• 한국항공우주학회지
• /
• 제48권10호
• /
• pp.821-829
• /
• 2020

항공기 소프트웨어의 건전성 관리시스템은 수행 중에 발생하는 오류를 수리하여 안전성을 제공하고 유지보수 비용을 절감한다. 순서 위배 오류는 개발 단계에서 모두 제거하는 것이 어렵기 때문에 운용 단계에서 자율적으로 수리할 수 있어야 한다. 순서 위배를 자율 수리하기 위한 기존 연구는 각 접근사건의 수행 직전에 접근사건 순서를 비교하여 오류를 진단하기 때문에 접근사건 수에 비례하는 시간 오버헤드를 발생시킨다. 본 논문은 접근사건을 포함하는 함수의 올바른 순서 정보로 오류를 진단하고 해당 함수를 지연시켜 조치하는 기법인 ORS를 제시한다. ORS를 평가하기 위해, 순서 위배 오류를 포함하는 5가지의 합성 프로그램에 기존 연구와 ORS를 적용하여 시간 오버헤드를 측정하였다. 그 결과, 접근 횟수가 약 60번 이상일 때 기존 연구보다 효율적임을 확인하였다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
• /
• pp.277-280
• /
• 2005

Epoxy-mortar composites have been wildly used as finishing and repairing materials in the construction because of their excellent properties. Conventional epoxy-mortars and concretes have an inferior applicability and cost performance ratio due to the two component mixing of the epoxy resin and hardener. In this study, we examined the engineering effect of compressive strength and flexible strength according to the various epoxy-hardener in underwater and humidity environment, and evaluated the hardener types and physical effect of Epoxy mortar using cement binder in underwater and air condition. In this study, it was clarified that the engineering properties of repairing epoxy-motars were effected by the type of hardener.

• 품질경영학회지
• /
• 제10권2호
• /
• pp.10-17
• /
• 1982

Three different manual assembly techniques are evaluated by relating the effects of component quality to the total cost of the product. The results show that the choice of the scrapping or repairing the defective products or alternatively, salvaging the acceptable parts, may effect the total product cost by as much as 400 per cent. This paper emphasizes the need for accurate control quality of parts in assembly if low-cost manufacture is to be achieved.

• 한국멀티미디어학회논문지
• /
• 제8권7호
• /
• pp.953-960
• /
• 2005

모바일 컴퓨팅 환경은 네트워크가 손상되기 쉬우며 모바일 호스트(Mobile Host: MH)를 지원하는 모바일 서포트 스테이션(Mobile Support Station: MSS)이 안정적이지 못하다. 따라서 오류가 발생했을 경우, 저장된 정보를 복구하기 위해서는 많은 양의 네트워크 비용이 요구된다. 안정적인 복구를 위해서는 이미 보내진 메시지를 어떤 방식으로 저장할 것인가 하는 것과 어떤 핸드오프 기법을 사용해서 복구해 낼 것인가 하는 점을 고려해야 한다. 본 논문에서는 모바일 호스트의 이동성에 따라 복구 기법을 달리하는 ST(Switching Trickle) 기법을 제안한다 제안된 기법의 성능평가를 위해 이동성에 따라 점차 증가하는 누적비용을 시뮬레이션 한다. 실험 결과를 통해 기존에 구현된 기법들과 비교하여 제안된 기법에서 전체적인 비용이 감소된 것을 확인할 수 있다. 뿐만 아니라 제안된 기법은 MH의 이동성이 크지 않을 경우. 체크포인트(checkpoint)와 메시지 로그 정보를 안정적으로 저장할 수 있다.

• Composites Research
• /
• 제15권1호
• /
• pp.21-31
• /
• 2002

기존 굴착식 기술의 단점을 극복하기 위해 다양한 비굴착 보수-보강기술이 개발되고 시도되었으나, 이제까지 개발된 비굴착 기술들은 높은 공사비용과 시공의 불편함이라는 결점을 갖고 있다. 본 연구에서는 VARTM(Vacuum Assisted Resin Transfer Molding)과 유리섬유 고분자 복합재료를 이용해 지하매설관을 보수-보강하는 연구를 수행하였다. 개발된 공법은 기존 기술보다 적은 비용과 공사 시간을 필요로 하며 사용되는 장비 또한 간단하다. 신뢰성 있는 공정을 위해 유연한 금형의 역할을 하는 보강재에 수지를 주입한 후, 가압과 진공을 가하는 방법이 시도되었으며, 상용 유전장치인 LACOMCURE를 사용하여 RTM 공정 중 수지의 함침과 경화 상태를 추적하였다. 연구결과를 통해, 적절한 공정 변수 및 온라인 경화 모니터링 기법을 적용한 본 공법이 기존 방법에 비해 많은 장점을 가짐을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제5권4호
• /
• pp.709-715
• /
• 1992

In this study attempts were made to identify the areas of single animal ploughing (SAP) in Bangladesh, causes of its localization and the socio-economic constraints hindering the expansion of the system. To determine the areas of single animal ploughing, 123 upazilas of 15 districts were surveyed. Of them, 16 upazilas were found heavily engaged with this system. A detailed investigation of 469 SAP and 439 double animal ploughing (DAP) farmers revealed that there was significant difference between the two systems in respect of cost of production and yield per unit of land. The benefit/cost (B/C) ratio was higher in SAP system. However, no significant difference was observed in respect of time required for ploughing, intensity of cropping, cost of implements, and cost of repairing implements (except yoke). The study recommends for expansion of SAP system in areas where buffaloes are concentrated. Fro this purpose, logistic and institutional supports need to be made available.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2004년도 학술.기술논문발표회
• /
• pp.105-108
• /
• 2004

The most of former schools facility have been planed and constructed with cement liquid waterproofing which is moth to be desired fir behavior of structure. However. It cause to decline safety for structure and also increase repairing cost that by leakage to behavior for thermal effects, Moreover, It is necessary for establishment fundamental counterplan of maintenance for schools facility to improve educational environment in budget support and proper diagnostic tech. and evaluation, repair reinforcement. In present paper, Firstly, we analyze out leakage and defect of schools facility of ㅇㅇ district office of education. Secondly, suggest the proper diagnostic tech. as leakage factor to develope efficiency of using space for durability and safety from leakage with suggestion the proper diagnostic.

• 한국산업융합학회 논문집
• /
• 제16권1호
• /
• pp.14-20
• /
• 2013

In this study, characteristic of new materials for repairing/reinforcement of sea and underwater structures using urethane were studied experimentally. As a results, following their good result was obtained. Materials and construction methods due to a chemical reaction, so no seams, shape or form, regardless of the variety of civil engineering in the field can be applied. Fast workability, hardening existing concrete compared with 80% in shortening. Than the existing large concrete pouring construction cost could be reduced by more than 30%.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2004년도 추계학술대회
• /
• pp.125-130
• /
• 2004

It is not difficult to see the road repairing. There are many and various machines that can crush road surface. The efficiency and power of the machine depend on crushing head-shape, crushing interval, crushing load, crushing stress, machine's dropping height and roller's kind. The objective of this study is to select the optimal model among ten models of crushing machine with constraints such as crushing depth, variation, and crushed particle size. The data for this study are chosen from the site of construction in Kangnung during three months ($2004.\;6.\;1\;\sim\;2004.\;8.\;31$). The provided methodology in this paper will be fruitful not only for the selection of crushing machine but also for the aspects of construction period, cost, work efficacy according to the condition from the various sites of construction.

• Advances in concrete construction
• /
• 제8권2호
• /
• pp.91-100
• /
• 2019

In this paper three damaged exterior RC beam-column joints made of recycled aggregate concrete (RAC) were repaired. The aim of the study was to restore back the lost capacity of the beam-column joint to the original state or more. A relatively cheap material locally available galvanized steel welded wire mesh (GSWWM) of grid size 25 mm was used to confine the damaged region and then jacketed with cement mortar. Repaired specimens were also subjected to similar cyclic displacement as those of unrepaired specimens. Seismic parameters such as load carrying capacity, ductility, energy dissipation, stiffness degradation etc. were analyzed. Results show that repaired specimens exhibited better seismic performance and hence the adopted repairing strategies could be considered as satisfactory. These findings would be helpful to the field engineers to adopt a suitable rapid and cost efficient repairing technique for restoring the damaged frame structural joints for post earthquake usage.