• Title/Summary/Keyword: two-level resolution

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Optical Design of a Snapshot Nonmydriatic Fundus-imaging Spectrometer Based on the Eye Model

  • Zhao, Xuehui;Chang, Jun;Zhang, Wenchao;Wang, Dajiang;Chen, Weilin;Cao, Jiajing
    • Current Optics and Photonics
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    • v.6 no.2
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    • pp.151-160
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    • 2022
  • Fundus images can reflect ocular diseases and systemic diseases such as glaucoma, diabetes mellitus, and hypertension. Thus, research on fundus-detection equipment is of great importance. The fundus camera has been widely used as a kind of noninvasive detection equipment. Most existing devices can only obtain two-dimensional (2D) retinal-image information, yet the fundus of the human eye also has spectral characteristics. The fundus has many pigments, and their different distributions in the eye lead to dissimilar tissue penetration for light waves, which can reflect the corresponding fundus structure. To obtain more abundant information and improve the detection level of equipment, a snapshot nonmydriatic fundus imaging spectral system, including fundus-imaging spectrometer and illumination system, is studied in this paper. The system uses a microlens array to realize snapshot technology; information can be obtained from only a single exposure. The system does not need to dilate the pupil. Hence, the operation is simple, which reduces its influence on the detected object. The system works in the visible and near-infrared bands (550-800 nm), with a volume less than 400 mm × 120 mm × 75 mm and a spectral resolution better than 6 nm.

Crystal Structure of the Metallo-Endoribonuclease YbeY from Staphylococcus aureus

  • Jinwook Lee;Inseong Jo;Ae-Ran Kwon;Nam-Chul Ha
    • Journal of Microbiology and Biotechnology
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    • v.33 no.1
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    • pp.28-34
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    • 2023
  • Endoribonuclease YbeY is specific to the single-stranded RNA of ribosomal RNAs and small RNAs. This enzyme is essential for the maturation and quality control of ribosomal RNA in a wide range of bacteria and for virulence in some pathogenic bacteria. In this study, we determined the crystal structure of YbeY from Staphylococcus aureus at a resolution of 1.9 Å in the presence of zinc chloride. The structure showed a zinc ion at the active site and two molecules of tricarboxylic acid citrate, which were also derived from the crystallization conditions. Our structure showed the zinc ionbound local environment at the molecular level for the first time. Molecular comparisons were performed between the carboxylic moieties of citrate and the phosphate moiety of the RNA backbone, and a model of YbeY in complex with a single strand of RNA was subsequently constructed. Our findings provide molecular insights into how the YbeY enzyme recognizes singlestranded RNA in bacteria.

The Role of ADR in the Resolution of the Copyright Disputes (ADR을 통한 저작권분쟁 해결에 관한 검토)

  • Kim, Sun-Jeong
    • Journal of Arbitration Studies
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    • v.21 no.2
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    • pp.85-112
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    • 2011
  • These days utilization of copyright in daily life and economic activities is becoming more important than ever, and IT technology is developing day by day. Along with those fact, copyright infringement and dispute is naturally increasing. This thesis dealt with the 3 different issues of ADR on copyright. The First part, introduce ADR system that was performed by Korea Copyright Committee according to Copyright law. This paper evaluate the committee's efforts to provide resolution of copyright disputes via conciliation was effective. So it needs to be look over several countries' ADR, beside conventional judicial remedy. And Korea's copyright conciliation system which is successfully operating also introduced. Second, In many countries, including South Korea are take advantage of conciliation as the way to settle down the dispute over copyright. Furthermore, looked over if we can use arbitration as tool to settle dispute or not. Currently in Korea, patent dispute is handled by Industrial Property Dispute Conciliation Committee(The Invention Promotion Act Ch.5) and Layout-design Review and Mediation Committee(The Act on the Layout-designs of Semiconductor Integrated Circuits Art.29-34), but using performance of those two committee is still too low. In comparison, the copyright committee, a affiliation organization of the ministry of culture, sports and tourism has much more result in conciliation compare with patent dispute. Copyright disputes has arbitrability of it's subject-matter and many regulating organs are interested in it. (especially, binding of arbitral award and final resolution). Take advantage of both conciliation and arbitration could be good way to resolve copyright disputes. Third, the writer look at the proposal on the creation of Northeast Regional Center for Intellectual Property ADR. Because of the nature of copyright and rapid development of internet technology, international use of work become more frequent and accordingly infringement cases are increasing. The role of commercial arbitration regimes and institutions which has progressed significantly worldwide level, but which has only just begun in the intellectual property ADR area, leads also to a clash of often very different legal cultures and protection in a market economy. International cooperation in regional area with conflict interests becomes an important alternative. But it will depend on the building of regional institutions and mechanisms. The feasibility of this proposal and preconditions were examined. Establishment of new international organization requires a lot of time, cost and efforts. And risk of failure is much too high. Therefore factual, statistical review should be preceded. In addition, technical measures, such as on-line arbitration is necessary to review also. Furthermore in order to establish new organization, the relative law, legal environment, public sentiment and international compliance must be carefully considered with factual review about the needs and economic benefits of each country Yet on complex regulatory matters such as IP and ADR, a great deal of the potential benefits from international standards arises not from the international legal framework nor even the formal content of national legislation, but from the informed and effective use made of the possibilities within the system, including by policymakers and regulators.

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The Effects of Gender Cue and Antecedent Case on the Immediacy of Pronominal Resolution (대명사의 성별단서와 선행어 격이 참조해결의 즉각성에 미치는 효과)

  • JaehoLee
    • Korean Journal of Cognitive Science
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    • v.4 no.1
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    • pp.51-86
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    • 1993
  • The purpose of this study was to investigate on-line comprehension processing in pronoun resolution. The two important constraints investigated in this study were the gender cue of pronoun and the antecedent case. Using antecedent probe recognition task. Experiment 1 investigated the effects of gender cues and antecedent cases on probe recognition time. There were on signigicant effects of employed variable. This result suggest the possibilty of immediate antecedent assignment depending on the degree of syntactic constraints satisfaction. In Experiment 2. using antecedent probe recognition task. the primed activation level differences between antecedents and non-antecedents over time-course intervals from 0 to 250msec were measured. The effect of gender cues was obtained over 0-250msec time-course condition. This indicates that the gender cues can determine the assignment of proper antecedent for a pronoun. In Experiment 3, subect-case pronouns were used only:Unambiguous gender cues were given and the time-course intervals of 250 and 750msec were employed. A signigicant interaction effect of antecedent cases with probe conditions was obtained. All the results of this research suggest that gender cues are powerful constraints for pronoun resolution.

Comparisons of Collection 5 and 6 Aqua MODIS07_L2 air and Dew Temperature Products with Ground-Based Observation Dataset (Collection 5와 Collection 6 Aqua MODIS07_L2 기온과 이슬점온도 산출물간의 비교 및 지상 관측 자료와의 비교)

  • Jang, Keunchang;Kang, Sinkyu;Hong, Suk Young
    • Korean Journal of Remote Sensing
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    • v.30 no.5
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    • pp.571-586
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    • 2014
  • Moderate Resolution Imaging Spectroradiometer (MODIS) provides air temperature (Tair) and dew point temperature (Tdew) profiles at a spatial resolution of 5 km. New Collection 6 (C006) MODIS07_L2 atmospheric profile product has been produced since 2012. The Collection 6 algorithm has several modifications from the previous Collection 5 (C005) algorithm. This study evaluated reliabilities of two alternative datasets of surface-level Tair and Tdew derived from C005 and C006 Aqua MODIS07_L2 (MYD07_L2) products using ground measured temperatures from 77 National Weather Stations (NWS). Saturated and actual vapor pressures were calculated using MYD07_L2 Tair and Tdew. The C006 Tair showed lower mean error (ME, -0.76 K) and root mean square error (RMSE, 3.34 K) than the C005 Tair (ME = -1.89 K, RMSE = 4.06 K). In contrasts, ME and RMSE of C006 Tdew were higher than those (ME = -0.39 K, RMSE = 5.65 K) of C005 product. Application of ambient lapse rate for Tair showed appreciable improvements of estimation accuracy for both of C005 and C006, though this modification slightly increased errors in C006 Tdew. The C006 products provided better estimation of vapor pressure datasets than the C005-derived vapor pressure. Our results indicate that, except for Tdew, C006 MYD07_L2 product showed better reliability for the region of South Korea than the C005 products.

Reliable and High Spatial Resolution Method to Identify the Number of MoS2 Layers Using a Scanning Electron Microscopy

  • Sharbidre, Rakesh Sadanand;Park, Se Min;Lee, Chang Jun;Park, Byong Chon;Hong, Seong-Gu;Bramhe, Sachin;Yun, Gyeong Yeol;Ryu, Jae-Kyung;Kim, Taik Nam
    • Korean Journal of Materials Research
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    • v.27 no.12
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    • pp.705-709
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    • 2017
  • The electronic and optical characteristics of molybdenum disulphide ($MoS_2$) film significantly vary with its thickness, and thus a rapid and accurate estimation of the number of $MoS_2$ layers is critical in practical applications as well as in basic researches. Various existing methods are currently available for the thickness measurement, but each has drawbacks. Transmission electron microscopy allows actual counting of the $MoS_2$ layers, but is very complicated and requires destructive processing of the sample to the point where it will no longer be useable after characterization. Atomic force microscopy, particularly when operated in the tapping mode, is likewise time-consuming and suffers from certain anomalies caused by an improperly chosen set point, that is, free amplitude in air for the cantilever. Raman spectroscopy is a quick characterization method for identifying one to a few layers, but the laser irradiation causes structural degradation of the $MoS_2$. Optical microscopy works only when $MoS_2$ is on a silicon substrate covered with $SiO_2$ of 100~300 nm thickness. The last two optical methods are commonly limited in resolution to the micrometer range due to the diffraction limits of light. We report here a method of measuring the distribution of the number of $MoS_2$ layers using a low voltage field emission electron microscope with acceleration voltages no greater than 1 kV. We found a linear relationship between the FESEM contrast and the number of $MoS_2$ layers. This method can be used to characterize $MoS_2$ samples at nanometer-level spatial resolution, which is below the limits of other methods.

Hybrid Buffer Structured Optical Packet Switch with the Limited Numbers of Tunable Wavelength Converters and Internal Wavelengths (제한된 수의 튜닝 가능한 파장변환기와 내부파장을 갖는 하이브리드 버퍼 구조의 광 패킷 스위치)

  • Lim, Huhn-Kuk
    • Journal of Internet Computing and Services
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    • v.10 no.2
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    • pp.171-177
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    • 2009
  • Optical packet switching(OPS) is a strong candidate for the next-generation internet, since it has a fine switching granularity at the packet level for providing flexible bandwidth, and provides seamless integration between WDM layer and IP layer. Optical packet switching have been studied in two categories: OPS in synchronous and OPS in asynchronous networks. In this article we are focused on contention resolution of OPS in asynchronous networks. The hybrid buffer have been addressed, to reduce packet loss further as one of the alternative buffer structures for contention resolution of asynchronous and variable length packets, which consists of the FDL buffer and the electronic buffer. The OPS design issue for the limited number of TWCs and internal wavelengths is important in the aspect of switch cost and resource efficiency. Therefore, an hybrid buffer structured optical packet switch and its scheduling algorithm is presented for considering the limited number of TWCs and internal wavelengths, for contention resolution of asynchronous and variable length packets. The proposed algorithm could lead to the packet loss improvement compared to the legacy LAUC-VF algorithm with only the FDL buffer.

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Seismic reflection survey in a tidal flat: A case study for the Mineopo area (갯벌 지역에서의 탄성파 탐사: 민어포 조간대 지역의 사례)

  • Jou Hyeong-Tae;Kim Han-Joon;Lee Gwang-Hoon;Choi Dong-Lim;Kim Min-Ji;Cho Hyun-Moo
    • 한국지구물리탐사학회:학술대회논문집
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    • 2002.09a
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    • pp.67-84
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    • 2002
  • A shallow high-resolution seismic reflection survey was carried out at the Mineopo tidal flat on the western coast of Korea. The purpose of the survey was to investigate shallow sedimentary structure of the tidal (fat associated with the recent sea level change. A total of 795 shots were generated at 1 m interval from a 5-kg hammer source and recorded on 48 channels of 100 Hz geophones along two mutually perpendicular profiles. The water-saturated ground condition resulted in suppressed ground rolls by significantly decreasing rigidity. In addition, seismic velocities over 1500 m/s provided easy segregation of reflected arrivals from lower velocity noise. As a consequence, seismic sections were created that are high in resolution and signal to noise ratio as well. The stack sections show that the tidal flat consists of 5 sedimentary sequences above acoustic basement. Although deposition is largely characterized by the transgressive sedimentary facies resulting from sea level rise, erosional surfaces are well-resolved within the sequences.

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Feasibility Study of EEG-based Real-time Brain Activation Monitoring System (뇌파 기반 실시간 뇌활동 모니터링 시스템의 타당성 조사)

  • Chae, Hui-Je;Im, Chang-Hwan;Lee, Seung-Hwan
    • Journal of Biomedical Engineering Research
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    • v.28 no.2
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    • pp.258-264
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    • 2007
  • Spatiotemporal changes of brain rhythmic activity at a certain frequency have been usually monitored in real time using scalp potential maps of multi-channel electroencephalography(EEG) or magnetic field maps of magnetoencephalography(MEG). In the present study, we investigate if it is possible to implement a real-time brain activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, neither on a sensor plane nor on a standard brain model, with a high temporal resolution. In the suggested system, a frequency domain inverse operator is preliminarily constructed, considering the individual subject's anatomical information, noise level, and sensor configurations. Spectral current power at each cortical vertex is then calculated for the Fourier transforms of successive sections of continuous data, when a single frequency or particular frequency band is given. An offline study which perfectly simulated the suggested system demonstrates that cortical rhythmic source changes can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under Pentium4 3.4GHz environment. Two sets of artifact-free, eye closed, resting EEG data acquired from a dementia patient and a normal male subject were used to show the feasibility of the suggested system. Factors influencing the computational delay are investigated and possible applications of the system are discussed as well.

Taxonomy and nomenclature of the Conjugatophyceae (= Zygnematophyceae)

  • Guiry, Michael D.
    • ALGAE
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    • v.28 no.1
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    • pp.1-29
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    • 2013
  • The conjugating algae, an almost exclusively freshwater and extraordinarily diverse group of streptophyte green algae, are referred to a class generally known as the Conjugatophyceae in Central Europe and the Zygnematophyceae elsewhere in the world. Conjugatophyceae is widely considered to be a descriptive name and Zygnematophyceae ('Zygnemophyceae') a typified name. However, both are typified names and Conjugatophyceae Engler ('Conjugatae') is the earlier name. Additionally, Zygnemophyceae Round is currently an invalid name and is validated here as Zygnematophyceae Round ex Guiry. The names of orders, families and genera for conjugating green algae are reviewed. For many years these algae were included in the 'Conjugatae', initially used as the equivalent of an order. The earliest use of the name Zygnematales appears to be by the American phycologist Charles Edwin Bessey (1845-1915), and it was he who first formally redistributed all conjugating algae from the 'Conjugatae' to the orders Zygnematales and the Desmidiales. The family Closteriaceae Bessey, currently encompassing Closterium and Spinoclosterium, is illegitimate as it was superfluous when first proposed, and its legitimization is herein proposed by nomenclatural conservation to facilitate use of the name. The genus Debarya Wittrock, 1872 is shown to be illegitimate as it is a later homonym of Debarya Schulzer, 1866 (Ascomycota), and the substitute genus name Transeauina Guiry is proposed together with appropriate combinations for 13 species currently assigned to the genus Debarya Wittrock. The relationships between Mougeotia, Mougeotiopsis, Mougeotiella, and Transeauina require further resolution, as do many of the other genera referred to the Conjugatophyceae. Type species are designated for genera for which no types were formally selected previously. The number of currently described species of conjugating green algae in AlgaeBase is about 3,500, comprising about 10% of all algal species, with about one third of species referred to the Zygnematales and two-thirds to the Desmidiales. A corresponding 10% of all algal names at the species level and below have been applied to conjugating algae, although a large proportion of these are at the infraspecific level.