• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2020년도 추계학술대회
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• pp.241-243
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• 2020

The high computational complexity of deep learning algorithms has led to the development of specialized hardware architectures. However, soft errors (bit flip) may occur in these hardware systems due to voltage variation and high energy particles. Many error correction methods have been proposed to counter this problem. In this work, we analyze an error correction mechanism based on repetition codes and an activation function. We test this method by injecting errors into weight filters and define an ideal error rate range in which the proposed method complements the accuracy of the model in the presence of error.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.33-36
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• 2001

An automatic TCXO frequency-temperature test apparatus was firstly developed by using thermoelectric device may. The developed system swing stably the test temperature range from -40$^{\circ}C$ to +80$^{\circ}C$ for about 1 hour The rising temperature ratio was fairly linear with time in this test temperature range. The temperature could be controlled error in error range of ${\pm}$0.05$^{\circ}C$ in this system. The frequency-Temperature properties of TCXO or the thermoelectric properties of other electric device.

• Journal of the Korean Statistical Society
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• 제8권1호
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• pp.23-36
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• 1979

In the multiple linear regression model a class of weighted least absolute error estimaters, which minimize the sum of weighted absolute residuals, is proposed. It is shown that the weighted least absolute error estimators with Wilcoxon scores are equivalent to the Koul's Wilcoxon type estimator. Therefore, the asymptotic efficiency of the proposed estimator with Wilcoxon scores relative to the least squares estimator is the same as the Pitman efficiency of the Wilcoxon test relative to the Student's t-test. To find the estimates the iterative weighted least squares method suggested by Schlossmacher is applicable.

• 한국시뮬레이션학회논문지
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• 제26권3호
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• pp.55-63
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• 2017

곡사포의 사격오차는 탄착의 분산도와 탄착중심오차(MPI)를 포괄하는 용어로, 본 연구에서는 사격시험을 수행하지 않고 정량적 분석을 통해 사격오차를 예측하는 기법에 대해 논하고자 한다. 기존에도 곡사포의 사격오차를 예측하기 위한 분석기법은 있었지만, 오차에 관여하는 영향요소들에 대한 정보가 부족하여 활용이 제한되었다. 본 연구에서는 이런 문제를 해결하기 위해 누적된 시험이 수행된 기존 무기체계 시험결과를 활용하여, 오차의 원인이 되는 각 요소 값들을 역으로 산출하는 방식을 제안한다. 이 과정에서 항공공학 분야에서 흔히 사용되는 최적화 알고리즘을 이용한 입력계수 추출 방식을 도입하였다. 최적화 알고리즘으로는 CMA-ES라는 진화적 기법을 소개하며, 적용 결과에 대하여 해설하였다. 이런 과정을 통해 얻은 사격오차요인 값은 향후 신규 무기체계 개발에 있어 성능요구사항 산출에 사용될 수 있으며, 야전에서의 곡사포 정확도 향상에도 기여할 것으로 보인다.

• 한국기계가공학회지
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• 제20권12호
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• pp.136-144
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• 2021

The purpose of this study was to develop and verify a precision transmission error measurement system for a gear pair. The transmission error measurement system of the gear pair was developed as a measurement unit, signal processing unit, and signal analysis unit. The angular displacement for calculating the transmission error of the gear pair was measured using an encoder. The signal amplification, interpolation, and transmission error calculation of the measured angular displacement were conducted using a field-programmable gate array (FPGA) and a real-time processor. A high-pass filter (HPF) was applied to the calculated transmission error from the real-time processor. The transmission error measurement test was conducted using a gearbox, including the master gear pair. The same test was repeated three times in the clockwise and counterclockwise directions, respectively, according to the load conditions (0 - 200 N·m). The results of the gear transmission error tests showed similar tendencies, thereby confirming the stability of the system. The measured transmission error was verified by comparing it with the transmission error analyzed using commercial software. The verification showed a slight difference in the transmission error between the methods. In a future study, the measurement and analysis method of the developed precision transmission error measurement system in this study may possibly be used for gear design.

• 한국광학회지
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• 제28권6호
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• pp.290-294
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• 2017

카세그레인 망원경은 오목한 주경과 볼록한 부경으로 이루어져있다. 특히 부경의 경우 크기는 작지만 볼록한 형태로 빛을 모두 퍼트려 파면오차 측정이 어렵다. 본 논문에서는 비구면 계수가 여러 개인 볼록비구면 반사경의 파면오차를 Simpson-Oland-Meckel (SOM) 힌들 테스트를 적용하여 측정하였다. 그리고 실험 구성에서 발생하는 계통오차를 분리해내기 위해 QN 절대측정법을 추가로 적용함으로써 힌들 렌즈 제작 및 정렬 오차를 포함한 계통오차를 보정하고 볼록비구면 반사경만의 파면오차를 구하였다. 이렇게 구한 볼록비구면 반사경의 파면오차와 QED사의 ASI (Aspheric Stitching Interferometer)로 측정한 파면오차와 비교한 결과, 모두 $45^{\circ}$ 방향의 비점수차 형태를 가지며 rms 값의 차이가 약 2.5 nm rms 이내로 매우 작음을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권8호
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• pp.347-353
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• 2002

This paper presents an accurate method for measuring the ground resistance in powered grounding system. Most of substations and electric power equipments are interconnected to an extensive grounding network of overhead ground wires, neutral conductors of transmission lines, cable shields, and etc. The parasitic effects due to circulating ground currents and ground potential rise make a significant error in measuring the ground resistance. The test current transition method was proposed to reduce the effects of stray ground currents, ground potential rise and harmonic components in measurements of the ground resistance for powered grounding systems. The instrumental error of the test current transition method is decreased as the ratio of the test current signal to noise(S/N) increases. It was found from the test results that the proposed measuring method of the ground resistance is more accurate than the conventional fall-of-potential method or low-pass filter method, and the measuring error was less than 3[%]when S/N is 10.

• The Journal of Korean Physical Therapy
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• 제30권2호
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• pp.54-57
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• 2018

Purpose: Most studies have reported pain in the head-neck and upper-limbs according to smartphone usage, which is related to the proprioception sense in the head and neck, but there have been few studies. Therefore, the aim of this study was identify the adverse effects of the proprioceptive sense in the head-neck according to smartphone usage. Methods: Twenty-seven young adults (male: 9, female: 18) were enrolled in this study. The proprioceptive sense was measured through the joint reposition sense error and neural positon error in the head-neck during smartphone usage for 0, 5, and 20 minutes. The Noraxon MyoMotion system was used to record the joint position angle and neutral positon in the head-neck. One-way repeated ANOVA was used to identify the differences between the three smartphone use durations and the least-squares difference was used as a post hoc test. The data were analyzed using SPSS 18.0 software. Results: The joint reposition sense error and neural positon error in the head-neck were significantly different among the 0, 5, and 20 minutes of smartphone usage (p<0.05). In the post hoc test, the joint reposition sense error and neural positon error showed a significant difference between smartphone use for 0 minute and 5 minute, and between smartphone use for 0 minute and 20 minutes. Conclusion: This study suggests that smartphone use within 5 minutes can have adverse effects on the proprioceptive sense. Therefore, it is necessary to consider the appropriate use time and break time when using smart phones.

• 동의신경정신과학회지
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• 제9권2호
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• pp.45-51
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• 1998

Purpose : This study has an experiment on finding how Hyangbujapamultang advanced the learning and memory of rat to find the method to improve the failure of memory which is the symptom of dementia.Method : In the experiment, rats were divided the control group (14 rat) which medicate the excipient into the sample group (17 rat) which medicates Hyangbujapalmutang. And the learning ability test and the memorv test was practiced to using the task of radial arm maze.The learning ability test had the presupposition that, when a rat which frequents 8 tracks makes am error not exceeding one time for 3 days without a break, it passes the test.First experiment compared total days when the control group passed the test with total days when the sample group it.The memory test practiced after 24 hours when the learning ability test was over. When a rat frequents 4 tracks, the gates is cut off during 30 seconds. Here the number of error at the control group with that of the sample group.Result: In the learning ability test, the sample group needed 5.82${\pm}$0.37 days to pass the test and the control group needed 6.43${\pm}$0.67 days. In the memory test, the sample group errored 0.29${\pm}$0.37 times and the control group errored 1.86${\pm}$0.78 times.Conclusion : In the learning ability test, the sample group passed the test earlier than the control group, but any statistical correlationship couldn't be found in it. In the memory test, the sample group had the pregnant reduction of the number of error in comparison with the control group.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.553-556
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• 2008

전기전도도에 의한 콘크리트의 염소이온 침투저항성 시험방법에 의해 동일 배치의 10개의 콘크리트 공시체의 염소이온 투과시험을 실시하였다. 실험결과 동일한 배합의 시료에 대한 염소이온 투과시험 결과 변동계수가 24% 정도로 나타나고 있어, 이 방법에 의해 얻어진 데이터의 신뢰성은 그다지 높지 않다는 결론을 도출할 수 있었다. 이러한 오차는 구성 재료 자체의 불균질성, 배합상의 오차, 시험방법 상의 오차 등이 모두 복합적으로 작용하여 일어나는 것으로 얻어진 결과를 활용하고자 할 때 이러한 영향으로 인해 도입되는 오차의 범위를 고려하여야 할 것이다. 특히 1개의 공시체에 대한 1회의 시험값을 토대로 연구결과를 내려는 경우 큰 오류를 범할 수 있음을 주지해야 한다.