• 한국항행학회논문지
• /
• 제24권4호
• /
• pp.251-260
• /
• 2020

무인항공기는 일반항공기와 달리 비행 중에는 원격 점검만 가능한 한계가 있기에 비행 전, 후 점검을 통한 비행체의 고신뢰성을 유지하는 것은 매우 중요하다. 이를 위해, 본 논문에서는 무인항공기 점검을 위한 비행체점검장비의 하드웨어 및 소프트웨어 요구사항을 도출하고 도출된 요구사항을 만족할 수 있도록 설계하였다. 이 설계를 바탕으로 실제 점검 시나리오에 맞춰 비행체점검장비를 구현하였다. 구현한 비행체점검장비는 총 3단계에 걸친 기능검증을 통해 비행 전·후, 시동 전·후와 같은 다양한 상황에서 자동점검 또는 운용자가 필요한 부분만 선택하여 수동점검을 할 수 있어 비행체 점검에 필요한 시간과 비용을 줄일 수 있다는 장점을 가진다. 또한 본 연구의 내용은 다른 무인항공기를 위한 비행체점검장비 설계 및 구현에도 많은 참고와 도움을 줄 수 있을 것으로 기대된다.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2002년도 춘계 학술발표회 논문집
• /
• pp.250-257
• /
• 2002

Pseudo dynamic test is an on-line computer control method to achieve the realism of shaking table test with the economy and versatility of the conventional quasi-static approach Pseudo dynamic tests of six full-size RC bridge piers have been carried out to investigate their seismic performance. For the purpose of precise evaluation, the experimental investigation was conducted to study the seismic performance of the real size specimen, which is constructed for highway bridge piers in Korean peninsula. Since it is believed that Korea belongs to the moderate seismicity region, five test specimens were designed in accordance with limited ductility design concept. Another one test specimen was nonseismically designed according to a conventional code. Important test parameters were transverse reinforcement and lap splicing. Lap splicing was frequently used in the plastic hinge region of many bridge columns. Furthermore, the seismic design code is not present about lap splice in Korean Roadway Bridge Design Code. The results show that specimens designed according to the limited ductility design concept exhibit higher seismic resistance. Specimens with longitudinal steel lap splice in the plastic hinge region appeared to significantly fail at low ductility level.

• International Journal of Reliability and Applications
• /
• 제6권1호
• /
• pp.31-39
• /
• 2005

An economic life test sampling plan for products with exponential lifetime distribution is developed. To reduce test time, a test plan with curtailed Type II censoring is considered. A cost model is constructed which involves three cost components; test cost, accept cost, and reject cost. Determination of optimal plan minimizing the expected average cost per lot is discussed with a constraint related to consumer's risk. Some numerical examples are provided.

• 한국자동차공학회논문집
• /
• 제23권1호
• /
• pp.122-129
• /
• 2015

Excessive overheating to a manual transmission clutch system under operating conditions can be considered the main reason of its performance degradation. The clutch system has to be ensured with its service life by showing that it passes the extreme tests called anti-fade test and hill start test in a certain design step. In general, design feedbacks from these kinds of the experiments are adapted to the system to enhance its performance. However, it usually takes much time and costs a lot due to the repetition of the tests. In this research, a process to calculate temperature of the clutch system was developed to determine whether the design can be passed the anti-fade test and hill start test in the design phase. The process incorporates many CAE techniques such as heat transfer analysis using 1D dynamic simulation method, system dynamics, CFD and parametric optimization. CFD is utilized to analyze 3-dimensional heat transfer of the clutch system and fluid dynamics of air in the clutch housing. The process was applied for the clutch systems in several vehicle models. The results was compared with those of the experiment. The applicability of the developed process was verified by comparing the predicted results with experimental results.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1309-1313
• /
• 2008

This paper suggests an example of modification of the durability test specifications of electronic control unit for an automotive system in phase of design validation. The basic concept to redefine the specifications of durability test is based on the Arrhenius relationship for accelerated temperature test and the modified Coffin-Manson model for temperature cycle test. The ambient temperature of the powered-event durability test is increased to reduce the required test time of the current specification. Furthermore, the holding time between the events to cool down the temperature of the components is shortened and the resultant temperature rise affects the durability of the components. Thus, the acceleration factor due to the increased temperature range of temperature cycle is also estimated by the modified Coffin-Manson model.

• 대한전자공학회논문지SD
• /
• 제44권11호
• /
• pp.65-73
• /
• 2007

본 논문에서는 저비용 SoC 테스트를 위한 테스트 설계 기술에 대해서 다룬다. IEEE 1500 랩드 코어를 SoC TAP (Test Access Port) 을 통하여 스캔 테스트를 수행하는 방법을 제시하고, 지연고장 테스트를 위한 테스트 클럭 생성회로를 설계한다. TAP의 신호만을 이용하여 SoC 테스트를 수행함으로써 테스트 핀 수를 줄일 수 있고, SoC 내부의 회로를 사용하여 지연고장 테스트를 수행함으로써 저가의 테스트 장비를 사용할 수 있다. 실험을 통하여 제시한 방식의 효율성을 평가하고, 서로 다른 주파수의 클럭을 사용하는 여러 코어의 지연고장 테스트를 동시에 수행 할 수 있음을 확인한다.

• 전자공학회논문지C
• /
• 제34C권9호
• /
• pp.53-60
• /
• 1997

In this paper, an efficient BILBO(named EBILBO) is proposed for batch testing application when a BIST (built-in self test) circuit is implemented on ASIC. In a large and complex circuit, the proposed algorithm of batch testing has one pin-count that can easily control 4 test modes in the normal speed of circuit operation. For the implementation of the BIST cifcuit, the test patern needed is generated by PRTPG(pseudo-random test pattern generator) and the ouput is observed by proposed algorithm is easily modified, such as the modelling of test pattern genration, signature EBILBO area and performance of the implemented BIST are evaluated using ISCAS89 benchmark circuits. As a resutl, in a circuit above 600 gates, it is confirmed that test patterns are genrated flexibly about 500K as EBILBO area is 59%, and the range of fault coverage is from 88.3% to 100%. And the optimized operation frequency of EBILBO designed and the area are 50MHz and 150K respectively. On the BIST circit of the proposed batch testing, the test mode of EBILBO is able to execute as realtime that has te number of s$\^$+/n$\^$+/(2s/2p-1) clocks simultaneously with the normal mode of circuit operation. Also the proposed algorithm is made of the library with VHDL coding thus, it will be widely applied to DFT (design for testability) that satisfies the design and test field.

• 한국환경복원기술학회지
• /
• 제9권1호
• /
• pp.100-111
• /
• 2006

This study was carried out to increase the efficiency of site investigation through the evaluation of the applicable methods of investigation for cutting slope design. In an effort to find out the applicability of the method employed during the slope investigation, some tests were carried out on 6 subjects i.e location of weak zones, characteristics of discontinuities, distribution of strata, in situ tests for geo-technical properties, laboratory test and estimation of weathering. The method was highly applicable and produced expected results during the test of weak zones, discontinuities and distribution of strata. In order to apply the method to in- situ test for geo-technical properties and laboratory test on soil and rock slope, a statistic analysis of the existing data were required in advance. However its design applicability on rock slope was good although actual cases of application were not many due to limitation of the cases for investigation. The method was frequently referenced but not actually applied for anti seismic design test and estimation of weathering.

• International Journal of Aeronautical and Space Sciences
• /
• 제14권1호
• /
• pp.99-104
• /
• 2013

Configuration design, analysis, and wind tunnel test of a vane-type multi-function air data probe (MFP) was described. First, numerical analysis was conducted for the initial configuration of the MFP in order to investigate aerodynamic characteristics. Then, the design was modified to improve static and dynamic stability for better response characteristics. The modified configuration design was verified through wind tunnel tests. The test results are also used to verify the accuracy of the analytical method. The analytically estimated aerodynamic damping provided by the Navier-Stokes equation solver correlated well with the wind tunnel test results. According to the calculation, the damping coefficient estimated from ramp motion analysis yielded a better correlation with the wind tunnel test than pitch oscillation analysis.

• ETRI Journal
• /
• 제27권2호
• /
• pp.140-152
• /
• 2005

In this paper, we present design features, implementation, and validation of a satellite simulator subsystem for the Korea Multi-Purpose Satellite-2 (KOMPSAT-2). The satellite simulator subsystem is implemented on a personal computer to minimize costs and trouble on embedding onboard flight software into the simulator. An object-oriented design methodology is employed to maximize software reusability. Also, instead of a high-cost commercial database, XML is used for the manipulation of spacecraft characteristics data, telecommand, telemetry, and simulation data. The KOMPSAT-2 satellite simulator subsystem is validated by various simulations for autonomous onboard launch and early orbit phase operations, anomaly operation, and science fine mode operation. It is also officially verified by successfully passing various tests such as the satellite simulator subsystem test, mission control element system integration test, interface test, site installation test, and acceptance test.