• 제목/요약/키워드: Step Chain

검색결과 358건 처리시간 0.025초

고전압 대용량을 위한 새로운 인버터 토폴로지 (A New Inverter Topology for High Voltage and High Power Applications)

  • 김태훈;최세완;박기원;이왕하
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
    • /
    • 제52권2호
    • /
    • pp.80-86
    • /
    • 2003
  • In this paper, a new three-phase voltage-source inverter topology for high voltage and high Power applications is proposed to improve the quality of output voltage waveform. A chain converter which is used as an auxiliary circuit generates a ripple voltage and injects it to the conventional 12-step inverter. Thus, the injection of the ripple voltage results in 36-step operation with a link and 60-step operation with two links. The proposed inverter is compared to the conventional multilevel inverter in the viewpoint of ratings of phase- shifting transformers, switching devices and capacitors employed. The proposed scheme is simple to control capacitor voltages compared to the conventional schems and is cost effective for high voltage and high power application over several tens of MVA. The proposed approach is validated through simulation, and the experimental results are provided from a 2KVA laboratory prototype.

Thermal and Mechanical Properties of Polyurethanes based on Novel Chain Extender

  • Lee Dong-Won;Kim Won-Gi;Park Jun-Ho;Im Sang-Gyu;Son Tae-Won
    • 한국섬유공학회:학술대회논문집
    • /
    • 한국섬유공학회 1998년도 가을 학술발표회논문집
    • /
    • pp.66-69
    • /
    • 1998
  • Most segmented polyurethanes are prepared from a two-step method where the polyol is end-capped with an excess of diisocyanate, followed by chain extension with stoichiometric amount of chain extender, In the final polymer the hard and soft segments tend to segregate, due to thermodynamic immiscibility and the differences in chemical structure between hard and soft segments, and produce a phase separated morphology of hard segment-rich and soft segment-rich phase. (omitted)

  • PDF

Synthesis of Novel Carboacyclic Nucleosides with Vinyl Bromide Moiety as Open-chain Analogues of Neplanocin A

  • Choi, Myung-Hee;Kim, Hee-Doo
    • Archives of Pharmacal Research
    • /
    • 제26권12호
    • /
    • pp.990-996
    • /
    • 2003
  • A novel carboacyclic nucleoside analogue, 9-[2-bromo-4-hydroxy-3-hydroxymethyl-2-butenyl] adenine, and its derivatives were designed and synthesized as open-chain analogues of neplanocin A. The syntheses were accomplished via the coupling of adenine or pyrimidine bases to the key intermediate allylic bromide 7. The bromide 7 was prepared from epichlorohydrin in a seven step process in a 54% overall yield. The synthesized compounds were evaluated for their antiviral activity against the polio virus, HSV and HIV.

물류(物流) 아웃소싱 전략(戰略) 결정요인(決定要因) 및 최적(最適) 모델 (Determinants and Optimum Modelling of Logistics Outsourcing Strategy)

  • 송계의
    • 무역상무연구
    • /
    • 제13권
    • /
    • pp.283-302
    • /
    • 2000
  • The firms aim to acquire services and costs advantage from logistics outsourcing strategy. But it is very important to select optimum service provider. A checklist of the criteria for the evaluation of service providers follows : service quality, low cost, logistics information system, service network, financial stability, investments in plant and equipment, management attitude and lookout for the future strategic fit, cultural and psychological barriers etc. Also, a 8-step implement of logistics outsourcing strategy will be of help for maximizing benefits of logistics outsourcing. It follows : 1-step : logistics environment analysis, 2-step : check service provider availability, 3-step : logistics outsourcing determinant analysis, 4-step : select of optimum service provider, 5-step : contract with optimum service provider, 6-step : identify of remaining barriers, 7-step : performance of logistics outsourcing, 8-step : evaluation.

  • PDF

Green Supply Chain Integration and Technology Innovation Performance in SMEs: A Case Study in Indonesia

  • EFFENDI, Mohamad Irhas;WIDJANARKO, Hendro;SUGANDINI, Dyah
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제8권4호
    • /
    • pp.909-916
    • /
    • 2021
  • The purpose of the research to analyze SMEs' technological innovation performance in the Special Region of Yogyakarta based on green supply chains. This study's technology innovation performance is influenced by environmental management practices, green supply chain integration, and supply chain knowledge-sharing. This research is important because many SMEs are underdeveloped in terms of technology innovation performance. Technology innovation performance shows that innovation has a multi-dimensional ecological performance in organizations. Therefore, SMEs' sustainable supply chain could be achieved by managing operations, support, and information by focusing on environmental and social issues to maximize the entire chain. This study used primary data. The number of respondents in this study was 200 SMEs that have implemented green supply chain management practices. The data collection method used was a questionnaire. The data analysis technique tool used is a two-step approach to SEM-AMOS. The results of this study indicate that SMEs are willing to implement a green supply chain to increase their performance. The technological innovation performance model of this study is acceptable. The findings of this research suggest that companies must be encouraged to maintain and increase the implementation of green supply chain integration and better supply chain knowledge-sharing with improved technological innovation performance enhancements.

脂肪酸에 依한 Pepsin의 競走的 억제 (Competitive Inhibition of Pepsin by Carboxylic Acids)

  • 신홍대
    • 대한화학회지
    • /
    • 제14권2호
    • /
    • pp.161-168
    • /
    • 1970
  • In order to obtain the more effective evidence, supporting the hypothesis which have been previously described by former report that pepsin (EC 3.4. 4.1) forms a hydrophobic bond with the nonpolar side chain of its substrate, the inhibitory effect of carboxylic acids(from formic acid to iso-butyric acid) on the activity of pepsin to the synthetic dipeptide, N-Carbobenzoxy-L-glutamyl-L-tyrosine, was discussed. The kinetic study showed that the inhibition by carboxylic acids was competitive. The Kidecreased with increasing size of the inhibitor molecule. The $-{\Delta}F^{\circ}$increased linearly with increasing number of carbon atoms in the hydrocarbon chain of the inhibitor. It was confirmed that the hydrophobic bond between more than one side chain of amino acid residues(phenylalanine) in the binding region of the active center of pepsin and the side chain of amino acid residues in the substrate was formed as the first step of its enzymic mechanism. The inhibitory effect of carboxylic acids was due to the competition of the hydrocarbon group of the carboxylic acids with the side chain of the substrate for the hydrophobic binding site(the side chain of phenylalanine) of the pepsin.

  • PDF

One-step형 친수무공형 폴리우레탄 수지 합성과 코팅 처리한 의류용 직물의 물성 (The Synthesis of One-step Type Hydrophilic Non-porous Polyurethane Resin and the Physical Property of its Coated Fabric for the Garment)

  • 양성용;김현아;김승진
    • 한국염색가공학회지
    • /
    • 제23권2호
    • /
    • pp.131-139
    • /
    • 2011
  • This study surveyed on the synthesis of one-step type hydrophilic non-porous PU resin and the physical property of the coated fabric for the garment. Three kinds of chain extender such as MEG, 1,4-BD and NPG were used for the preparation of one-step type hydrophilic non-porous PU resin in order to examine the effect of chain extender on the physical properties of PU-coated fabric. And the effects of isocyanate on the physical properties of PU coated fabric were surveyed by mixing with various TDI and MDI ratios. In addition, the physical properties of the coated fabric treated with one-step type hydrophilic non-porous PU resin were examined according to the pre-treatment conditions such as cire finishing. Finally, the washing durability of the coated fabrics was assessed. The coated fabrics treated with PU resin synthesized with PEG1000, MEG and TDI/MDI (6/4) showed the best physical properties. Considering the pre-treatment conditions, best performance of hydraulic pressure, water vapor permeability, and water repellency were obtained with top roller rotation ratio of 150% under 50 ton pressure at $170^{\circ}C$.

선반용 STEP-NC 파트 프로그래밍 및 XML의 채용 (Part programming with STEP-NC turning data model and XML adaptation)

  • 정대혁;이병언;서석환
    • 한국경영과학회:학술대회논문집
    • /
    • 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
    • /
    • pp.257-264
    • /
    • 2004
  • 분산 제조 시스템간의 협업을 가능케 하는 e-Manufacturing paradigm 의 성공을 위해서는 CAD-CAM-CNC chain 의 제조 분야뿐만 아니라 SCM, ERP, CRM 등의 상위 시스템과의 제품 및 가공 정보의 원활한 흐름이 필수적이다. STEP 과 STEP-NC 는 이를 해결할 표준으로 자리매김 할 것으로 기대되고 있다. 본 논문은 STEP-NC 의 국내 promotion 차원에서 참고문헌 [1]의 밀링용 파트프로그래밍 소개에 이어: 1) 선반용 데이터 모델, 2) 선반용 파트 프로그램의 작성 방법, 3) XML 을 이용한 파트 프로그램의 표현 방법들을 소개하고, 4) STEP-NC 기반의 생산 환경 구축을 위한 방안을 기술하였다.

  • PDF

사진기록의 디지털화 사례분석과 전략모델 제안에 관한 연구 (A Study on Establishing a Strategy Model Through Analyzing Cases of Digitization of Photographs)

  • 김장환;박주석
    • 한국기록관리학회지
    • /
    • 제9권1호
    • /
    • pp.121-150
    • /
    • 2009
  • 본 연구는 시각문화 패러다임의 등장을 염두에 두고 사진기록의 의미를 재조명함으로써, 사진기록을 디지털화하는 데 필요한 디지털화 전략모델을 수립하고자 하였다. 디지털화 전략모델은 사진기록을 디지털화할 때 필수적으로 고려해야 할 이슈를 고려하여 프로젝트 라이프 사이클과 디지털화 사슬(digitization chain) 모형을 적용함으로써 일반적인 참조모델로서의 프로세스를 제시하는 방향으로 설계되었다. 크게 Pre-project 단계, Production 단계, Post-project 단계의 세 단계로 나뉘고, 세부적으로 (1) 프로젝트 전체 계획 수립 및 관리, (2) 디지털화 대상 사진기록 선별, (3) 디지털 변환 및 품질 관리, (4) 보존 및 접근 이용의 네 단계로 구분된다. 실질적인 사진기록의 디지털화 전략은 디지털화 객체의 생애 주기에 근거한 연속적인 디지털화 사슬 모형을 기반으로, 생성된 디지털화 객체의 품질을 보장할 수 있도록 설계하였다. 각 단계는 기본적인 프로세스와 그에 대한 세부 내용 및 체크 리스트로 구성되어 있다.

The Information System Management and Its Infrastructure for Supply Chain Management as Antecedents of Financial Performance

  • MUNEER, Saqib
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제7권1호
    • /
    • pp.229-238
    • /
    • 2020
  • A model is presented in this paper to provide understanding of the supply chain integration and supply chain information practices' impact on the manufacturing industries. The supply chain information practices play a crucial role in sharing information between the members of SC network. Thus, it is important to develop a comprehensive understanding of the differences and similarities among ISI and information management. It will allow firms to systematically evaluate and carefully choose the information strategy. The empirical findings of this research offer essential and interesting insights about what role SCI, supply chain information and Supply chain ISI play in determining Malaysia's financial performance. The theoretical gaps addressed in this study are of significant importance, since a little empirical evidence is available regarding system infrastructure and supply chain information management's effectiveness. This research provides further paths of exploring system infrastructure and information management, thereby defining the manufacturing industries' next step in SCM struggle i.e. modifying total integrated SC principle in other manufacturing firms. The Resource-based theory discovered organizational resources as an essential organizational success ingredient. Therefore, in order to recognize its potential value, internal resources, for instance, information system and management must be fully utilized.