Recently, the using of prefabricated temporary equipments is increasing in the industrial field because it can reduce the installation and dismantling period. The various types of prefabricated temporary equipments are manufacturing with various materials in domestic and overseas countries. However, those equipments should win the safety certificate according to the "Governmental Notification about Safety Certification" which regulate the member-based safety certification. It tends to cause over performance of temporary equipments because it couldn't consider structural benefit of the prefabricated products. As the result of this study, it is concluded that the establishment of new safety certification standard for the prefabricated temporary equipments is resonable and the movable scaffold is appropriate for those prefabricated temporary equipment. The movable scaffolds are using as single structure and cannot be expands horizontally. Other types of temporary equipments are using as complex structure which can freely expand horizontally according to the main structure. From the results of the study, the standard of vertical compression performance of prefabricated movable scaffolds should be more than double the performance of single main frame. Other test items of safety certification standard should be fixed when the Notification is amended. The prefabricated temporary equipments which are adopted for the safety standard on assembled structure should be used, moved and kept in assembled state and not separated discretionally. The establishment of new standard for the assembled structure based on this study leads to the development of various types of temporary equipments using structural efficiency of prefabricated structure.

This work examines the feasibility for estimating existing tensile stress on a stressed wire using the permeability of magnetic flux. A closed magnetic circuit has been constructed to induce magnetic flux inside a steel wire. With different tension stress levels on a wire, the permeability of magnetic flux on the wire has been measured. Two different experimental case studies have been conducted for the examination of sensitivity of permeability of magnetic flux on the stressed wire. One is a varying-length stress test, and the other is a fixed-length stress test. The results show that the permeability of magnetic flux in the varying-length stress test is inversely proportional to the applied stress, while the permeability in the fixed-length stress test is linearly proportional to the applied stress on the stressed wire. It is thus expected that the permeability of magnetic flux on a wire can be a promising indicator for the inspection of its tensile stress.

PURPOSES : This study aimed to evaluate the feasibility of AASHTO86 design method for Bonded Concrete Overlay. METHODS : The Feasibility of AASHTO86 design method for Bonded Concrete Overlay is investigated based on the following study : i) Sensitivity analysis of designed service life of Bonded Concrete Overlay by major design input for AASHTO86 guide. ii) Comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life by AASHTO86. iii) Finding the stress component influence the potential distress of Bonded Concrete Overlay based on 3-d FEM analysis. iv) Exploring the limitation of AASHTO86 in the aspect of design input. RESULTS : Sensitivity analysis showed that the condition of existing pavement significantly on the Bonded Concrete Overlay life. Also the overlay thickness affect the Bonded Concrete Overlay life. The comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life showed relatively good agreement when the early distress sections are excluded in comparison. Bonding stress occurred at the interface may be larger than the bond strength used in the specification of Bonded Concrete Overlay construction. CONCLUSIONS : Bonded Concrete Overlay life predicted by the AASHTO86 may not be reliable. Number of points to improve the reliability in the design of Bonded Concrete Overlay are suggested in this study.

PURPOSES : This study aims to review the possibility of developing a road snow-melting system that can prevent slip accidents by maintaining a constant temperature of the winter roads and enhance performance of structures, including improvement of compressive strength by mixing carbon nanotube (hereafter referred to as CNT) with cement paste, the basic material. METHODS : To achieve the above purpose, an experiment was conducted by mixing power-type CNT and wrap-type CNT up to cement paste formulation by weight of 0.0wt%~4.1wt% in accordance with "KS L ISO 679(of cement strength test method)", and compressive strength was measured at 28 days of curing. In addition, the volume resistivity of the specimen was measured to test thermal and electrical characteristics, and the rate of temperature changes in specimen surface by power consumption was measured by passing electricity through the cross-sections of the specimen. Meanwhile, the criteria for checking the performance as a road snow-melting system was determined as volume resistivity of 100Ω·cm or less. RESULTS : A comparative analysis between specimen with 0wt% CNT content in plain status and specimen containing various types of CNTs was carried out. From its results, it was found that compressive strength increased approximately 19%, showing the highest rate when 0.2wt% of wrap-type CNT was contained, but volume resistivity of 100Ω·cm or less appeared only in specimens containing more than 0.2wt% CNT. In addition, it was observed that the surface temperature increased by 4.62℃ per minute on average in specimens containing 3.2wt% CNT. CONCLUSIONS : In this study, CNT was examined as an underlying material for a road snow-melting system, and the possibility of developing the road now-melting system was reviewed by conducting various experiments using CNT-Cement composites. From the experimental results, the specimens were found to have a superior performance when compared to the existing road snow-melting systems that place the heat transfer medium such as copper on the road. However, satisfactory strength performance were not obtained from the specimen containing CNT(2.0% or more) that functions as a heating element, which leads to the need for reviewing methods to increase the strength by using plasticizer or admixture.

파이로그린공정의 염폐기물처리과정에서 발생되는 주요 산화물 형태의 폐기물에는 희토류폐기물이 있으며 주요 구성 핵종은 Y, La, Ce, Pr, Nd, Sm, Eu, Gd 등 8종이다. 최종적인 희토류폐기물의 형태는 산화물 형태로 발생된다. 본 연구에서는 붕규산 유리계 내에서 희토류 산화물의 유리화 타당성을 평가 하기 위하여 6종의 유리조성을 개발하였다. 희토류 8핵종 혼합에 대한 solubility는 1,200℃에서 25wt% 미만, 1,300℃에서 30wt% 미만 waste loading으로 온도 상승에 따라 증가하는 것으로 나타났으며 liquidus temperature는 균질한 유리가 형성된 20wt% waste loading에서 950℃ 이하로 평가되었다. 희토류 산화물의 유리매질 내 solubility 이상에서는 희토류-oxide-silicate 결정이 생성된 유리세라믹을 이차상으로 형성하였으며 20~25wt% waste loading의 표면균질성이 양호한 유리는 용융온도 1,200~1,300℃ 범위에서 점도 100 poise 이하, 전기전도도 1 S/cm 이상으로 유도가열식 저온용융로설비에서의 운전 용이성이 매우 양호한 것으로 평가되었다. 개발된 유리조성에 대한 기타 물리·화학적 특성 평가를 위한 실험들이 향후 수행될 예정이다.

최근 들어 청각 장애인들에게 정상인들이 소리로부터의 느끼는 청감과 유사한 느낌을 전달하기 위한 방안으로써 시각은 물론 진동감과 같은 촉감을 활용하는 연구가 시도되고 있다. 특히 시각 정보의 보조 감각으로써 스피커나 진동 모터를 이용한 촉감이 제공되는 경우 생동감은 상당히 개선되는 측면이 있으나 정서감 측면에서는 그 효과가 거의 없는 것으로 보고되었다. 따라서 본 연구에서는 유사 청감을 재현할 수 있는 또 하나의 보조 감각으로서 열감을 설정하고 열감이 유사 청감 재현 효과를 가질 수 있는가에 관하여 조사하였다. 이를 위해 열감을 효과적으로 재현할 수 있는 열감 재현 모듈을 구현하였다. 그리고 실험 대상자들에게 시각 정보와 더불어 청각 정보, 진동 촉감, 그리고 열감을 혼합한 다양한 형태의 자극을 제공한 실험을 수행하였다. 실험에서 얻어진 데이터 통계 분석을 통하여 i) 영상과 함께 열감 자극을 제공하거나 또는 ii) 영상과 함께 열감 자극과 진동 자극을 동시에 제공하는 경우가 영상만을 제공하는 경우보다 실험 대상자들이 영상과 소리로부터 느끼는 실제 열감에 더 가까운 유사 열감을 느낄 수 있다는 사실을 확인하였다. 결론적으로 실험 대상자의 피부에 제공되는 열감이 유사 청감 재현 보조 매체로서의 활용 가능성이 있음을 확인할 수 있었다.

The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) project is a next-generation infrared space telescope optimized for mid- and far-infrared observation with a cryogenically cooled 3m-class telescope. It will achieve the high resolution as well as the unprecedented sensitivity from mid to far-infrared range. The FPC (Focal Plane Camera) proposed by KASI as an international collaboration is a near-infrared instrument. The FPC-S and FPC-G are responsible for the scientific observation in the near-infrared and the fine guiding, respectively. The FPC-G will significantly reduce pointing error down to below 0.075 arcsec through the observation of guiding stars in the focal plane. We analyzed the pointing requirement from the focal plane instruments as well as the error factors affecting the pointing stability. We also obtained the expected performance in operation modes. We concluded that the FPC-G can achieve the pointing stability below 0.075 arcsec which is the requirement from the focal plane instruments.

This paper aims to suggest a validity analysis model that would be helpful for local governments considering u-City construction projects and a methodology for them to promote build-transfer-lease (BTL) u-City projects. This methodology mainly uses quanti

Internet and information technology due to the development of rapid changes in the investment environment, the existing securities, or by disassembling the combined financial engineering to create new securities with the development of enlarged minimize losses to investors in financial markets more stable that can be and need a way to invest in this paper, such as individual stocks or a specific index of those derivatives that are linked to the December 1, 2005 and 2010 the market began trading from the phone call attention off new measures to gauge the individual through ELW underlying assets such as stocks or a specific index to minimize the loss of a stable hedge for investors to evaluate the possibility of studying for.

This study has been performed on the full density sintering of Fe nanopowder and the surface hardening by plasma ion nitriding. The Fe sintered part was fabricated by pressureless sintering of the Fe nanopowder at in which the nanopowder agglomerates were controlled to have 0.5-5 sized agglomerates with 150 nm Fe nanopowders. The green compact with 46% theoretical density(T.D.) showed a homogeneous microstructure with fine pores below 1 . After sintering, the powder compact underwent full densification process with above 98%T.D. and uniform nanoscale microstructure. This enhanced sintering is thought to be basically due to the homogeneous microstructure in the green compact in which the large pores are removed by wet-milling. Plasma ion nitriding of the sintered part resulted in the formation of '- equilibrium phase with about 12 thickness, leading to the surface hardening of the sintered Fe part. The surface hardness was remarkably increased from 176 for the matrix to 365 .

As local governments have difficulties in financing U-City projects very much at once, investment from private sectors is necessary. This paper propose methodologies about preliminary feasibility study of private investment in U-City construction. They are concrete shapes of feasibility study methodologies of KDI PIMAC to meet U-City construction. They are feasibility study of private investment by policies of the local government and the central government, methodologies of financial VFM analysis to cost during a U-City project, methodologies of qualitative VFM analysis of project management, U-City service quality and operation efficiency of U-City infrastructure . They give concrete examples of the Ansan U-City project.

가압경수로 원전의 농축폐액건조설비에서 발생된 농축폐액 건조물을 유리화 하는 방안이 연구되어 왔다. 중저준위 방사성폐기물을 유리화할 경우 최종 생성물은 내구성이 우수하고 현저한 부피저감 효과의 장점을 가지고 있다. 붕산농축폐액에 대한 유리화 타당성 연구는 분말시료의 전처리 방법 개발, 유리조성 프로그램을 이용한 유리개발 및 실증시험으로 수행되었다. 분말시료에 대한 전처리 방안으로는 유리화설비에 투입하기 전에 고형성을 갖도록 펠렛화하는 것이다. 농축폐액 성분중 Na와 B의 함량 분포는 유리속에 용융되는 정도와 설비로부터의 폐기물 배출·처리에 영향을 주기 때문에 이를 고려하여 유리조성이 개발되어야 한다. 실증시험에서는 폐기물 투입률, 배기체 특성 및 최종 생성물인 유리고화체의 특성이 검토되었다. 본 연구는 붕산농축폐액에 대한 유리고화체의 물리화학적 특성을 검토하고 유리화 타당성을 확인하는데 목적이 있다.

국제해사기구는 '1969년 민사책임협약'과 '1971년 국제기금협약' 채택 이후 유류오염사고 규모의 증대 및 물가인상률에 따라 협약의 개정의정서를 채택하여 유류오염사고 피해보상율의 한도를 증대시켜 왔으며, 최근에는 '2003년 추가기금협약'을 채택하여 보상한도액을 1조원 이상으로 증대시켰다. 우리나라는 '1992년 민사책임협약' 및 '1992년 국제기금협약'에만 가입하였으나 2007년 12월 허베이 스피리트호 사고 이후 '2003년 추가기금협약'의 가입 필요성이 증대되었다. 본 연구는 '2003년 추가기금협약'의 가입에 따른 경제적 타당성을 정량적 및 정성적인 측면에서 분석하였다. 정량적인 분석은 자료의 한계상 과거 사고자료 및 국제기금의 분담금 자료 등을 이용하여 수행하였으며, 그 결과는 가입에 따른 편익이 비용을 초과하는 것으로 나타났다. 정성적인 측면은 피해자 구제를 위한 재원문제, 유류운송에 의한 경제적인 수혜자의 부담문제, 우리나라의 국제적인 위상 등을 살펴봄으로써 협약가입의 당위성이 높음을 분석하였다.

Energy saving and decreasing green gas are critical issue today, so various technologies to save energy and decrease carbon dioxide in plant process have been applied to many industrial area. In this paper, the feasibility of condenser heat recovery in power plant was reviewed by verifying 에너지 평형 and simulating power plant model. Some ways to compose proper system and their possibilities were also reviewed. The amount of heating recovery and changed heating capacity were verified by simulation. There is noticeable improvement of plant performance in simulated result. Future study and experiment will show more evident results.

본 논문에서는 지진으로부터 구조물을 효과적으로 보호하기 위하여 MR 엘라스토머(MRE)를 이용한 새로운 형태의 스마트 기초격리 시스템을 제안하고, 이에 대한 내진성능을 파악하였다. MRE는 자성물질을 포함한 실리콘 혹은 고무로써 자기장에 의해 강성이 변하는 스마트 재료이다. 기초격리 시스템은 토목 및 건축분야에서 구조물의 내진성능 향상을 위해 가장 널리 쓰이는 장치로 지반과 구조물을 격리시켜 구조물에 가해지는 입력 하중을 감소시켜주는 장치이다. 기존 수동형태의 기초격리 장치는 다양한 입력하중에 대한 적응성이 부족하고 기초격리 장치에서의 과도한 변위 등의 단점이 있는 반면, 새로 제안한 시스템은 제어 가능한 강성범위가 넓어 이를 개선할 수 있다. MRE를 이용한 기초격리 장치의 성능을 확인하기 위하여 기초격리 장치를 도입한 단층 및 5층의 건물에 대해 다양한 역사지진 하중을 이용하여 수치해석을 수행하였다. 수치해석 결과, 제안된 시스템은 기존 수동형태의 시스템에 비해 구조물의 응답 및 기초격리장치의 변위를 감소시키는 데 탁월한 효과가 있음을 확인하였다.

It is hot issue to get the competitiveness of product through reliability-growth as well as availability and safety in almost high-technology industry including military, chemistry, nuclear, telecommunication, transportation service and so on. In advanced countries, worldwide leading companies have tried to improve and develop high-reliability product as well as reliability management system(IEC60300). We investigate reliability certification systems for product and management system. Additionally, we study the feasibility on the adoption of dependability management system(IEC60300) by empirical survey on companies with product-reliability certification(R-mark) in Korea.