 많이 분포하며, 세립질 퇴적물은 연구해역 중앙부 북쪽과 남쪽에 동서 방향으로 긴 형태의 분포를 보인다. 연구해역의 남쪽에는 석영의 함량이 상대적으로 높은 조립질 퇴적물이 퇴적되고, 연구해역 북쪽에서는 사장석, 백운모, 각섬석 등의 함량이 높은 조립질 퇴적물이 퇴적되는 것으로 나타난다. 연구해역 중앙부의 남쪽에는 일라이트의 함량이 상대적으로 높은 세립질 퇴적물이 퇴적되고, 연구해역 중앙부의 북쪽에서는 녹니석과 카올리나이트의 함량이 상대적으로 높은 세립질 퇴적물이 퇴적되는 것으로 나타난다.

• Ocean and Polar Research
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• 제34권2호
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• pp.111-123
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• 2012

To understand the phytoplankton community in the eastern part of the Yellow Sea (EYS), in the summer, field survey was conducted at 25 stations in June 2009, and water samples were analyzed using a epifluorescence microscopy, flow cytometry and HPLC method. The EYS could be divided into four areas by a cluster analysis, using phytoplankton group abundances: coastal mixing area, Anma-do area, transition water, and the central Yellow Sea. In the coastal mixing area, water column was well mixed vertically, and phytoplankton was dominated by diatoms, chrysophytes, dinoflagellates and nanoflagellates, showing high abundance ($>10^5\;cells\;l^{-1}$). In Anma-do coastal waters characterized by high dominance of dinoflagellates, high phytoplankton abundance and biomass separated from other coastal mixing area. The southeastern upwelling area was expanded from Jin-do to Heuksan-do, by a tidal mixing and coastal upwelling in the southern area of Manjae-do, and phytoplankton was dominated by benthic diatoms, nanoflagellates and Synechococcus group in this area. Phytoplankton abundance and biomass dominated by pico- and nanophytoplankton were low values in the transition waters and the central Yellow Sea. In the surface of the central Yellow Sea, high dominance of photosynthetic pigments, 19'-hexanoyloxyfucoxanthin and zeaxanthin implies that haptophytes and cyanobacteria could be the dominant group during the summer. These results indicate that the phytoplankton communities in the EYS were significantly affected by the formation of tidal front, thermal stratification, and coastal upwelling showing the differences of physical and chemical characteristics during the summer.