• Korean Chemical Engineering Research
• /
• 제56권1호
• /
• pp.14-23
• /
• 2018

The effect of dodecylbenzene sulfonic acid (DBSA) with different addition amount of DBSA ($M_{DBSA}$), temperatures and solvent-to-oil ratio (SOR, v/v) on asphaltene aggregation in a solvent deasphalting system was investigated. Increasing the $M_{DBSA}$ at SOR 10 and $55^{\circ}C$ caused the asphaltene removal ratio (ARR) to increase first, then maximize at 1 wt% of $M_{DBSA}$ and then decrease continuously. Based on the SARA (saturate, aromatic, resin, asphaltene) composition, the adsorption amount of DBSA on the asphaltene surface and the self-aggregation of the DBSA, the reason for the change in ARR with $M_{DBSA}$ was found due to the adsorption mechanism. In addition, the asphaltene-resin-DBSA colloidal size confirmed the change of adsorption behavior between the asphaltene and DBSA. Based on the results of this study, a hypothetical adsorption mechanism of DBSA on asphaltene aggregation in the solvent deasphalting system was conceived of and proposed.

• 비파괴검사학회지
• /
• 제19권1호
• /
• pp.1-7
• /
• 1999

교류전위차법 (alternating current potential drop : ACPD)을 이용하여 이차원 표면균열을 갖고 있는 상자성체 (paramagnetic material)의 모드 I (opening mode) 응력확대계수($K_I$)를 실험적으로 평가하기 위하여 하중에 따른 교류전위차 변화(change in ACPD)를 연구하였다. 아울러 하중에 의한 전위차 변화의 원인 그리고 전위차 변화에 미치는 자속(magnetic flux) 탈자(demagnetization) 및 균열길이의 영향을 연구하였다. 상자성체의 교류전위차는 인장하중을 증가시킬수록 선형적으로 감소하였다. 전위차 감소의 원인은 균열선단 주위의 도전율(conductivity)이 인장하중의 증가에 따라 증가하고 이는 시험편의 저항과 내부 인덕턴스를 감소시키기 때문이다. 도전율의 변화는 균열선단 주변의 응력상태에 의존하기 때문에 일정 $K_I$ 변화에 따른 전위차 변화량은 균열길이에 의존하지 않는다. 하중에 의한 전위차변화량은 시험편 주위의 자속의 유무에 영향을 받지만 탈자의 유무에는 영향을 받지 않는다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
• /
• pp.137-140
• /
• 2003

Shorted-turns can have significant effects on a generator and its performance. Shorted-turn sensor for synchronous generator's field winding have been developed. One of effective method detecting inter-turn short circuits on round rotor winding is a method using sensor detecting. But the method needs duplicate design of sensor for characteristic change according to types and forms of generator Thus sensing skill without sensor depend on change of electric property in generator. For the reason, this paper presents shorted-turns phenomenon and the characteristic analysis of shorted-turns In synchronous generator by using 2-D finite element method(FEM).

• Journal of Preventive Medicine and Public Health
• /
• 제44권1호
• /
• pp.14-21
• /
• 2011

Objectives: The regulatory changes in Korea during the national economic crisis 10 years ago and in the current global recession were analyzed to understand the characteristics of deregulation in labor policies. Methods: Data for this study were derived from the Korean government's official database for administrative regulations and a government document reporting deregulation. Results: A great deal of business-friendly deregulation took place during both economic crises. Occupational health and safety were the main targets of deregulation in both periods, and the regulation of employment promotion and vocational training was preserved relatively intact. The sector having to do with working conditions and the on-site welfare of workers was also deregulated greatly during the former economic crisis, but not in the current global recession. Conclusions: Among the three main areas of labor policy, occupational health and safety was most vulnerable to the deregulation in economic crisis of Korea. A probable reason for this is that the impact of deregulation on the health and safety of workers would not be immediately disclosed after the policy change.

• 산업공학
• /
• 제10권2호
• /
• pp.79-90
• /
• 1997

Documents in a traditional PDM(Product Data Management) system have been managed in a form of scanned document files or electronic documents developed by specific tools. Though each tool manages documents with its own systematical methods, it has drawbacks in data search, data integration and interchange, etc. For this reason, in this research we propose an efficient document management system for PDM by using the SGML(Standard Generalized Markup Language), one of CALS and ISO standards for document interchanges. Among documents to be managed in PDM, the engineering change notification (ECN) is taken into account. The DTD (Document Type Definition) has been constucted based on the logical analysis of the documents format, In addition, based on the DTD, DB classes have been designed by object-oriented paradigms and a prototype for document input/output and search has been developed using UniSQL ORDBMS (Object-Relational DBMS) and PowerBuilder under the client/server environment.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2011년도 추계 학술논문 발표대회
• /
• pp.11-12
• /
• 2011

The Construction Standard Production Unit(CSPU) has been used for the standard cost estimate in public and private construction projects. However, It is difficult to reflect the various site attributed variation in productivity using existing CSPU. The reason is that a criteria which site should be selection for enactment and/or revision of CSPU is not established. This study aims to provide essential data to be used for analyzing the labor factors in a way to secure efficiency and reliability of CSPU.

• 한국멀티미디어학회논문지
• /
• 제20권4호
• /
• pp.721-729
• /
• 2017

This study examined the dramatic devices that the production team made for the studio progress in the survival music entertainment program of open narrative structure in which the audience participated through MBC 'The King of Mask Singer'. The reason for the need for dramatic equipment is that the studio Audience who participated in the process of the program crossed the situations of flow, selection, and enjoyment. As a result of the research, the production team of 'The King of Mask Singer' was found to have a device of time margin, lighting and background image, and role of MC in order to change the progress of the studio and that the participating audience naturally change their roles.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 추계학술대회 논문집
• /
• pp.210-213
• /
• 2003

Short-circuited can have significant effects on a generator and its performance. One of effective method detecting inter-turn short circuits on round rotor winding is a method using sensor detecting. But the method needs duplicate design of sensor for characteristic change according to types and forms of generator. Thus rotor shorted-turn diagnosis method without sensor is needed for detecting short turn when generator is driven. Diagnosis method without sensor depend on change of electric property in generator For the reason, this paper presents characteristic analysis of shorted-turns in generator by detecting the output voltage of generator.

• 한국콘텐츠학회논문지
• /
• 제11권7호
• /
• pp.497-507
• /
• 2011

본 논문은 건축자재들을 컴포넌트와 패턴으로 조립하여 패턴 단위로 건축설계가 효율적으로 이루어질 수 있도록 하는 스틸하우스 설계 인터페이스를 개발한다. 또한 이 기술을 이용하여 건축의 공정에 설계, 분석, 변경정보, 조립 등의 건축설계를 시뮬레이션을 통하여 건축의 손쉬운 변경과 비용을 효과적으로 절감하기 위한 기술을 지원하는 조립 건축설계 시스템 개발을 목적으로 한다. 특히 설계자와 사용자도 패턴을 이용하여 쉽게 건축물을 변경시킬 수 있으며 변경에 따라 필요한 자재들의 패턴 정보와 변경된 건축물의 설계도가 자동 생성된다. 또한 개인의 숙련도나 지식 가시화를 통해 발생할 수 있는 지식검색 역시 구현 목표로 한다.

• 분석과 대안
• /
• 제6권1호
• /
• pp.195-222
• /
• 2022

From the economic development perspective, economic growth should accompany structural improvement in order to meet complex demands from a society. In the context of development economics, economic growth is critically dependent on successful structural advancement. The issue of structural change is also important for advanced economies as the landscape of modern industry is changing fast. Many advanced countries of slow growth are experiencing dawdling changes in industry structure. However, there is no definitive answer to the question of whether there is a causal relationship between structural change and growth. This study empirically assesses the relationship between structural change or 'speed' thereof and economic growth in developed countries of OECD. Rather than looking into the causes of structural changes, this study simply measures structural changes in OECD economies and examines if structural change is really contributing to growth. The reason why this study focuses on advanced countries of OECD is rather obvious; technological innovation and emergence of new industries pressure these countries to restructure their economies to address these new challenges though they are at stages well beyond conventional industrialization. And structural rigidity can always limit growth even in advanced countries. The main results of this study can be summarized as a positive relationship between 'change and growth'. 'Change' in this study refers to changes in the industrial structure based on value-added and was analyzed to have a close positive relationship with economic growth. This result is consistent with arguments of early development economists emphasizing structural upgrade as an indispensable process for growth and development. The result of this study potentially confirms that the main argument of development economics is valid also for advanced economies. One of our results suggests that business/professional services and social services should be main targets for restructuring for advanced economies. The rational may be that rapid convergence of manufacturing and services is a key for structural advancement in the era of new technologies. Obviously, as manufacturing technology and production are standardized, it is difficult to secure international competitiveness through traditional manufacturing alone and the role of R&D, design, logistics, and marketing is becoming more important.