• 한국정보통신학회논문지
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• 제12권10호
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• pp.1875-1882
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• 2008

최근 IEEE 802.16 WiMAX에서는 인터넷 기반의 다양한 서비스와 애플리케이션의 빈번한 사용으로 인하여 저비용, 고효율의 특성을 가지는 이동 단말기의 사용이 일반화되고 있다. 이동 단말기의 사용이 일반화되면서 고속 인터넷 서비스의 보안 문제를 해결하기 위한 연구가 IEEE 802.16e 표준을 중심으로 연구되고 있다. 이 논문에서는 IEEE 802.16 WiMAX의 보안 요구사항을 충족하기 위해 IEEE 802.16e 표준에서 제공하는 기본 기능이외에 SS의 인증부하 및 보안공격(reply 공격과 man-in-the-middle 공격)에 안전한 보안 메커니즘을 제안한다. 제안된 메커니즘은 SS와 BS가 생성한 난수와 비밀값을 이용하여 TEK과 데이터 암호에 필요한 키 정보를 교환한다. 또한 SS의 초기 인증정보와 인증서를 이용하여 BS의 추가 인증 과정을 수행하지 않도록 하여 BS의 성능 부하를 줄인다.

• KIEAE Journal
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• 제7권2호
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• pp.71-76
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• 2007

For the many years the children's running noise has caused perpetual frictions between neighbors in apartment houses. For this reason the government established a regulation to reduce the floor impact noise, as a result almost all apartment houses have been enforced to use the floor structure with 210mm thickness concrete slab and 120mm thickness of floor heating system since July 2005. If do not want to apply this kind of system, a system which obtain the certification from the institution appointed by government must be applied. In this reason a lot of construction material companies and construction companies have been trying to develop the system with 180mm thickness concrete slab for the purpose of reducing the cost. To develop the optimized floor system, actual size test building were constructed and the materials related with reducing floor impact noise were composited and tested in the test building. Through this procedure the most effective system was found.

• 대한안전경영과학회지
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• 제16권1호
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• pp.201-206
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• 2014

GCM(Green Chain Management) is being spread by that companies which apply with eco-friendly concept in entire SCM(Supply Chain Management) perspective is being increased for resolving some recent environmental problems. There are reasons that numerous companies focus on GCM. At first various governments began to directly manage components and material contents about various noxious substances. Second, environment problem management in the entire logistics process from procurement of product materials to distribution of product became to be important according to introduction of certification system that evaluate the environmental impact throughout life-cycle of products. Purposes of this paper are 1) to analyze the GCM process whose important is more increasing in the recent logistics environment change, 2) to comprehend places and sources that generate environmental elements like energy consumption and greenhouse gas emissions in elements of logistics function, and 3) to construct integrated GCM system for observing activity of logistics function throughout life-cycle of products.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2262-2269
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• 2010

A recent Tilting train development operation for existing line high speed, already developed "Korean Tilting Train eXpress(bellow TTX)" and that doing demonstration of operation. And TTX are going to commercial service in 2012. They are preparing Environmental Declaration of Product(bellow EDP) for offering environmental impact of TTX to customer. EDP calculated environmental impact of target product's whole life cycle(raw material and manufacturing, distribution, use, end of life) more quantity for that improving environmental impact and then certification them, it is using for that estimate some part of existence of specific pollutants, GHGs, energy consumption and recycling ratio. In this study, 1) analyze the process of getting EDP, 2) satisfy common criteria and each criteria(plan) in the Product Category Rules(bellow PCRs) provided KEITI, 3) according to ISO 14044, implementation of LCA. 4) These results be shown Characterized Impact(bellow CI) about each life cycle stage and six impact categories(ARD, GWP, OD, AD, EU, POC).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.244-249
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• 2011

The potential hazards resulting from a low-velocity impact (bird-strike, tool drop, runway debris, etc.) on aircraft structures, such as engine nacelle or a leading edges, has been a long-term concern to the aircraft industry. Certification authorities require that exposed aircraft components must be tested to prove their capability to withstand low-velocity impact without suffering critical damage. In most of the past research studies unloaded specimens have been used for impact tests, however, in reality it is much more likely that a composite structure is exposed to a certain stress state when it is being impacted, which can have a significant effect on the impact performance. And the radiated impact sound induced by impact is analyzed for the damage detection evaluation. In this study, an investigation was undertaken to evaluate the effect in-plane loading on the impact force and sound of composite laminates numerically.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.107-108
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• 2014

The rural area has aged and depressed for urban area in Korea. Furthermore, the rural house has deteriorated and is vulnerable to disaster which collapse, fire, landslide, and so on. For this matter, it need to an evaluated system for deteriorated level of rural house. The evaluated system has a repairing method and an estimated cost for rural house to offer native in rural area. This study could draw evaluation factor for deteriorated level of rural house as a basic study for the evaluated system. The evaluation factors is compared the Korean housing performance grade indication system, the Korean green building certification criteria, and the Japanese housing performance indication system. As a result, they could eight types. There are a mothproof, an waterproof, a finishing material, an asbestos cement slate of roofing, a mobility right, an opening and closing of doors and windows, an indoor environment.

• 자동차안전학회지
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• 제7권3호
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• pp.19-24
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• 2015

Brake pads are a component of disc brake system of automobile and consist of steel backing plates and friction material facing the disk brake rotor. Due to the repeated sliding forces and torque in vehicle braking, friction performance of brake pads are ensured. Futhermore, the brake pad is one of major tuning components in aftermarket, mechanical characteristics of the brake pad are necessary to evaluate for establishing the certification standards of tuning components. This study had performed the five specimen tests for friction coefficients and wear loss rates according to the SAE test specification. Using the instrumented indentation method, yield strength and tensile strength were measured. Friction coefficients, 0.386 - 0.489, and wear loss rates, 1.0% - 3.7% are obtained. The range of yield strength and tensile strength are 21.4 MPa - 105.3 MPa and 39.5 MPa - 176.4 MPa respectively.

• 항공우주시스템공학회지
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• 제6권2호
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• pp.28-34
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• 2012

Structural integrity evaluation is important item in the aircraft certification. Recently, it is designed for limit load, material weakness about fatigue and corrosion, damage by bird strike in flight to evaluate structural integrity of aircraft. And static/fatigue analysis are performed to secure structural integrity, it was verified by static and fatigue tests. To evaluate the structural integrity of small aircraft tail, structural integrity was calculated by the finite element analysis. In the present study, finite element analysis are performed to pick out load cases in flight occurrence, and secure margin of safety to evaluate structural integrity of KC-100 tail unit. The proprieties of finite element analysis results are compared with the static structure test results. The estimation process of structural integrity for small aircraft tail may help the design.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.104-105
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• 2013

The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. Fireproof spray-application also loses its performance and this performance loss of thr fireproof spray-application is very important because fire resistance of buildings depends on fireproof spray-application. So this study is to develop Acceleration durability test method of Fireproof spray-application, and use the Certification of fire resistant coating system.

• 분석과학
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• 제26권1호
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• pp.91-98
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• 2013

세계적으로 석면에 관한 다양한 연구사례가 발표되고 있는 가운데, 최근 미국을 비롯해 국내 또한 NOA (Naturally Occurring Asbestos)에 대한 관심으로 석면분포 광산 및 주변지역의 지질도 작성, 광산복원, 유해성 평가 등을 실시하고 있다. 본 연구에서는 토양 중 백석면을 분석하는 과정에서 정성, 정량 평가용 표준물질을 개발함으로써 분석결과에 대한 분석기관 및 분석자의 신뢰성 향상과 더불어 광학현미경의 기초자료를 확보고자 한다. 석면분석은 정성분석과 정량분석으로 구분하였으며, 석면정량을 위한 방법은 EPA 600-R-93-116의 점계수법(point counting)으로 총 400지점을 계수하는 방법으로 실시하였다. 제작된 2종에 해당하는 인증표준물질(CRM, Certified Reference Material)을 분산분석과 회귀분석을 이용하여 각각 균질성과 장기 안정성을 확인한 결과 이상이 없음을 확인하였다. 인증표준물질의 인증값은 점계수 결과의 최소값에서 최대값에 이르는 결과를 포함하며 저농도, 1% (범위, 0.25~3.00), 고농도, 4% (범위, 2.25~5.50)로 산출되었다.