• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.3
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• pp.9-15
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• 2021

In this paper, the Embedded MEMS system to the power apparatus used Edge Impulse machine learning tools and therefore an improved predictive system design is implemented. The proposed MEMS embedded system is developed based on nRF52840 system and the sensor with 3-Axis Digital Magnetometer, I2C interface and magnetic measurable range ±120 uT, BM1422AGMV which incorporates magneto impedance elements to detect magnetic field and the ARM M4 32-bit processor controller circuit in a small package. The MEMS embedded platform is consisted with Edge Impulse Machine Learning and system driver implementation between hardware and software drivers using SensorQ which is special queue including user application temporary sensor data. In this paper by experimenting, TensorFlow machine learning training output is applied to the power apparatus for analyzing the status such as "Normal, Warning, Hazard" and predicting the performance at level of 99.6% accuracy and 0.01 loss.

• Journal of information and communication convergence engineering
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• v.19 no.3
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• pp.175-179
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• 2021

Enhancing the reliability of the system is important for recent system-on-chip (SoC) designs. This importance has led to studies on fault diagnosis and tolerance. Fault-injection (FI) techniques are widely used to measure the fault-tolerance capabilities of resilient systems. FI techniques suffer from limitations in relation to environmental conditions and system features. Moreover, a hardware-based FI can cause permanent damage to the target system, because the actual circuit cannot be restored. Accordingly, we propose a simulation-based FI framework based on the Verilog Procedural Interface for measuring the failure rates of SoCs caused by soft errors. We execute five benchmark programs using an ARM Cortex M0 processor and inject soft errors using the proposed framework. The experiment has a 95% confidence level with a ±2.53% error, and confirms the reliability and feasibility of using proposed framework for fault analysis in SoCs.

• Animal Systematics, Evolution and Diversity
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• v.35 no.2
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• pp.84-90
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• 2019

The brittle star, Amphistigma minuta H.L. Clark, 1938, was collected from Munseom Island, Jeju-do, Korea, by SCUBA diving. This species has distinct morphological features, as follows: a small disk with large papillae on the disk margin; slender arms and four arm spines at proximal; and oral parts the same as those of the genus Amphipholis. Additionally, we obtained partial sequences of the cytochrome c oxidase subunit I gene (COI) (513 bp) and compared them with sequences from Australian A. minuta and 13 other species of Amphiuridae. As a result, intraspecific pairwise distance was 0.4% between two Korean individuals and intraspecific distance between the Australian and the Korean populations was 2.6-2.8%, which indicates they should be considered as the same species. Ultimately, 15 species of the family Amphiuridae have currently been recorded in Korea, including A. minuta.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.169-172
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• 2010

유비쿼터스 화재 방재 시스템은 온도, 습도, 조도, 가속도, CO2, 등의 다양한 센서로부터 얻는 값을 이용해 화재를 판별하여 관리자에게 전달하고 시스템 설정 값에 따라 소화설비를 동작시키는 지능형 화재 탐지 시스템이다. 기존 화재 판별 기법은 크게 영상인식, 퍼지추론, 베이지안 추론으로 나뉠 수 있다. 본 논문에서는 앞선 기술들을 분석하고, ARM9 S3C2440/SHT-75를 이용한 센서기반 유비쿼터스 화재 방재 시스템 최적의 화재 판별 기술로서 가속도 알고리즘과 벡터 랜덤변수 표본공간 영역을 이용한 패턴인식 기술을 사용한 복합 화재 판별 방법을 제안한다.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.51.1-51.1
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• 2021

Spiral arms greatly affect gas flows and star formation in disk galaxies. We use local 3D simulations of vertically-stratified, self-gravitating, gaseous disks under a stellar spiral potential to study the effects of spiral arms on galactic star formation as well as formation of gaseous spurs/feathers. We adopt the TIGRESS framework to handle radiative heating and cooling, star formation, and ensuing supernova (SN) feedback. We find that more than 90% of star formation takes place inside spiral arms. The global star formation rate (SFR) in models with spiral arms is enhanced by less than a factor of 2 compared to the no-arm counterpart. This supports the picture that spiral arms do not trigger star formation but rather redistribute star-forming regions. Correlated SN feedback produces interarm feathers in both magnetized and unmagnetized models. These feathers live short, have parallel magnetic fields along their length, and are bounded by SN feedback in the lateral direction, in contrast to instability-induced feathers formed in our previous isothermal simulations.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2557-2562
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• 2024

A type of integrated multiple-single-channel analyzer (IMSCA) is described. The IMSCA works with an input pulse of 2-20 pC, and it can be directly connected to a scintillation detector, which eliminates the need for a linear amplifier. It consists of 64 input ports, so 1-64 detectors can be set by users according to different requirements. Two energy regions for each input channel can be simultaneously analyzed. Another advantage of the IMSCA is that it integrates with a high-speed pulse signal acquisition card and transmits data to the computer through the network. The maximum pulse through-rate is 1.4 MHz, and linearity can reach 0.1%. This IMSCA has been successfully used in enrichment detecting of nuclear fuel rod.

• Journal of Power System Engineering
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• v.5 no.3
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• pp.88-94
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• 2001

Stellite 12 alloy-powders were overlaid on 410 stainless steel valve seat using plasma transferred arc(PTA) process. Variation of the microstructure, hardness, wear and corrosion of overlaid deposit with current change was investigated. The deposit showed hypoeutectic microstructure, which was consisted of primary cobalt dendrite and networked $M_7C_3$ type eutectic carbides. As current increased, the amount of eutectic carbide decreased and its dendritic secondary arm spacing increased. Hardness of the deposit was decreased with increase of current. Stress relief heat treatment at $600^{\circ}C$ for two hours resulted in slight increase of hardness in the deposit and showed uniform hardness distribution in base metal without any hardened layer in HAZ. Specific wear decreased with increase of sliding distance. The deposit of high hardness with a lot of eutectic carbide showed relatively low specific wear. Initial corrosion current density of the deposit in 0.1N sulfuric acid was lower than those of 410 stainless steel, and showed a little variation with PTA current.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5446-5463
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• 2019

Parallel computing system components should be harmonized, and this harmonization is kept existent using synchronization time. Synchronization time affects the system in two ways. First, if we have too little synchronization time, some tasks face the problem of harmonization, as they need appropriate time to update and synchronize with the system. Second, if we allocate a large amount of time, stall system created. Random allocation of synchronization time for parallel systems slows down not only the booting time of the system but also the execution time of each application involved in the system. This paper presents a simulator used to test and allocate appropriate synchronization time for distributed and parallel heterogeneous systems. The simulator creates the parallel and heterogeneous system to be evaluated, and lets the user vary the synchronization time to optimize the booting time. NS3-cGEM5 simulator in this paper is formed by HLA-RTI federation integration of the two independent architecture and network simulators - NS3 and cGEM5. Therefore, nodes created on these simulators need synchronizations for harmonized system performance. We tested and allocated the appropriate synchronization time for our sample parallel system composed of one x86 server and three ARM clients.

• Journal of Korea Foundry Society
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• v.34 no.1
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• pp.6-13
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• 2014

The mechanical properties of low-pressure die cast (LPDC) A356-T6 automotive road wheels are evaluated and correlated with their corresponding microstructures. In this study, two types of alloy wheels processed using different LPDC gating system are investigated. The yield stress, tensile stress, and elongation values tested at room temperature are correlated with the secondary dendrite arm spacing (SDAS) with respect to the gating system, and are also compared with similar studies. The SDAS and precipitates are examined using optical microscopy, scanning electron microscopy (SEM) and energy-dispersive spectroscopy. The phase information is also investigated using X-ray diffraction. Charpy impact tests are also performed from $-100^{\circ}C$ to $200^{\circ}C$, and the fracture surfaces are examined using SEM. The impact energy is demonstrated to increase with increasing temperatures without exhibiting specific transition behaviors as in other nonferrous alloys. The fracture toughness is also evaluated using three point bend test with single-edged bend specimens. The obtained fracture toughness values are in good agreement with those in similar studies.

• Journal of Oriental Neuropsychiatry
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• v.23 no.1
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• pp.49-58
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• 2012

Objectives : The purpose of this research is to investigate the effects of acupuncture on the anxiety symptoms regarding Hwa-Byung. Methods : Acupuncture was applied on 15 participants, 4 males and 11 females. Hwa-Byung was diagnosed by Hwa-Byung Diagnostic Interview Schedule(HBDIS). Then clinical research STAI, BDI, VAS, HRV was carried out for investigation to analyze the change of each symptom between pre-acupuncture and post-acupuncture. Results : STAI, VAS were all significantly decreased. BDI decreased, but the decrease was not significant. All physical and psychological scores of HBDIS were significantly decreased excluding A2, B2, B3, B5, C1, C5. Subjects of HRV were different between pre-acupuncture and post-acupuncture, but the difference was not significant. Conclusions : The results suggest that acupuncture has positive effects on anxiety and other symptom of Hwa-Byung.