• Tunnel and Underground Space
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• v.33 no.5
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• pp.348-372
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• 2023

In relation to the high-level radioactive waste disposal project in deep fractured rock aquifer environments, it is essential to evaluate hydrogeological characteristics for evaluating the suitability of the site and operational stability. Such subsurface hydrogeological data is obtained through in-situ tests using boreholes excavated at the target site. The accuracy and reliability of the investigation results are directly related to the selection of appropriate test methods, the performance of the investigation system, standardization of the investigation procedure. In this report, we introduce the detailed procedures for the representative test method, the constant pressure injection test (CPIT), which is used to determine the key hydrogeological parameters of the subsurface fractured rock aquifer, namely hydraulic conductivity and storativity. This report further refines the standard test method suggested by the KSRM in 2022 and includes practical field application case conducted in volcanic rock aquifers where this investigation procedure has been applied.

• Journal of the Korea Society for Simulation
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• v.28 no.3
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• pp.41-48
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• 2019

In modern-war campaign, precision-guided missiles are dominantly used to minimize the collateral damage. Imaging infrared seekers are widely applied for the precise guidance. Due to the high cost of the infrared detector, the cost for the one-shot weapon's test is a burden for the development. To reduce the test cost, a simulation method including imagery tracking is required, which is so-called integrated-flight simulation(IFS). The synthetic image generation(SIG)-based simulation method is typically used, which however cannot represent various environmental and target conditions. In this paper, a new IFS method is proposed using on-sight measured image to overcome the limitations of the SIG-based IFS(SIIFS). The target image acquired at the launching sight has been used only for checking the performance criteria of the image tracker and has not been tried for IFS since it has low resolution and little information. The study described in this paper, however, shows that the on-sight image-based IFS can predict the pre- and mid-course flight performance quite similarly and is very useful for the flight test analysis.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.243-254
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• 2019

In this study, problems of the waterproofing methods in which water leakage occurs in the upper slab of the underground parking lot of apartment houses and the requirements considering the characteristics of the upper slab, and selected the appropriate performance(proposal) for the composite polyurea process are reviewed. As a result of the study, it is necessary to review performance such as responsiveness to upper slab of the multi-unit underground parking lot that is comprised of (1) crack and behavior responsiveness, (2) surface integrity, (3) vertical watertight stability, (4) pressure layer construction, (5) impact and pressure response and (6) vehicle moving load. As a result of evaluating 5 items corresponding to the requirements for the soft and hard complex polyurea, all of them were found to meet the conditions, and each materials were improved by compounding the materials that had problems when applying a single-ply method, thereby clarifying the advantages and disadvantages of the material property. However, in order to apply to the actual site, additional evaluation on site applicability such as mock-up evaluation should be conducted, and subsequent studies on the applicability of the market through review of economic feasibility and maintenance is required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.597-602
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• 2021

Even in the era of the 4th industrial revolution, the prevention of industrial accidents is still an important issue in industrial sites. In solving the problem of industrial safety, a product can be difficult to market if there is a lack of standard or method for a reliable performance evaluation. The purpose of this study was to develop and evaluate a test method for a wearable airbag product for protecting the body from falls that was newly developed to respond to fall accidents in industrial sites. As a research method, reliable evaluation standards were developed and applied through four stages of the evaluation and development process (Step 1: Product review, Step 2: Data research, Step 3: Expert meeting, Step 4: Drawing evaluation standard). In addition, the impact force was evaluated according to the developed evaluation standard. The fall impact force obtained through the evaluation showed a reduction effect of approximately 96% compared to the existing impact force. Therefore, the fall impact force was reduced significantly when the airbag was applied. This will enable new convergence products to be launched on the market and produce an environment where industrial workers can work safely.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.197-208
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• 1999

Recently, risk management is a very important issue in many industrial applications. This paper describes a general structure for risk management and suggests a new risk assessment methodology. In risk management applications of financial or insurance industries, there are many methodologies developed for practical use. However, areas for improvement exist to facilitate the application of the methods. Two major risk assessment methodologies have been developed and widely applied in system engineering. One is in its original development application from aerospace and defense industry, and the other was developed in applied software engineering. In a large and complicated system development application, an effective risk management can reduce total development cost as well as uncertainty in achieving project goals of schedule and performance.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.25-32
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• 2013

This study has been conducted in order to propose Eco-friendly and High functional waterproofing technology available for structure by verifying application and performance of water proofing material(s) in purpose of making effective use of reclaimed rubber. As s result of 12 months evaluation, stable performance for water pressure and lateral pressure of $0.3N/mm^2$ were confirmed. Also, as the time elapsed, the amount of water absorption and adhesion performance showed only a slight difference(+0.05g, $-0.1Nmm^2$) as well, which in turn confirmed that waterproofing performance remains stable. Studies show that it is expected to expand recycling technology of natural rubber by applying reclaimed rubber on construction waterproofing field, and to hold a technical superiority by using eco-friendly material in construction waterproofing market throughout active application of these types of research.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.86-86
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• 2011

토목 기술의 발달로 장대교량이 증가함에 따라 교면 포장도 더 심각한 진동 및 충격, 기상조건에 노출되게 된다. 교면 포장은 차량의 주행의 편리성뿐 아니라 교량 구조물을 보호해야 하는 역할도 함께 수행하기 때문에 일반 토공부의 포장과 다른 성능을 필요로 한다. 교면 포장의 특수함을 감안하여 교면 포장의 품질을 평가하고, 설계와 적용시 반영 한다면 교량의 내구 연한 및 시공, 유지관리 비용을 절감 할 수 있을 것이다. 본 논문에서는 교면 포장에 요구되는 성능을 조사하고, 교면 포장 특히, 장대 교량 적용시 교면 포장의 성능 평가를 위한 평가 방법을 고찰하였다. 교면 포장의 가장 큰 구조적 특징은 교량의 진동과 휨에 의해 포장이 받게 되는 휨응력이다. 특히 교량의 장경간화에 따라 더 큰 진동과 변형을 경험하게 되는 교면 포장은 그에 따른 충분한 휨 추종성과 피로 저항성을 확보하여야 한다. 기존 토공부 포장에서는 실험이 간단한 원통형 공시체를 이용한 간접인장강도 모드의 실험으로 피로 성능을 평가하였으나, 교면 포장은 실제 거동 특성과 유사한 빔 피로 시험 모드가 보다 신뢰성이 높을 것으로 판단된다. 빔 피로시험 모드로는 3점, 4점, 5점 휨 피로 시험 모드가 있으며, 각각의 모드는 지지점의 개수, 재하점의 개수에 따라 다른 거동 특성을 평가 할 수 있다. 최근 개발된 5점 휨 시험의 경우 교량에서 발생하는 부(-)모멘트를 모사할 수 있어 보다 현실적인 검증이 가능할 것으로 예상된다. 이 외에도 실제 크기 모형을 이용하여 윤하중을 가하는 Full-scale 모델의 경우 비용과 시간이 많이 소요되는 단점이 있으나 가장 신뢰성이 높은 방법이라고 할 수 있다. 교면 포장은 교량구조부로 수분이 침투되는 것을 막아주는 역할을 하여야 하며, 특히 해상 교량의 경우의 염분과 겨울철 사용되는 제빙화학제는 콘크리트의 열화와 강구조물의 부식을 발생시키므로 교면 포장의 방수 성능 검토는 매우 중요한 역할을 한다. 일반 토공부 포장과 달리 교면 포장은 하부층이 대기에 노출되어 있기 때문에 겨울철에 더 낮은 온도로 포장체의 온도가 내려가게 되고, 온도가 떨어진 포장층은 스티프니스가 증감함에 따라 저온 균열의 발생확율이 높아지며, 휨추종성도 나빠질 가능성이 높다. 따라서 저온에서의 균열 저항성 및 스티프니스를 평가하는 것은 교면 포장 재료의 중요한 인자 중 하나이다. 포장과 포장 하부층의 접착은 포장층의 일체화된 거동을 할 수 있게 하기 때문에 내구성 향상에 중요하다. 특히 교량과 같이 진동과 변형이 많은 경우에 있어 포장 접착층의 성능은 포장과 교량 구조물의 파손에 더 큰 영향을 미치게 된다. 접착성능은 실내에서의 직접인장모드와 전단접착강도 시험 모드의 실험이 있으며, 현장에서 측정하는 Pull-off 실험 등이 있다. 최근에 교통량과 중차량의 증가와 더불어 교량이 장경간화 되어 가면서 평가방법과 기준을 과거보다 엄격하게 할 필요성이 있다. 하지만 현실은 교면포장에 대한 시방규정이 모호하기 때문에 본 논문에서 제시한 국내외의 다양한 평가방법을 통해 적절한 교면포장의 성능을 평가하고 교면포장의 거동특성에 대한 이해를 함으로써 보다 발전된 교량기술을 확보할 수 있을 것이다.

• Journal of the Korea Institute of Building Construction
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• v.12 no.1
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• pp.1-9
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• 2012

This study aims to propose a performance metric for the application of a horizontal air-exhausting system to be used for the reduction of vapor and/or moisture that exists in the waterproof layer, by evaluating the physical properties. For this reason, tests in accordance with current standards were carried out, and the results were examined. Finally, a proposal was established for a general performance metric that could be applied as fundamental data based on the user's judgment. This has some limitations, in that the object is existing merchandise, however it should be useful for application in the construction field. In the future, analysis of a wider area, including workability, should be added in the phase of field application.

• Journal of the Korea Concrete Institute
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• v.20 no.3
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• pp.335-343
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• 2008

In order to improve the workability in erecting Precast Concrete (PC) members and enhance the seismic resistance capacity of the joints in PC moment frames, a new PC column and its construction process are introduced in this paper. This column is manufactured by centrifugal force in keeping the hollow tube inside; the hollow is little bit wide and the grout can be poured from top to bottom after erection at site so that more compact grouting is possible in horizontal joint. The repeated cyclic loading test for four full scaled specimens was conducted to evaluate the seismic resistance capacity of the joint designed by the proposed system. For the continuity of main reinforcements in column, two connecting methods are used in designing specimens; one is to use mechanical connector and other is lab splice. From the cyclic lateral loading test, it was found that the seismic capacity of the developed PC column joint is comparable to that of monolithic joint.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1897-1899
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• 2003

본 논문에서는 Barrier coupler type UHF 센서의 현장적용 및 감도개선을 위해 외부잡음의 차폐방법과 광대역 안테나를 Barrier coupler type UHF센서에 적용시켜 센서의 성능을 개선시켰다. GIS 내부에서 발생하는 부분방전 신호를 검출하기 위하여 UHF대역(0.3${\sim}$3GHz)의 전자파 신호의 검출이 가능한 광대역 Rectangular 패치 안테나를 barrier coupler type UHF 센서에 적응 설계하였으며, Rectangular patch antenna를 배열(array) 했을 때의 특성들을 비교하였다. 이론 위해 상용화된 EM Simulator를 이용하여 센서의 방향성과 감도 특성을 검토하여 설계 및 제작하였다. 개발된 센서의 실제 특성을 분석하기 위해서 network analyzer로 센서의 특성을 분석하였고, 실규모의 GIS 챔버를 사용하여 다양한 결함에 대한 센서의 감도와 특성을 평가하였다. 본 연구의 결과로서 제작된 barrier coupler type UHF센서가 가스절연기기(GIS)의 부 부방전 신호를 검출할수 있음을 입증하였고, 광대역 외장형센서의 경우 patch antenna의 구조에 크게 상관하지 않음을 알 수 있었다. 향후에는 GIS 내장형 센서와 비교 연구론 통해 barrier coupler type 센서의 성능을 개선하고자 한다.