Wyniki wyszukiwania - Biblioteka Nauki

1

Performance analysis of doppler aided GPS/QZSS precise positioning for land vehicles

100%

Lee B. H. , Jee G. I.

Annual of Navigation

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2013

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tom No. 20

85--96

EN

For ITS (Intelligent Transport Systems), especially for land vehicles, precise position is the prime information. GNSS is the most popular navigation system. Generally, ITS demands lane distinguishable positioning accuracy. However urban area is most environments of land vehicles and the signal blocks of satellite with low elevation angle, multipath error and etc. make unreliable positioning results. Especially, lack of number of visible satellites (fewer than 4 satellites) cannot provide positioning results. QZSS (Quasi-Zenith Satellite System) which operated by Japan has high interoperability. In addition, its elevation angle is very high in long time in Korea. It means QZSS signal can be received in urban area and it can be great advantage for land vehicles. The most positioning errors are occurred by multipath, cycle slip, and etc. For example, multipath error is unexpected momentary error. In order to reduce position error, smoothing technique in position domain is needed. In this paper, precise positioning for land vehicles was evaluated. First, by using QZSS, probability of navigation solution was enhanced. Second, the reliability is improved by smoothing positioning result using Doppler measurement. The analysis was performed by trajectory analysis using precise map data.

PL

Dla inteligentnych systemów transportowych, zwłaszcza w odniesieniu do pojazdów lądowych, dokładna informacja o pozycji jest pierwszorzędna. Systemy satelitarne (GNSS) to obecnie najbardziej popularne systemy nawigacyjne. Zasadniczo inteligentne systemy transportowe wymagają znajomości pozycji determinowanej warunkami drogowymi, a obszary miejskie stanowią środowisko, w którym porusza się największa liczba pojazdów lądowych. Takie ograniczenia, jak przesłanianie niskich satelitów, błąd wielodrożności i tym podobne powodują, że pozycje wyznaczane metodami satelitarnymi stają się mało wiarygodne. Brak wyznaczeń może być spowodowany zwłaszcza brakiem dostatecznej liczby widocznych satelitów (mniej niż cztery). QZSS (Quasi-Zenitalny System Satelitarny), uruchomiony w Japonii, cechuje się w tym względzie niezwykle korzystnymi cechami. W dodatku jego wysokość topocentryczna przez długi czas jest bardzo duża dla obserwatora znajdującego się w Korei. Oznacza to, że sygnał tego systemu może być odbierany w obszarze miejskim, co stanowi bardzo korzystną cechę dla pojazdów lądowych. Większość błędów pozycji wynika w tym wypadku z błędu wielodrogowości, przeskoków fazy i tym podobnych. Na przykład, wielodrogowość obrazuje się jako chwilowe, niespodziewane odchylenie pozycji. Dla zmniejszenia tego rodzaju błędów niezbędna jest technika wygładzania pozycji. W artykule ocenie poddano dokładność pozycjonowania pojazdów lądowych. Po pierwsze poprzez zastosowanie QZSS poprawiono prawdopodobieństwo poprawnego rozwiązania, po drugie poprzez zastosowanie technik wygładzania z użyciem pomiarów dopplerowskich poprawiono wiarygodność wyznaczeń. Analizy wyników dokonano przez analizę trajektorii, odnosząc ją do dokładnych danych mapy.

2

The effect of silicon content on the pitting corrosion of duplex stainless steel weldment

80%

Lee B. H. , Lee H. J. , Kang D. W. , Lee H. W.

Archives of Materials Science and Engineering

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2014

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tom Vol. 67, nr 2

60--69

EN

In this study, the effect of Si content at a welded DSS on the pitting resistance was investigated. Design/methodology/approach: The δ-ferrite fraction increased due to addition of Si, and the amount of γ2 decreased. In the ferric chloride pitting test, the weight reduction range decreased due to an increase in the Si content. As to the location, pittings occurred intensively at the grain boundary or within the austenite grain due to the difference in PREN caused by the differential solid solubility in each phase. Findings: As a result of the potentiodynamic polarization test, while the Epit(Critical Pitting Potential) of all specimens depending on the temperature were observed to be similar at froom temperature up to 45°C, the reduction range of the Epit was found to be small at the temperature higher than 45°C as Si content increased. This was found to be because of formation of SiO2 in the passive film. Research limitations/implications: Higher the addition of Si, the more the number of pittings generated at the grain boundary decreased as the coherence of the passive film increased by the Si accumulated at the boundary. Originality/value: In this study, we intend to investigate the effect of Si element addition on the pitting resistance of the duplex stainless steel welding zone.

3

Biological collections as reference base for biodiversity assessment in the Republic of Korea

80%

Lee B. H. , Cho Y. B. , Lee E. H.

Fragmenta Faunistica

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1997

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tom 40

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nr 16

207-213

EN

Biological collections in 72 depositories of South Korea were surveyed. The number of specimens attained 5 144 409 in total, consisting of 4 103 000 animals, 1 034 825 plants and 6 584 fossils. The average numbers of specimens and species for each collection were 71 450 and 1 130 respectively. The most frequent were in the class range of 10 000-50 000 specimens and 0-100 species each. Twenty one of 45 depositories answered that 80% of their collections are well managed. As regards documentation, only 24% of the collections were electronically databased. The number of species represented by type specimens in the collections and taxonomic experts turned out to be 577 and 207 each. Considering the deplorable situation of the collection status, it is strongly suggested that immediate actions for capacity building by networking databases of the collections, man-power training and setting up of the National Museum of Natural History are urgently needed to provide resource base for biodiversity assessment as well as to respond properly to the Convention on Biological Diversity.

PL

Przejrzano 72 kolekcje biologiczne w Korei Południowej. Stwierdzono, że z ogólnej liczby 5 144 409 okazów, przechowywanych w tych kolekcjach - 4 103 000 to okazy zwierzęce, 1 034 825 - roślinne, a 6 584 - skamieniałości, Średnia liczba okazów i gatunków przypadająca na jedną kolekcję wynosi odpowiednio 71 450 i 1 130. Najliczniejsze są kolekcje przechowujące od 10 000 do 50 000 okazów oraz od 0 do 100 gatunków. Spośród 45 badanych kolekcji biologicznych dwadzieścia jeden odpowiedziało, że 80% ich kolekcji jest dobrze opracowana. Tym niemniej, tylko 24% spośród nich posiada elektroniczną dokumentację. Rozważając aktualny status kolekcji biologicznych w Korei Południowej, wydaje się konieczne podjęcie prac nad stworzeniem elektronicznej bazy informacyjnej oraz powołanie Narodowego Muzeum Historii Naturalnej jako niezbędnego organu odpowiedzialnego za prowadzenie badań oceniających bioróżnorodność zgodnie z założeniami Konwencji o Biologicznej Różnorodności.

4

Sjogren's syndrome: An old tale with a new twist

80%

Lee B. H. , Tudares M. A. , Nguyen C. Q.

Archivum Immunologiae et Therapiae Experimentalis

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2009

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tom 57

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nr 1

57-66

5

Atomistic Analysis Of Radiation-Induced Segregation In Ion-Irradiated Stainless Steel 316

70%

Lee G.-G. , Jin H.-H. , Chang K. , Lee B. H. , Kwon J.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 2B

1179--1184

EN

Stainless steel (SS) is a well-known material for the internal parts of nuclear power plants. It is known that these alloys exhibit radiation-induced segregation (RIS) at point defect sinks at moderate temperature, while in service. The RIS behavior of SS can be a potential problem by increasing the susceptibility to irradiation-assisted stress corrosion cracking. In this work, the RIS behavior of solute atoms at sinks in SS 316 irradiated with Fe4+ ions were characterized by atom probe tomography (APT). There were torus-shaped defects along with a depletion of Cr and enrichment of Ni and Si. These clusters are believed to be dislocation loops resulting from irradiation. The segregation of solutes was also observed for various defect shapes. These observations are consistent with other APT results from the literature. The composition of the clusters was analyzed quantitatively almost at the atomic scale. Despite the limitations of the experiments, the APT analysis was well suited for discovering the structure of irradiation defects and performing a quantitative analysis of RIS in irradiated specimens.

6

Identification of MsHsp23 gene using annealing control primer system

70%

Lee K.-W. , Kim K.-H. , Kim Y.-G. , Lee B. H. , Lee S.-H.

Acta Physiologiae Plantarum

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2012

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tom 34

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nr 2

EN

To identify potential candidates for acquiring stress tolerance, a new annealing control primer (ACP) system was used to identify the differentially expressed genes. Alfalfa (Medicago sativa L.) seedlings were exposed to various abiotic stresses such as cold (4°C for 6 h), heat (42°C for 6 h), salt (300 mM for 6 h), drought (withdrawing irrigation for 48 h), copper (500 µM for 6 h), cadmium (500 µM for 6 h), and arsenic (500 µM for 6 h). Primer sets 41 and 93 were differentially expressed and identified as same sequence, which represents a mitochondrial small heat-shock protein encoding gene, MsHsp23. This band was markedly increased or induced in alfalfa under heat, salt, and arsenic stresses. Differential expression of MsHsp23 was further evaluated by Northern blot analysis. Temporal expression analysis showed that mRNA pool was altered as early as 1 h of treatment. Thus, differential accumulation of MsHsp23 under heat, salt, and arsenic stresses suggests its potential involvement in diverse abiotic stress tolerance, and thereby making a target for further molecular analysis.

7

Phylogenetic study of the suborder Arthropleona [Insecta: Collembola] based on morphological characters and 18S rDNA sequence analysis

70%

Lee B. H. , Hwang U. W. , Kim W. , Park K. H. , Kim J. T.

Polskie Pismo Entomologiczne

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1995

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tom 64

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nr 1-4

8

Human mesenchymal stem cell transplantation promotes functional recovery following acute spinal cord injury in rats

51%

Lee K. H. , Suh-Kim H. , Choi J. S. , Jeun S.-S. , Kim E. J. , Kim S.-S. , Yoon D. H. , Lee B. H.

Acta Neurobiologiae Experimentalis

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2007

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tom 67

|

nr 1

EN

Many attempts have been made in animals to produce cellular regeneration in the spinal cord using a variety of transplanted cell types. The present study was to investigate whether transplantation of human mesenchymal stem cells (hMSCs) into the spinal cord after contusion injury promotes a functional outcome. Spinal cord injury (SCI) was induced using an NYU impactor and hMSCs were transplanted 1 week after SCI. Behavioral testing was performed weekly for 2 months. Somatosensory (SSEPs) and motor evoked potentials (MEPs) were recorded to determine functional recovery. Hindlimb performance was modestly improved in the transplanted group based on BBB scaling and pain tests. SSEP latencies in the transplanted group were significantly shorter than in the media-treated group. Pathologically, LacZ and hTau positive cells were located at the injury and adjacent sites. The data indicate improvement in functional outcome in animals treated with hMSC transplantation compared to media-treated animals.

9

Atomistic Analysis Of Radiation-Induced Segregation In Ion-Irradiated Stainless Steel 316

41%

Lee G.-G. , Jin H.-H. , Chang K. , Lee B. H. , Kwon J.

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nr 2