• 복합신소재구조학회 논문집
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• 제1권1호
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• pp.34-45
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• 2010

This paper describes the design, manufacturing process, testing, application, and assessment of capacity-ratings of the first all advanced composites bridge on a public highway system. In order to verify the bridge design prior to the field application, a sub-scale bridge superstructure was built and tested in the laboratory. The field load test results were compared with those of the finite element analysis for the verification of validity. To investigate its in-service performance, field load testing and visual inspections were conducted under an actual service environment. The paper includes the presentation and discussion for advanced composites bridge capacity rating based on the stress modification coefficients obtained from the test results. The test result indicates that the advanced composites bridge has no structural problems and is structurally performing well in-service as expected. Since these composite materials are new to bridge applications, reliable data is not available for their in-service performance. The results may provide a baseline data for future field advanced composites bridge capacity rating assessments and also serve as part of a long-term performance of advanced composites bridge.

• Wind and Structures
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• 제14권3호
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• pp.253-283
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• 2011

This paper presents the field measurement results of wind effects on a super-tall building (CITIC Plaza, 391 m high) located in Guangzhou. The field data such as wind speed, wind direction and acceleration responses were simultaneously and continuously recorded from the tall building by a wind and vibration monitoring system during two typhoons. The typhoon-generated wind characteristics including turbulence intensity, gust factor, peak factor, turbulence integral length scale and power spectral density of fluctuating wind speed were presented and discussed. The dynamic characteristics of the tall building were determined based on the field measurements and compared with those calculated from a 3D finite element model of the building. The measured natural frequencies of the two fundamental sway modes of the building were found to be larger than those calculated. The damping ratios of the building were evaluated by the random decrement technique, which demonstrated amplitude-dependent characteristics. The field measured acceleration responses were compared with wind tunnel test results, which were found to be consistent with the model test data. Finally, the serviceability performance of the super-tall building was assessed based on the field measurement results.

• 한국자원식물학회지
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• 제10권2호
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• pp.128-134
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• 1997

This study was conducted to test on the resistance of varieties bred by crossing with Asominori to bacterial leaf blight. Nakdongbyeo and Dongjinbyeo which were susceptible to HB 9011, 8 resistant varieties including Ilmibyeo derived from Asominori and Asominori, Hwangok, 13 varieties including Chukoku 45 which were resistance to HB 9011, HB 9022 and HB 9033 were used to screen their res ponce depending on the various screening methods such as the true resistance, the secondary infection resistance and the disease common field test methods, and the results are as follows: Among 13 varieties tested, 11 varieties including llmibyeo showed tme resistance to HB 9011. Less than 1.0cm of disease lesion were developed on these varieties. Disease lesion was not developed on most of the Asominori lines including Daechongbyeo against IIB9011 and 1lmibyeo was also resistance to HB 9011, on this variety disease lesion area rate was 1.2%, and 7 varieties including Hwajinbyeo showed field resistance to HB 9022. Disease lesion area rate were 19.6% on Nakdongbyeo. 15.6% on Dongjinbyeo, from 3.0% to 2.4% on Asominori lines, and 0.5% on the Asominori when screened at disease common area. Disease was not developed on Keumnambyeo. Significant correlation coefficiences were found between the results from the test methods of the true resistance, the field resistance ancl the field resistance at disease common field tests on Asominori lines, but in some cases, even the varieties on which disease lesions developed, showed field resistance to HB 9022 and HB 9033.

• International Journal of Railway
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• 제1권2호
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• pp.64-71
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• 2008

The quality of track-bed fills of railways has been controlled by field measurements of density $({\gamma}_d)$ and the results of plate-load tests. The control measures are compatible with the design procedures whose design parameter is $k_{30}$ for both ordinary-speed railways and high-speed railways. However, one of fatal flaws of the design procedures that there are no simple laboratory measurement procedures for the design parameters ($k_{30}$ or, $E_{v2}$ and $E_{v2}/E_{v1}$) in design stage. A new quality control procedure, in parallel with the advent of the new design procedure, is being proposed. This procedure is based upon P-wave velocity involving consistently the evaluation of design parameters in design stage and the field measurements during construction. The Key concept of the procedure is that the target value for field compaction control is the P-wave velocity determined at OMC using modified compaction test, and direct-arrival method is used for the field measurements during construction. The procedure was verified at a test site and the p-wave velocity turned out to be an excellent control measure. The specifications for the control also include field compaction water content of OMC${\pm}$2% as well as the p-wave velocity.

• 한국전자파학회논문지
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• 제30권2호
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• pp.160-168
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• 2019

본 논문에서는 근전계 빔 집속(near-field beam focusing: NFBF) 시험을 활용한 평면위상배열레이다 시스템의 성능 검증 방안을 제시하고 결과의 유효성을 확인하였다. 제시한 시험 기법은 안테나 개구면 크기 두 배 거리의 근전계 영역에서 레이다 시스템을 검증하는 방안으로 야외가 아닌 전자파 무반향실 내에서 원전계 성능 시험과 동일하게 레이다 시스템을 검증할 수 있었다. 이를 위해 근전계 에너지를 사용한 빔 집속 시험의 시험 구성도 및 검증 절차에 대하여 기술하였다. 또한 빔 조향된 근전계 빔 집속 시험에 대한 수학적인 검증을 통해 개별채널의 추가적인 위상 보상값을 수치화하였다. 이론적인 검증에 기반하여 실제 근전계 빔 집속 시험을 수행하였고 이상적인 결과와의 비교를 통해 시험 방법의 유효성을 확인하였다.

• 한국정보전자통신기술학회논문지
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• 제11권1호
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• pp.1-11
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• 2018

본 논문은 다양한 환경에서 디지털라디오의 방식별 수신 특징을 확인하고 비교할 수 있는 필드테스트 결과를 도출하였다. In-band 방식으로는 HD Radio와 DRM+를 고려하였으며, out-of-band 방식으로는 DAB/DAB+/T-DMB 방식을 고려하였다. 디지털 라디오의 필드테스트를 위하여 국내의 적합한 지역을 선정하여 송수신기 test bed를 구축하였고, multipath가 많고 적은 19개의 다양한 test point를 선정하여 실내외 수신테스트를 진행하였다. 또한 수신환경 측정 시 수신 가능 여부뿐만 아니라 ATT 마진을 적용하여 최소 수신가능 레벨도 도출하였다. 다양한 분석을 통한 필드 테스트 결과는 소비자들에게 원활한 수신환경을 보장하기 위한 디지털 라디오의 방식 결정의 기준이 될 수 있다.

• 한국소음진동공학회논문집
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• 제16권7호
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• pp.704-711
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• 2006

Vibration test on MAST(multi axial simulation table) system has several advantage over one-axial vibration test that could simulate 6-DOF, 3-axial translation and 3-axial moment, at the same time. Since field vibration motion can be fully represented with 6-DOF, multi-axial vibration test on vehicle component is widely conducted in technical leading companies to make sure its fatigue performance in vibration environment. On the way to fulfill the process, editing technique of obtained field data is key issue to success a reliable vibration testing with MAST system. Since the original signals are not only too large to fulfill it directly, but all of the measured data is not guarantee its convergency on generating its driving files, editing technique of the original signals are highly required to make some events that should meet the equal fatigue damage on the target component In this paper, key technique on editing a field data feasible for MAST system is described based on energy method in vibration fatigue. To explain its technique explicitly, author first introduced a process on field data acquisition of two vehicle component and then, representing events are produced to keep up with the editing strategy about a energy method. In the final chapter, a time information regarding a vibration test on MAST system is derived from the energy data which is critical information to perform a vibration test.

• 터널과지하공간
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• 제16권5호
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• pp.405-412
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• 2006

지하대공간 건설에 있어서 숏크리트는 가장 중요한 지보재임은 주지의 사실이다. 숏크리트의 강도는 현장 배합 및 타설 조건에 따라 실험실 조건의 숏크리트와는 큰 차이를 보이는 것이 일반적이다. 구조부재인 일반 콘크리트와 달리 숏크리트의 초기강도는 지하공간의 초기 안정화에 매우 중요하다. 그러나, 숏크리트 초기강도의 측정은 적절한 현장강도시험방법의 부재로 인하여 잘 관리되지 않은 실정이다. 따라서, 현장에서 숏크리트 초기강도를 효과적으로 측정할 수 있는 방법이 요구되고 있는 실정이다. 본 논문에서는 핀관입시험법 및 점하중강도시험법의 현장 숏크리트 초기강도 측정에 대한 적합성을 검토하였다. 이를 위해 다양한 양생강도에 따른 일축압축시험, 핀관입시험, 점하중시험을 수행하여 일축압축강도에 대한 신뢰성 높은 핀관입깊이와 점하중 지수의 상관관계식을 도출하였다.

• 대한기계학회논문집A
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• 제22권2호
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• pp.278-288
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• 1998

An efficient and useful method to improve the local stress field in a displacement-formulated finite element solution has been proposed using the theory of conjugate approximations for a stress field and the Loubignac's iterative method for a displacement field. Validity of the proposed method has been tested through three test examples, to improve the stress field and displacement field in the whole domain and the local regions. As a result of analysis on the test examples, it is found that the stress field in the local regions are approximated to those in the whole domain within a few iterations which have satisfied the original finite element equilibrium equation. In addition, it is found that the local stress field are by far better approximated to the exact stress field than the displacement-based stress field with the reduction of the finite-element mesh-size.

• Advances in Traditional Medicine
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• 제6권3호
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• pp.174-178
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• 2006

The ethanolic extract of Leucas aspera root was studied for its effect on the central nervous system (CNS) using pentobarbitone induced sleeping time test, the open field test and the hole cross test in Swiss albino mice. The present investigation revealed that the extract at the doses of 250 and 500 mg/kg, significantly prolonged the pentobarbitone induced sleeping time in mice though the onset of sleep was delayed as compared to control. In open field test the depressing effect was prominent from the second observation period (30 min) and persisted throughout the entire experimental period (240 min). In the hole cross test, the depressing effect was observed significant from the third observation period (60 min) and persisted up to the seventh observation period (240 min) except at fourth observation (90 min) for 250 mg dose group and depressing effect was significant from second observation (30 min) up to seventh observation period (240 min) for 500 mg dose group. These results support the finding that Leucas aspera root may contain biologically active constituent(s) having CNS activity.