• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3542-3547
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• 2015

There is commonly used the full depth excavation method of sewer pipeline maintenance in Korea. This induces couple of technical and social problems like increase of construction cost and time for excavation and backfill, increase of public complains and delay of traffic, and so force. In order to overcome these problems, lots of laboratory tests were carried out for sewer pipeline of maintenance materials with trenchless methods. The testing materials are liquid and hardened polyurethane, and polyurethane CIPP. The lab tests were followed by Korean Standard. There are no side effects, like harmless to the human body and air pollution with stink. Judging from the limited test results, all the items tested were satisfied the KS criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3587-3595
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• 2015

Low-carbon eco-friendly precast concrete (PC) box structure has been recently was developed as an low-cost infrastructure of near-surface transit system. The concrete of PC box was manufactured by industrial byproducts such as ground granulated blast furnace (GGBF) slag, flyash and rapid-cooling electric arc furnace (EAF) oxidizing slag, its mechanical property and durability were estimated in this study. Based on the mechanical and durability tests, it is found that low-carbon eco-friendly concrete shows high initial compressive strength, more than 90% of design strength (35MPa), and high resistance to salt-attack, chemical- attack and freeze-thaw. Therefore, low-carbon eco-friendly PC box concrete technology is expected to contribute to the railway with low environmental impact.

• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.66-73
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• 2002

In this study a new SIS evaluation method based on the reliability analysis has been developed. It evaluates the Safety Integrity Level (SIL) using the Fault Tree Analysis (FTA), and when the SIL falls short of the systems target level, through the reliability analysis and system retrofit, this method will satisfy the aimed SIL. A hazard evaluation was carried out on the 415V Diesel BUS to verify the SIL evaluation method based on the reliability analysis. The availability of the original 415V Diesel BUS was $99.40\%$, which comes under the category of SIL 2. After exchanging the diesel generator and the isolator switch using the developed evaluation method, the availability rose to $99.94\%$, SIL 3. By applying the method presented in this study, not only will it reduce the maintenance cost due to the prevention of accidents and reduction of loss, but also maximize the reliability of the system.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.668-668
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• 2012

제방 비탈면 보호방법 중에서 식생매트를 사용하는 방법은 제방의 보호와 함께 자연친화적이면서 생태계의 보전 측면에서 유리하고 이와 아울러 심미적 효과와 비용의 적절성 등의 요건을 만족하기 때문에 최근 국내 자연형 하천정비에서는 다양한 종류의 식생매트들이 빈번히 사용되고 있다. 하지만 식생매트로 인한 제방의 비탈면 보호 효과에 대해서는 아직까지 정성적으로 분석된 예가 미흡하여 이에 관한 연구가 시급히 요구되고 있는 실정이다. 비탈면을 보호하는 비탈덮기는 생태계와 경관 등의 고려도 중요하지만 그보다 먼저 유수에 의한 파괴가 발생하지 않아야 한다. 따라서 제방의 비탈면 보호 효과가 다른 재료에 비해 상대적으로 취약할 수 밖에 없는 식생매트의 경우 적용범위와 한계를 명확히 하여야 잘못된 적용으로 인한 재해를 막을수 있을 것이다. 근래 들어 지역을 가리지 않는 국지성 폭우로 인한 홍수가 점차로 확대되고 있는 국내 상황을 고려할 때에도 식생매트의 한계와 적용범위의 결정은 매우 중요하다. 본 연구에서는 한국건설기술연구원 안동 하천실험센터 호안블록 시험구간에서 하류 10m 지점에서 시작하는 20m 구간에 두 종류의 식생매트를 교대로 설치하여 각각의 식생매트에 관한 파괴실험을 수행하였다. 두 종류의 식생매트 모두 코코넛 섬유를 원료로 사용하는 제품이며, 식생매트의 파괴 실험은 식생활착 이전의 상황을 재현하여 수행하였다. 이는 통상적으로 식생 활착 이전의 식생매트가 제방 비탈면을 보호하는 효과가 현저히 떨어지는 단점을 가지고 있기 때문에 이에 맞추어 본 실험에서는 식생매트의 자체의 단점과 한계를 파악하는 것을 목적으로 하였다. 실험 결과 두 종류의 식생매트는 모두 침수시 부력으로 인한 부유 현상과 식생매트 틈세 흐름으로 인한 기반층의 세굴 현상을 발견할 수 있었으며, 이러한 상황에서 식생매트를 고정하는 앵커가 매우 중요한 역할을 한다는 것을 발견할 수 있었다. 식생매트가 기반 토층에서 분리되어 파괴가 발생하는 유량조건은 각각 식생매트에 따라 서로 다르게 나타났는데, 이 또한 매트를 고정하는 앵커의 특성 때문인 것으로 판단된다.

• Land and Housing Review
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• v.4 no.3
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• pp.287-294
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• 2013

Energy saving strategy for public housing is given a sizable portion in Land and Housing corporation. From this reason, the consumer's characteristics and energy consciousness of public housing dweller was derived from field survey for compare with sale housing residents characteristics. Utilities fees (e.g. gas and electric) for public housing residents was about 50 percent of sales housing dweller, but real energy consumption was accounting for 70% of sales housing residents in electric consumption. Among the respondents for public housing dweller up to 80 percentile of end-user comment that they have less demanding utilities fees. Given the major energy saving strategies, such as install EMS, make a teaching tool for children, sale housing residents is more proactive approach to participant energy saving strategies than public housing residents.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.979-984
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• 2012

An antiroll-bar assembly is a precision component that is designed to control the rolling of railway cars. It is important for ensuring a safe and comfortable ride. A torsion bar is the main part of the antiroll-bar assembly. Now, this part is classified as a consumable, and it is imported into Korea from France. Therefore, there is a strong need to domestically develop a torsion bar suitable for Korean conditions and to reduce cost and improve quality. In this study, an antiroll bar is developed, and it is analyzed and tested by using a road histogram measured on Korean railroads. This bar shows satisfactory results in a comparison with the imported bar. It has a novel design featuring a ring cover made of SUS steels to prevent the corrosion of the torsion bar. Its safety is examined through CAE analysis and wear tests. It is found that its design does not result in a significant difference in static and fatigue safety. Two different SUS steels were investigated in terms of their wear resistance, and the best one was adopted.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.251-260
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• 2020

Unlike manned aerial vehicles, because an unmanned aerial vehicle (UAV) has a limitation which allows only remote test during flights, it is very important to maintain the high reliability of the vehicle through pre- and post-flight tests. To this end, this paper designed an air vehicle test equipment (AVTE) for UAV which meets the derived hardware and software requirements. Based on this design, the AVTE was implemented in accordance with the actual test scenario. The implemented AVTE has the advantage of reducing the time and cost required for the test of UAV by allowing the operator to perform automatic or manual tests for necessary parts in various situations such as before and after starting engine and pre- and post-flight tests. Furthermore, this study is expected to help with the design and implementation of AVTE for other UAVs.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.357-369
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• 2009

With the development and generalization of internet and information technology, airlines has tried to reduce their business expenses and commissions to travel agencies and enhance service qualities through service automation and simplification, such as internet booking and ticketing, self check-in, in-flight internet and RFID for checked baggage. The statistical techniques conducted for this empirical analysis are frequency analysis, reliability analysis, factor analysis, confirmatory factor analysis and multiple regression analysis. This research has tried to examine factors of airline e-services that influence on recommendation re-purchase intention and satisfaction. Results has found that only on-line reservation and ticketing factor had significant effect for recommendation and re-purchase intention and all e-service factors produced significant effect to total satisfaction. It was also recommend that airlines have to provide easy and more familiar e-service system to their passengers to deliver better services.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.821-829
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• 2000

Over the past decade, the topic of work breakdown structure (WBS) has gained an increasing amount of attention from information technology professionals as an effective tool for managing the complexity of a large-scale information system development project. It is a method for planning and controlling a large-scale information system development. A WBS provides the basis for project organization, cost estimation, task scheduling, and contract management. Based on the authors' practical experience, this paper discusses how to establish a specific WBS and some considerations for developing a well-defined WBS. The model of WBS suggested in this study will provide useful insight and guidelines for establishing the spec-ific WBS for a large-scale information systems development.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1886-1893
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• 2007

More efforts are required to efficiently operate and manage measured data in AMR(Automatic Meter Reading) and manual meter reading that have not become com:[m yet. As customer complaints increase the most appropriate way of finding solutions is precise and reliable metering of data which should be able to maximize customer satisfactions. In this parer, we designed a data mining technique that recommended the reliability of measured data on manual meter reading and a mCRM(Mobile CRM) system that expanded CRM(Customer Relationship Management). We will propose a mCRM in which the system compares the patterns of customer's using data. W the measured data gathered is outside of a similarity measure(maximum and minimum), it enhances the reliability of measured data by managing this fact in mobile for each customers. We will proposed a system where the mCRM provides customers with reliability and efficiency when related enterprises cannot establish AMR because of the burden of extra costs.