• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권6호
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• pp.2139-2151
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• 2014

Embedded system testing, especially long-term reliability testing, of flash memory solutions such as embedded multi-media card, secure digital card and solid-state drive involves strategic decision making related to test sample size to achieve high test coverage. The test sample size is the number of flash memory devices used in a test. Earlier, there were physical limitations on the testing period and the number of test devices that could be used. Hence, decisions regarding the sample size depended on the experience of human testers owing to the absence of well-defined standards. Moreover, a lack of understanding of the importance of the sample size resulted in field defects due to unexpected user scenarios. In worst cases, users finally detected these defects after several years. In this paper, we propose that a large number of potential field defects can be detected if an adequately large test sample size is used to target weak features during long-term reliability testing of flash memory solutions. In general, a larger test sample size yields better results. However, owing to the limited availability of physical resources, there is a limit on the test sample size that can be used. In this paper, we address this problem by proposing a self-adaptive reliability testing scheme to decide the sample size for effective long-term reliability testing.

• 한국식물병리학회지
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• 제1권2호
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• pp.115-121
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• 1985

벼 흰빛잎마름병에 대한 새로운 포장 저항성 검정법을 모색하기 위하여 검정 식물체 접종법과 인접 식물체 접종법을 비교 검토하였다. 새로운 검정법인 검정 식물체 접종법에서는 포장 저항성 검정 식물체를 전엽접종한 발병엽으로부터 새로 출엽된 잎에 이차전염된 발병 엽면적율을 측정하였다. 검정 식물체 접종으로 검정된 포장 저항성 정도는 인접 식물체 접종 결과와 높은 상관이 인정되었으나 포장 저항성 정도는 검정 식물체 접종법에서 명확히 구분되었다. 공시한 33품종 중에서는 밀양 42호, 삼강벼, 태백벼, 한강찰벼, 섬진벼, 70 X-46, 중국 45호 등이 강한 포장 저항성을 보였다. 새로운 포장 저항성 검정법은 품종의 질적 저항성 및 포장 저항성을 동시에 검정할 수 있을 뿐만 아니라 다른 검정법에 비하여 노력과 포장 면적이 적게 들기 때문에 유용한 검정법으로 이용될 수 있을 것으로 생각된다.

• Smart Structures and Systems
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• 제12권6호
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• pp.661-678
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• 2013

In this paper, a wireless sensing system for structural field evaluation and rating of bridges is presented. The system uses a wireless platform integrated with traditional analogue sensors including strain gages and accelerometers along with the operating software. A wireless vehicle position indicator is developed using a tri-axial accelerometer node that is mounted on the test vehicle, and was used for identifying the moving truck position during load testing. The developed software is capable of calculating the theoretical bridge rating factors based on AASHTO Load and Resistance Factor Rating specifications, and automatically produces the field adjustment factor through load testing data. The sensing system along with its application in bridge deck rating was successfully demonstrated on the Evansville Bridge in West Virginia. A finite element model was conducted for the test bridge, and was used to calculate the load distribution factors of the bridge deck after verifying its results using field data. A confirmation field test was conducted on the same bridge and its results varied by only 3% from the first test. The proposed wireless sensing system proved to be a reliable tool that overcomes multiple drawbacks of conventional wired sensing platforms designed for structural load evaluation of bridges.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1058-1064
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• 2004

As one of reinforcing methods for soft roadbed, the problems that mud-pumping and settlement occurred by soft roadbed, were investigated, evaluated and analyzed through installing relatively economical and efficient geosynthetics on the selected track-bed for testing. Mock-heang to Dong-ryang on the filed resting sections in the Chung-buk lines were selected as investigating the state of track and prepared field after selecting three of 1,700 spots which often make mud-pumping and requiting maintenance for that. Long curved line radiuses(R) of Mock-heang to Dong-ryang are 500m that were installed with 4 types of geosynthetics layers and one ballast layer. Installed testing cross-section is 200m totally with 40 m between places. Strength or prepared roadbed was measured to investigate the state of roadbed and track with constructing(installing) field testing sections and physical properties of roadbed soils were evaluated and analyzed. Also, mud-pumping, settlement of elastic or plastic sleeper, failure or track, wheel-loads, transverse and earth pressures were measured after installing field testing sections.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권12호
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• pp.626-633
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• 2004

In this paper, we present a time domain combined field integral equation (TD-CFIE) formulation to analyze the transient electromagnetic response from three-dimensional dielectric objects. The solution method in this paper is based on the method of moments (MoM) that involves separate spatial and temporal testing procedures. A set of the RWG (Rao, Wilton, Glisson) functions Is used for spatial expansion of the equivalent electric and magnetic current densities and a combination of RWG and its orthogonal component is used as spatial testing. We also investigate spatial testing procedures for the TD-CFIE to select the proper testing functions that are derived from the Laguerre polynomials. These basis functions are also used for temporal testing. Use of this temporal expansion function characterizing the time variable enables one to handle the time derivative terms in the integral equation and decouples the space-time continuum in an analytic fashion. Numerical results computed by the proposed formulation are presented and compared with the solutions of the frequency domain combined field integral equation (FD-CFIE).

• Steel and Composite Structures
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• 제46권4호
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• pp.485-495
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• 2023

Bending static and stress investigation of a microplate of piezoelectric/piezomagnetic material subjected to combined multifield loading. Shear deformable as well as thickness stretched model is used for derivation of the kinematic relations. Multi field governing equations are derived analytically through principle of virtual work. the results are analytically obtained analytically including magnetic/electric potentials, displacement and stress components with variation in multifield loading parameters.

• 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.

• Progress in Superconductivity
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• 제8권2호
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• pp.152-157
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• 2007

Uniaxial square Helmholtz coils for testing SQUID sensors were designed and their field distributions were calculated. Optimum parameters for maximizing the uniform region in the Helmholtz mode were obtained for different uniformity tolerances. The coil system consists of 2 pairs of identical square loops, a Helmholtz pair for generating uniform fields and the other for the 2nd-order gradient fields in combination with the Helmholtz pair. Full expressions of the axial component of the field were calculated by using Biot-Savart's law. To understand the behavior of the field near the coil center, analytical expressions were obtained up to the 4th-order in the midplane and along the coil axis. The Helmholtz condition for generating uniform fields was calculated to be $d/{\alpha}=0.544505643$, where 2d is the inter-coil distance and $2{\alpha}$ is the side length of the coil square. Maximized uniform range can be obtained for a given nonuniformity tolerance by choosing $d/{\alpha}$ slightly lower than the Helmholtz condition. The pure second-order gradient field can be generated by subtracting the Helmholtz field from the field of the 2nd pair with equal magnitudes of the center fields of the two pairs. The coil system is useful for testing balance and sensitivity of SQUID gradiometers.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.227-230
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• 2009

In this paper, the results of field testing of high-speed power line in-home networking in Korea are reported. When multiple networks share a common channel, they can interfere destructively and reduce system capacity. This is major problem in-home power line communications, especially in MDU deployments. The effects of neighboring network interference in power line communications are reported.

• 전자공학회논문지
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• 제53권11호
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• pp.130-138
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• 2016

본 논문은 무기체계의 오류를 검증할 때 필요한 실시간 시스템 병렬시험 기법에 대해서 제안한다. 이전에 국방분야에서 사용되는 야전시험장비는 무기체계를 순차적으로 검증하는 방식을 사용하였다. 오류를 순차적으로 검증하는 방식은 내부유닛간의 상호 간섭에 의한 부분의 오류검증은 할 수 없었다. 이러한 이유로 인해 본 논문에는 기존에 무기체계 오류 검증 시 사용되는 순차적 시험기법이 아닌 임베디드 장치를 이용한 실시간 시스템 병렬시험 기법을 제안한다. 임베디드 모듈이 탑재된 스위칭 제어카드는 병렬시험을 수행하고 그 결과를 사용자의 제어장치로 전달한다. 이러한 방식은 기존의 방식에 비해 좀 더 정확하게 무기체계 내부의 상호 간섭에 대한 오류 검증을 할 수 있다.