• 인지과학
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• 제13권2호
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• pp.1-13
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• 2002

본 논문에서는 표층 언어 표현의 응집성 (coherence)이 과학 텍스트의 이해에 어떤 효과를 주는지에 대해 검토하였다 이 연구는 응집성의 강도가 과학 텍스트 이해의 정도와 관계가 있는 지 검토하고. 텍스트의 이해가 지엽적 응집성과 총체적 응집성의 관점으로 어떻게 설명될 수 있는지, 또는 다른 요인과 어떠한 관계가 있는지 조사하였다. 이해에 대한 응집성 강도의 효과를 알아보기 위하여 원인, 반복, 직시사 (deixis). 정박 (anchoring)등의 응집장치 (cohesive devices)를 이용하여 텍스트의 응집성 강도를 조작하였으며. 이에 대한 오프라인 처리 과제를 실시하였다 실험 결과, 응집성이 강한 텍스트가 보다 용이하게 이해된 것으로 나타났다 단락별로 분석된 회상 및 재인 검사의 결과에서는 응집장치의 종류에 따른 응집성 효과가 선택적으로 나타났다 이는 응집장치의 지엽적 효과가 일관적이지 않다는 것을 의미하는 것으로 보인다. 한편 텍스트의 주제가 얼마나 긴밀하게 연결되었는지 분석한 결과. 주제 연결 (topic continuity)의 긴밀성 정도가 텍스트 이해와 관련되어 있음을 발견하게 되었다 이러한 결과는 텍스트 이해가 지엽적 응집성의 선택적 효과에 의해 구축되는 상향적 (bottom-up) 과정뿐만 아니라. 텍스트 전체를 지배하는 하향적 (top-down) 과정에 의해 촉진됨을 암시한다

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3116-3121
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• 2007

In this paper, the inverse shape design is introduced using the permeable wall boundary condition. Inverse shape design defines the blade shape for the prescribed Mach numbers or pressure distribution on its surface. It calculates the normal mass flux from the difference between the calculated and prescribed pressure at the surface. A new geometry can be achieved after applying the quasi one-dimensional continuity equation from the leading edge to the trailing edge. For validation of this method, two test cases are studied. The first test case of inverse shape design illustrates the cosine bump with a strong shock. After seven geometry modifications, the shock-free bump geometry can be obtained. The second example concerns the redesign of a transonic turbine cascade. The initial isentropic Mach distribution has a peak on the upper surface. The target isentropic Mach number distribution was imposed smoothly. The peak of Mach distribution has disappeared at the final geometry. This proposed inverse design method has proven to be an efficient and robust tool in turbomachinery design fields.

• 한국화재소방학회논문지
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• 제13권4호
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• pp.30-37
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• 1999

본 연구에서는 아트리움 공간에서의 화재성상을 파악하기 위해 실물 실현의 대안으로서 축소 모형 실험을 수행하였다. 연속방정식, 운동량 보존 방정식, 에너지 보존 방정식과 같은 지배 방정식의 차원해석으로부터 추론된 $\pi$변수로부터 축소법칙을 얻었다. 이 축소법칙에 따라 일본의 시반스 아트리움을 1/50로 축소한 모형에서 실험을 수행하였다. 여기서 얻어진결과를 실물 실험 결과와 비교하였다. 더 나아가 이러한 결과들은 레이저 관광을 이용한 가시화 시스템에 의해 가시화 되어졌다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.852-855
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• 2010

Numerical simulations for large scale triaxial tests with large diameter rockfill materials are conducted using distinct element method. For generation of compacted assembly with specific grain size distribution and initial material porosity, the clump logic method and expansion of generated particles are adapted. With micro parameters which are chosen by calibration process, discrete particle modelling of triaxial test in case of other confining stress and cyclic loading condition were conducted. Also numerical simulations of fluid injection into particulate materials were conducted to observe cavity initiation and propagation using distinct element method. The fluid scheme solves the continuity and Navior-Stokes equations numerically, then derives pressure and velocity vectors for fixed grid by considering the existence of particles within the fluid cell.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.394-397
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• 2006

For checking fatigue safety and endurance of precast concrete deck and loop joint system in the steel plate girder composite bridge, the test composite bridge model was made for the fatigue experiment by the wheel load machine. The fatigue tests of 1,000,000 cycles were implemented according to wheel load condition of DB24 rear axle of Korea Highway Design Code. From the test results, the loop joint system for the precast deck has a sufficient flexural capacity. Although a little lower longitudinal continuity capacity is evaluated than general sound cast-in-place RC bridge deck, there is no problem about the safety. The overall fatigue level of safety defined by the code is satisfied.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.21-24
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• 2008

Tests were performed to obtain the flexural capacity of the innovative FRP-Concrete Composite Deck (FCCD) above girders. Test parameters were details of connection parts between FCCD and girder, such as continuity of FRP module, reinforcing ratio of FRP re-bars, and existence of shear connecting plate. As a test result, we found flexural strength of FCCD in the negative zone increases when FRP module is continuous, and reinforcement is increased, and shear connecting plate exists. And the flexural strength of all specimens give enough safety compared to the value needed in Korean highway bridge design code.

• Journal of Positioning, Navigation, and Timing
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• 제12권4호
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• pp.369-377
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• 2023

This paper presents the analysis results of navigation performance of Korea Augmentation Satellite System (KASS) test signals. Performance analysis was performed with Global Positioning System (GPS) and Satellite Based Augmentation System (SBAS) signals received from 7 KASS reference stations. And the performances were analyzed in terms of the signal strength, statistics for each SBAS message, coverage of ionospheric correction, accuracy, integrity, continuity, and availability. In addition, the navigation solutions provided by commercial receiver was analyzed and the performance experienced by general users was presented. Lastly, directions for further improvement of the KASS system were addressed. These performance analysis results can be used to confirm the feasibility of utilizing KASS in user applications.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1652-1656
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• 2022

Fire tests were conducted on cables using fire-retardant paint employed in nuclear power plants that transmit electrical power, control and instrument signals. The failure criteria of various power and control cables coated with fire retardant coating at three different coating thicknesses (~0.5 mm, 1.0 mm & 1.5 mm) were studied under direct flame test using Container Fire Test Facility (CFTF) based on standard tests for bare cables. A direct flame fire test was conducted for 10 min with an LPG ribbon burner rated at ten by fixing the cable samples in a vertical cable track. Inner sheath temperature was measured until ambient conditions were achieved by natural convection. The cables are visually evaluated for damage and the mass loss percentage. Cable functionality is ascertained by checking for electrical continuity for each sample. The thickness of cable coating on fire exposure is also studied by comparing the transient variation of inner sheath temperature along the Cable length. This study also evaluated the adequacy of fire-retardant coating on cables used for safety-critical equipment in nuclear power plants.

• Composites Research
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• 제14권2호
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• pp.8-12
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• 2001

필라멘트 와인딩 공법(filament winding process)은 회전하는 맨드렐에 로빙(roving)형태의 연속섬유를 감는 비교적 간단한 공정이다. 이것은 저장탱크, 화학용 파이프, 그리고 다른 산업에 사용되는 안정적이고 다양한 공법이다. 본 연구에서는 split disk test 치구와 dress disk test 치구에 의한 필라멘트 와인딩 링 시편의 인장강도 값을 실험에서 얻어진 결과와 혼합법칙에 의해 얻어진 이론적인 값을 비교하였다. 이 논문의 목적은 필라멘트 와인딩 구조물의 인장 특성 평가에 대한 적합한 시험법을 제안하고 있는 것이다. dress disk test 치구로 시험한 링 시험편의 인장강도는 split disk test 치구의 모서리 부분에서 발생하는 응력집중 때문에 split disk test의 시험 결과보다 이론적인 인장강도 간에 잘 근절함을 보여준다. 이 실험 결과 시험 치구의 기하학적 형상과 섬유의 연속성, 섬유 장력 그리고 시험편의 응력 집중에 영향은 받음을 알 수 있었다.

• 한국항공운항학회지
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• 제24권1호
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• pp.10-15
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• 2016

In this study, The code-carrier divergence test was applied to GPS measurements, and the results were compared and analyzed. The GPS data used for the threshold determination were obtained from Global Navigation Satellite System permanent stations built by the Korea Aerospace Research Institute. At each permanent station, identical dual-frequency receiver and choke ring antenna with radome are installed. The analysis method, root mean square values were compared and analyzed for each permanent station and satellite. As a result, the root mean square value generally decreased as the satellite elevation angle increased although the trend was gentle. Threshold were finally selected based on the average and standard deviation of root mean square for each permanent station. For improving of availability and continuity in real-time operation when the threshold is over the limits, Code-Carrier divergence test values are initialized.