• Title/Summary/Keyword: unambiguous

Search Result 111, Processing Time 0.031 seconds

Infrared Spectroscopy of Imidazole Trimer in Helium Nanodroplets: Free NH Stretch Mode

  • Lee, Seul-Ki;Lee, Seung-Jun;Ahn, Ah-Reum;Kim, Yu-Sic;Min, Ah-Reum;Choi, Myong-Yong;Miller, Roger E.
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.3
    • /
    • pp.885-888
    • /
    • 2011
  • We report the first vibrational band assignment of imidazole trimer (IMT) solvated in helium nanodroplets. Several congested vibrational bands of imidazole (IM) clusters were obtained in the frequency region of $3513-3515\;cm^{-1}$ and vibrationally resolved due to the extremely low temperature (0.37 K) and very weak solutesolvent interaction environments of helium droplets. The unambiguous free NH band assignment was achieved with an aid of pick-up oven temperature dependence and vibrational transition moment angle (VTMA) experiments as well as density functional theory (DFT) calculations. The band at $3514.3\;cm^{-1}$ is attributed to the free NH stretching mode of linear IMT clusters, easily formed by the dipole-dipole interactions of IM in ultracold helium nanodroplets.

Theoretical and Experimental 31P NMR and ESI-MS Study of Hg2+ Binding to Fenitrothion

  • Koo, In-Sun;Ali, Dildar;Yang, Ki-Yull;vanLoon, Gary W.;Buncel, Erwin
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.6
    • /
    • pp.1257-1261
    • /
    • 2009
  • We present the theoretical and experimental results of $^{31}P$ NMR and low energy CID MS/MS study of $Hg^{2+}$ binding to fenitrothion (FN). The calculated $^{31}P$ NMR chemical shifts order for FN with $Hg^{2+}$ complex is in good agreement with experimental $^{31}P$ NMR chemical shifts order. The experimental and theoretical $^{31}P$ NMR study of organophosphorus pesticide with $Hg^{2+}$ gives to important information for organophosphorus pesticide metal complexes. ESI-MS and low energy CID MS/MS experiments of $Hg^{2+}$-FN complexes combined with accurate mass measurements give insight into the metal localization and allow unambiguous identification of fragments and hydrolysis products.

Advances in the design of high-rise structures by the wind tunnel procedure: Conceptual framework

  • Simiu, Emil;Yeo, DongHun
    • Wind and Structures
    • /
    • v.21 no.5
    • /
    • pp.489-503
    • /
    • 2015
  • This paper surveys and complements contributions by the National Institute of Standards and Technology to techniques ensuring that the wind tunnel procedure for the design of high-rise structures is based on sound methods and allows unambiguous inter-laboratory comparisons. Developments that enabled substantial advances in these techniques include: Instrumentation for simultaneously measuring pressures at multiple taps; time-domain analysis methods for estimating directional dynamic effects; creation of large simulated extreme directional wind speed data sets; non-parametric methods for estimating mean recurrence intervals (MRIs) of Demand-to-Capacity Indexes (DCIs); and member sizing based on peak DCIs with specified MRIs. To implement these advances changes are needed in the traditional division of tasks between wind and structural engineers. Wind engineers should provide large sets of directional wind speeds, pressure coefficient time series, and estimates of uncertainties in wind speeds and pressure coefficients. Structural engineers should perform the dynamic analyses, estimates of MRIs of wind effects, sensitivity studies, and iterative sizing of structural members. The procedure is transparent, eliminates guesswork inherent in frequency domain methods and due to the lack of pressure measurements, and enables structural engineers to be in full control of the structural design for wind.

Congenital Heart Disease: a Pictorial Illustration of Putting Segmental Approach into Practice

  • Yeung, Tse Hang;Park, Eun-Ah;Lee, Ying Cheong;Yoo, Jin Young;Lui, Choi Yu
    • Investigative Magnetic Resonance Imaging
    • /
    • v.19 no.4
    • /
    • pp.205-211
    • /
    • 2015
  • The human heart is a complex organ in which many complicated congenital defects may happen and some of them require surgical intervention. Due to the vast complexity of varied anatomical presentations, establishing an accurate and consistent nomenclature system is utmost important to facilitate effective communication among pediatric cardiologists, cardiothoracic surgeons and radiologists. The Van Praagh segmental approach to the complex congenital heart disease (CHD) was developed in the 1960s and has been used widely as the language for describing complex anatomy of CHD over the decades. It utilizes a systematic and sequential method to describe the cardiac segments and connections which in turn allows accurate, comprehensive and unambiguous description of CHD. It can also be applied to multiple imaging modalities such as echocardiogram, cardiac CT and MRI. The Van Praagh notation demonstrates a group of three letters, with each letter representative for a key embryologic region of cardiac anatomy: the atria, ventricles and great vessels. By using a 3-steps approach, we can evaluate complex CHD precisely and have no difficulties in communicating with other medial colleague. This pictorial essay revisits the logical steps of segmental approach, followed by a pictorial illustration of its application.

Firms Collaboration in the E-Business Environment A System Dynamics Simulation

  • Kim, Bowon
    • Proceedings of the Korea Society for Simulation Conference
    • /
    • 2001.05a
    • /
    • pp.163-163
    • /
    • 2001
  • The primary research questions in this paper are why and how competing firms collaborate, not compete, in the virtual marketplace, e.g., B2B marketplace in the Internet environment. In order to answer the questions, we take on a system dynamics simulation approach: we consider two broad e-collaboration strategies: · Exclusive e-business strategy If the firm adopts this strategy, it allocates all of its resources (available for e-business development) to its own e-business capability building only. · Collaborative e-business strategy When the firm adopts a collaborative e-business strategy, it invests not only in its own, but also the industrys e-business capability building. From the system dynamics simulation results, we conclude that e-collaboration pays off in the long run: although it is hard to tell whether the collaborative strategy is better than the exclusive one during the initial period, it is unambiguous that the collaborative e-business strategy Performs much better in the long run. We infer that such collaboration could occur when the firms realize that they benefit from the expansion of the market demand due to their collaboration. That is, in order for such collaboration between competing firms to be sustainable, such collaboration should create more demand in the market so that each company could earn more profit even if it gets less in terms of market share.

  • PDF

Unambiguous 3D Surface Measurement Method for a Micro-Fresnel Lens-Shaped Lenticular Lens Based on a Transmissive Interferometer

  • Yoon, Do-Young;Kim, Tai-Wook;Kim, Minsu;Pahk, Heui-Jae
    • Journal of the Optical Society of Korea
    • /
    • v.18 no.1
    • /
    • pp.37-44
    • /
    • 2014
  • The use of a laser interferometer as a metrological tool in micro-optics measurement is demonstrated. A transmissive interferometer is effective in measuring an optical specimen having a high angle slope. A configuration that consists of an optical resolution of 0.62 micron is adapted to measure a specimen, which is a micro-Fresnel lens-shaped lenticular lens. The measurement result shows a good repeatability at each fraction of facets, however, a reconstruction of the lens shape profile is disturbed by a known problem of $2{\pi}$-ambiguity. To solve this $2{\pi}$-ambiguity problem, we propose a two-step phase unwrapping method. In the first step, an unwrapped phase map is obtained by using a conventional unwrapping method. Then, a proposed unwrapping method based on the shape modeling is applied to correct the wrongly unwrapped phase. A measured height of each facet is compared with a profile result measured by AFM.

The Taxonomy Criteria of DoS Attack Pattern for Enhanced Intrusion Detection System (향상된 침입 탐지 시스템을 위한 DoS 공격 유형의 분류 체계)

  • Kim, Kwang-Deuk;Park, Seung-Kyun;Lee, Tae-Hoon;Lee, Sang-Ho
    • The Transactions of the Korea Information Processing Society
    • /
    • v.6 no.12
    • /
    • pp.3606-3612
    • /
    • 1999
  • System(IDS) hasn't Protection capability for various security attacks perfectly. Because, It is probably affected by IDS's workload caused by treating all kind of the characteristics and attack patterns of system and can't probe all of the attack types being intelligently different with attack patterns. In this paper, we propose a new taxonomy criteria about DoS(denial of service attacks) to make more efficient and new real time probing system. It's started with an idea that most of the goal oriented systems make the state of system operation more unambiguous than general purpose system. A new event caused the state of the system operation to change and classifying a category of the new events may contribute to design the IDS.

  • PDF

A Representation of Product Model for the Piping System Based on the Object_Oriented Paradigm (객체지향기술을 이용한 배관시스템 모델의 표현)

  • Jong-Kap Lee;No-Sang Park
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.31 no.3
    • /
    • pp.19-30
    • /
    • 1994
  • The modeling of a product data is becomming more and more important in engineering environment, especially for the development of CAD/CAM system as a basis of computer integrated manufacturing system. Model is a formalized representation of the real world, and modeling is the task to identify, abstract, and formalize the product information into an unambiguous representation. In this study, the piping system, one of typical product of ship outfitting system, is modeled. The STEP idea is followed to provide a common mechanism to represent the product information throughout the life-cycle, and the object oriented paradigm is used in the analysis and design of the model. The definitions given within this model are independent of the specific application domain so that the same methodology can be used for other purpose.

  • PDF

Study on Error Reduction in Dual Wavelength Digital Holography Using Modified Fine Map (수정된 화인 맵을 이용한 2-파장 홀로그래피와 잡음 제거 연구)

  • Yu, Young-Hun
    • Korean Journal of Optics and Photonics
    • /
    • v.22 no.3
    • /
    • pp.129-133
    • /
    • 2011
  • Dual-wavelength holography has better axial range than single-wavelength holography, allowing unambiguous phase imaging but at the expense of increased noise. We have studied error reduction in dual wavelength holography using a modified fine map. The fine map is successful in measurement and has shown error reduction when the height of the object is less than the appled wavelength, but is unstable when the step height is larger than that wavelength. We have modified the fine map and we have found that the modified fine map was successful in measurement and error reduction even though the height of object was larger than the wavelength.

Ribosomal Crystallography: Peptide Bond Formation, Chaperone Assistance and Antibiotics Activity

  • Yonath, Ada
    • Molecules and Cells
    • /
    • v.20 no.1
    • /
    • pp.1-16
    • /
    • 2005
  • The peptidyl transferase center (PTC) is located in a protein free environment, thus confirming that the ribosome is a ribozyme. This arched void has dimensions suitable for accommodating the 3'ends of the A-and the P-site tRNAs, and is situated within a universal sizable symmetry-related region that connects all ribosomal functional centers involved in amino-acid polymerization. The linkage between the elaborate PTC architecture and the A-site tRNA position revealed that the A-to P-site passage of the tRNA 3'end is performed by a rotatory motion, which leads to stereochemistry suitable for peptide bond formation and for substrate mediated catalysis, thus suggesting that the PTC evolved by genefusion. Adjacent to the PTC is the entrance of the protein exit tunnel, shown to play active roles in sequence-specific gating of nascent chains and in responding to cellular signals. This tunnel also provides a site that may be exploited for local co-translational folding and seems to assist in nascent chain trafficking into the hydrophobic space formed by the first bacterial chaperone, the trigger factor. Many antibiotics target ribosomes. Although the ribosome is highly conserved, subtle sequence and/or conformational variations enable drug selectivity, thus facilitating clinical usage. Comparisons of high-resolution structures of complexes of antibiotics bound to ribosomes from eubacteria resembling pathogens, to an archaeon that shares properties with eukaryotes and to its mutant that allows antibiotics binding, demonstrated the unambiguous difference between mere binding and therapeutical effectiveness. The observed variability in antibiotics inhibitory modes, accompanied by the elucidation of the structural basis to antibiotics mechanism justifies expectations for structural based improved properties of existing compounds as well as for the development of novel drugs.