• Title/Summary/Keyword: Assembly structure

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A Novel Al-Bridged Trinuclear Iron(II) Bis(imino)pyridyl Complex with Catalytic Ethylene Polymerization Behavior

  • Long, Zerong;Li, Zhongquan;Ma, Ning;Wu, Biao
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2537-2543
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    • 2011
  • A self-assembled Al-bridged diiminopyridine-based ligand (3) was synthesized and characterized by FT-IR, ESI-MS and NMR spectroscopy. Electron spectral titrations were performed to confirm the formation of a novel trinuclear bis(imino)pyridyl iron(II) complex (4) upon addition of $FeCl_2$ into Al-bridged ligand 3 in methanol solution. Simultaneously, a typical bis(imino)pyridine-iron(II) complex (2) was synthesized and fully characterized. The X-ray crystal study of the iron(II) complex 2 disclosed a five-coordinate, distorted square-pyramidal structure with the tridentate N^N^N ligand and chlorides. The optimal molecular structure of 4 was obtained by means of molecular mechanics, which showed that each iron atom in the complex 4 is surrounded by two chlorides, a tridentate N^N^N ligand and one oxygen atom, supporting considerations about the possibility of six-coordinate geometry from MMAO or the ethylene access. A comparison of 4 with the reference 2 revealed a remarkable decrease of the catalytic activity and MMAO consumption (activity up to $0.41{\times}10^3\;kg\;{mol_{Fe}}^{-1}h^{-1}bar^{-1}$, Al/Fe = 650 for 4 and $7.02{\times}10^3\;kg\;{mol_{Fe}}^{-1}h^{-1}bar^{-1}$, Al/Fe = 1600 for 2).

Analyzing Differences of Binary Executable Files using Program Structure and Constant Values (프로그램의 구조와 상수 값을 이용하는 바이너리 실행 파일의 차이점 분석)

  • Park, Hee-Wan;Choi, Seok-Woo;Seo, Sun-Ae;Han, Tai-Sook
    • Journal of KIISE:Software and Applications
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    • v.35 no.7
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    • pp.452-461
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    • 2008
  • Binary diffing is a method to find differences in similar binary executables such as two different versions of security patches. Previous diffing methods using flow information can detect control flow changes, but they cannot track constant value changes. Biffing methods using assembly instructions can detect constant value changes, but they give false positives which are due to compiling methods such as instruction reordering. We present a binary diffing method and its implementation named SCV which utilizes both structure and value information. SCV summarizes structure and constant value information from disassembled code, and matches the summaries to find differences. By analyzing a Microsoft Windows security patches, we showed that SCV found necessary differences caused by constant value changes which the state-of-the-art binary diffing tool BinDiff failed to find.

Synthesis of Carbon Nanotubes Supported PtCo Electrocatalysts and Its Characterization for the Cathode Electrode of PEMFC (탄소나노튜브에 담지된 PtCo 촉매 제조 및 PEMFC Cathode 전극 특성)

  • Jung, Dong-Won;Park, Soon;Kang, Jung-Tak;Kim, Jun-Bom
    • Korean Journal of Materials Research
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    • v.19 no.5
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    • pp.233-239
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    • 2009
  • The electrocatalytic behavior of the PtCo catalyst supported on the multi-walled carbon nanotubes (MWNTs) has been evaluated and compared with commercial Pt/C catalyst in a polymer electrolyte membrane fuel cell(PEMFC). A PtCo/MWNTs electrocatalyst with a Pt:Co atomic ratio of 79:21 was synthesized and applied to a cathode of PEMFC. The structure and morphology of the synthesized PtCo/MWNTs electrocatalysts were characterized by X-ray diffraction and transmission electron microscopy. As a result of the X-ray studies, the crystal structure of a PtCo particle was determined to be a face-centered cubic(FCC) that was the same as the platinum structure. The particle size of PtCo in PtCo/MWNTs and Pt in Pt/C were 2.0 nm and 2.7 nm, respectively, which were calculated by Scherrer's formula from X-ray diffraction data. As a result we concluded that the specific surface activity of PtCo/MWNTs is superior to Pt/C's activity because of its smaller particle size. From the electrochemical impedance measurement, the membrane electrode assembly(MEA) fabricated with PtCo/MWNTs showed smaller anodic and cathodic activation losses than the MEA with Pt/C, although ohmic loss was the same as Pt/C. Finally, from the evaluation of cyclic voltammetry(CV), the unit cell using PtCo/MWNTs as the cathode electrocatalyst showed slightly higher fuel cell performance than the cell with a commercial Pt/C electrocatalyst.

The Comparison of Apartment Management System Between Korea and Japan (한국과 일본의 공동주택 관리제도 비교)

  • Kang, Hye-Kyoung
    • Journal of Family Resource Management and Policy Review
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    • v.10 no.3
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    • pp.45-62
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    • 2006
  • This research is carried out to inspect the Apartment Management System of Japan, to examine the similarities and differences between the Korean Apartment Management System and the Japanese Apartment Management System. First, as the basis law of apartment management, there exists the Building Unit Ownership Act, the Promotion Law fur Adequate Mansion Management of Japan, the Housing Law, Housing Execution Law and Rule of Korea. Second, the Association of Apartment Owners, an organization of owners of apartments in Japan and the Commission of the Representatives of the Occupants in Korea become the subject of maintenance. The Japan structure is made of the Assembly, the Director and the President. The Korean structure is made of Regular and Temporary Conferences and elected Officers(1 president, at least 2 directors and at least 1 inspector). The Commission of the Representatives of the Occupants and the Organization of Owners of Apartments make bylaws and diverse maintenance rules. Third, the foremost reason why the Korean structure of maintenance of apartments is less efficient than Japan is because of the small number of people dispatched to the living-environment maintenance team and their short terms. It is necessary to grow professionals related to this sector and to have enough public servants that specialize in this. Fourth, although it is compulsory to make long term plans for maintenance based on the Housing Law, because the reserve fund is decided by the maintenance rule(with no compulsory standards of reservation) of each apartment, it is difficult to reserve an adequate amount of reserve fund. So as in the example of the state of Hawaii in America, based on long term plans for maintenance, an execution rule of the Housing Law should be made which enforces to reserve at least 50 percent of future maintenance expenses.

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Adaptive length SMA pendulum smart tuned mass damper performance in the presence of real time primary system stiffness change

  • Contreras, Michael T.;Pasala, Dharma Theja Reddy;Nagarajaiah, Satish
    • Smart Structures and Systems
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    • v.13 no.2
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    • pp.219-233
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    • 2014
  • In a companion paper, Pasala and Nagarajaiah analytically and experimentally validate the Adaptive Length Pendulum Smart Tuned Mass Damper (ALP-STMD) on a primary structure (2 story steel structure) whose frequencies are time invariant (Pasala and Nagarajaiah 2012). In this paper, the ALP-STMD effectiveness on a primary structure whose frequencies are time varying is studied experimentally. This study experimentally validates the ability of an ALP-STMD to adequately control a structural system in the presence of real time changes in primary stiffness that are detected by a real time observer based system identification. The experiments implement the newly developed Adaptive Length Pendulum Smart Tuned Mass Damper (ALP-STMD) which was first introduced and developed by Nagarajaiah (2009), Nagarajaiah and Pasala (2010) and Nagarajaiah et al. (2010). The ALP-STMD employs a mass pendulum of variable length which can be tuned in real time to the parameters of the system using sensor feedback. The tuning action is made possible by applying a current to a shape memory alloy wire changing the effective length that supports the damper mass assembly in real time. Once a stiffness change in the structural system is detected by an open loop observer, the ALP-STMD is re-tuned to the modified system parameters which successfully reduce the response of the primary system. Significant performance improvement is illustrated for the stiffness modified system, which undergoes the re-tuning adaptation, when compared to the stiffness modified system without adaptive re-tuning.

Case Analysis Study on 3D printed parametric Fashion Products (3D프린팅 파라메트릭 패션제품 사례분석연구)

  • Ahn, Jin-wook;Jang, Joong-sik
    • Journal of the Korea Convergence Society
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    • v.12 no.12
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    • pp.169-176
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    • 2021
  • This study aims to explore the formativeness of 3D printed parametric fashion products while parametric design-based 3D printed fashion products are increasing. As a research method, theoretical review was conducted and formative properties of 3D printing parametric fashion products were derived, and cases of 3D printing parametric fashion products were collected and examined into three types of clothing, shoes, and accessories. As a result of the study, it was possible to confirm the shape with the motif of a natural object, and structurally, the economical optimal structure, assembly structure, and natural structure were confirmed. was found to use natural and achromatic colors. Through the understanding of the formativeness of 3D printing parametric fashion products presented in this study, it is expected that it will be used as basic data to understand the spread and formative flow of parametric-based fashion products.

A Study on the Supplement of Political Elite and the Characteristics of Federalism Structure in Russia : focusing on the Comparison with B.Yeltsin and V.Putin (러시아의 정치 엘리트 충원 방식과 연방제 구조의 성격)

  • Lee, Yeoung-hyeong
    • International Area Studies Review
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    • v.14 no.3
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    • pp.502-523
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    • 2010
  • A federal system speaks for a political system that the principle of the common sovereignty among the local governments is applied. The basic purpose of the system is to make institutional devices capable of striving for the mutual cooperation in a greater political unit, reflecting a minority race's right and demand by decentralizing a state authority into the individual region. The basic purpose for formation of a federal system is realized when a form for the supplement of political elite personnels has a autonomous nature by the subject of a federal structure. During from B.Yeltsin to V.Putin, a form for the supplement of political elite personnels into the local governments has changed by a political purpose of a central government, In company with this change, the character of federalism in Russia has been also changed. Accordingly, this study has treated a subject about how the political elite personnels of local assembly men, governors of a state, assemblymen of both Houses, and the president of Russia are suppled, and also how such a form for the supplement of political elite personnels has changed the character of federalism in Russia.

A Design of Mooring Line for the Buoy-Enabled Underwater Surveillance System (부이형 수중감시 시스템에서 계류라인의 구조 설계)

  • Byun, Yang-Hun;Choi, Bum-Kyu;Oh, Tae-Won
    • The Journal of Korean Institute of Information Technology
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    • v.16 no.12
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    • pp.41-47
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    • 2018
  • The buoy-enabled underwater surveillance system is a device that is installed in a particular sea area and operated for a certain period of tine and moved to another sea area after recovery. In this paper, a mooring method which is applied for a buoy-enabled underwater surveillance system was selected to maintain installation and enure stable operation. Also, the structure of the mooring line was designed. Two-point mooring method was selected considering interference with the communication cable of array-assembly. The composite structure of buoy chain, nylon rope, and anchor chain is designed as the basic component of mooring line. For the verification of design, a numerical simulation and wave tank experiment were performed. Their results were confirmed similarity in test condition. Finally, the mooring lines were designed for the environment of the sea trial location. The mooring line produced by the final design confirmed the stability above the significant wave height considered in the design on the sea trial.

A Study on Development of Owner's Standard Specification Structure for Modular Building (모듈러 전문 시방서 개발을 위한 체계 구축)

  • Nam, Sunghoon;Park, Honggeon;Kim, Kyungrai
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.3
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    • pp.12-21
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    • 2019
  • Specification is an important document for securing safe construction and improving quality as well as the contract document. Currently, the specifications used in modular buildings in Korea are only the construction specification, and most of the contents are used by borrowing the standard specifications of the building, so the contents of the modular buildings can not be reflected and it is contents are similar to the guideline book. The current status of domestic specification for modular buildings is affecting the quality of modular buildings. Therefore, we analyze activity through monitoring the modular process of modular buildings and analyze systematically relationship by applying IDEF modeling with analyzed activity. As result this paper proposes a structure of special specification specialized in modular building through generalization. The major classifications were divided into three stages : factory construction, transportation, and on-site installation. The specification structure was divided into 32 types of construction items from the floor slab assembly of the factory production to the joint finish of the on site installation in accordance with the opinion of experts.

Whole-Genome Characterization of Alfalfa Mosaic Virus Obtained from Metagenomic Analysis of Vinca minor and Wisteria sinensis in Iran: with Implications for the Genetic Structure of the Virus

  • Moradi, Zohreh;Mehrvar, Mohsen
    • The Plant Pathology Journal
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    • v.37 no.6
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    • pp.619-631
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    • 2021
  • Alfalfa mosaic virus (AMV), an economically important pathogen, is present worldwide with a very wide host range. This work reports for the first time the infection of Vinca minor and Wisteria sinensis with AMV using RNA sequencing and reverse transcription polymerase chain reaction confirmation. De novo assembly and annotating of contigs revealed that RNA1, RNA2, and RNA3 genomic fragments consist of 3,690, 2,636, and 2,057 nucleotides (nt) for IR-VM and 3,690, 2,594, and 2,057 nt for IR-WS. RNA1 and RNA3 segments of IR-VM and IR-WS closely resembled those of the Chinese isolate HZ, with 99.23-99.26% and 98.04-98.09% nt identity, respectively. Their RNA2 resembled that of Canadian isolate CaM and American isolate OH-2-2017, with 97.96-98.07% nt identity. The P2 gene revealed more nucleotide diversity compared with other genes. Genes in the AMV genome were under dominant negative selection during evolution, and the P1 and coat protein (CP) proteins were subject to the strongest and weakest purifying selection, respectively. In the population genetic analysis based on the CP gene sequences, all 107 AMV isolates fell into two main clades (A, B) and isolates of clade A were further divided into three groups with significant subpopulation differentiation. The results indicated moderate genetic variation within and no clear geographic or genetic structure between the studied populations, implying moderate gene flow can play an important role in differentiation and distribution of genetic diversity among populations. Several factors have shaped the genetic structure and diversity of AMV: selection, recombination/reassortment, gene flow, and random processes such as founder effects.