• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.35C no.12
• /
• pp.13-22
• /
• 1998

In this paper, we propose a high-performance BICS(built-in current sensor) which is fabricated in 0.8${\mu}{\textrm}{m}$ single-poly two-metal process for IDDQ testing of CMOS VLSI circuit. The CUT(circuit under test) is 4-bit full adder with a bridging fault. Using two nMOSs that have different size, two bridging faults that have different resistance values are injected in the CUT. And controlling a gate node, we experimented various fault effects. The proposed BICS detects the faulty current at the end of the clock period, therefore it can test a CUT that has a much longer critical propagation delay time and larger area than conventional BICSs. As expected in the HSPICE simulation, experimental results of fabricated chip demonstrated that the proposed BICS can exactly detect bridging faults in the circuit.

• The Journal of the Petrological Society of Korea
• /
• v.17 no.2
• /
• pp.83-94
• /
• 2008

The Pungcheon-myeon, Andong, consists mainly of Precambrian metamorphic rocks, Jurassic igneous rocks, Cretaceous sedimentary rocks (Hasandong, Jinju and Iljik Formations) and Cretaceous igneous rocks (gabbroic rocks, dykes), in which several major faults are developed; Andong fault of ENE trend, which is the boundary fault of the Cretaceous Gyeongsang Basin and the Precambrian-Jurassic basement (Yeongnam Massif), Namhu fault parallel to it, Maebong fault of NNW direction, bow-shaped Gwangdeok fault of ENE direction which is convex toward SSE direction, and Hahoe fault of NNE direction. This paper is researched the geological structures around these major faults by means of the detailed geometric analysis on beddings, joints, faults and drag folds. As a result, a reverse slip faulting of top-to-the SSE movement accompanied with a regional drag folding is recognized from the arrangement of bedding poles measured around the Gwangdeok and Hahoe faults at its northeastern extension, and a zone of Gwangdeok drag fold of 150-300 m width, which is wider at the central and eastern parts of Gwangdeok fault and narrower at its western part and Hahoe fault, is also defined. It indicates that the Hahoe and Gwangdeok faults are a single fault and their movements are coeval unlike the results of earlier reasearchers. And, In this area are recognized two types of faults [(E)NE${\sim}$EW(fault I), WNW${\sim}$NNW (fault II), trending faults] and four types of joints [EW (I), (N)NW (II), NNE (III), NE (IV) trending joints]. These fractures were formed at least through four different events, named as Dn to Dn+3 phases. (1) Dn phase; the formation of joint (I) (Gwangdeok joint) and the intrusion of acidic dykes of EW trend under the compression of EW direction. (2) Dn+1 phase; the formations of joint (II) (Maebong joint), lens-shaped boudinage of acidic dykes, oblique-slip reverse fault (Fault I-Gwangdeok fault) under the compression of (N)NW direction, and the formation of regional zone of Gwangdeok drag fold accompanying the Gwangdeok faulting. (3) Dn+2 phase; those of joint (III), Fault II (Maebong fault) by dextral strike-slip movement of Maebong joint under the compression of NNE direction, and the extension cutting of Dn+1 structures due to the Maebong faulting. (4) Dn+3 phase; the jointing (IV) and the reactivation of Fault II as oblique-slip type with predominant dextral motion which took place under the compression of NE direction. It also suggests that the Maebong fault is not a tear fault deveolped during thrust tectonics of the Andong and Gwangdeok faults but is a post-fault during different tectonic event.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.5
• /
• pp.557-565
• /
• 2014

We report the effect of basal-plane stacking faults (BSFs) on X-ray diffraction (XRD) of non-polar (11$\underline{2}$0) a-plane GaN films with different $SiN_x$ interlayers. Complete $SiN_x$ coverage and increased three-dimensional (3D) to two-dimensional (2D) transition stages substantially reduce BSF density. It was revealed that the Si-doping profile in the Si-doped GaN layer was unaffected by the introduction of a $SiN_x$ interlayer. The smallest in-plane anisotropy of the (11$\underline{2}$0) XRD ${\omega}$-scan widths was found in the sample with multiple $SiN_x$ layers, and this finding can be attributed to the relatively isotropic GaN mosaic resulting from the increase in the 3D-2D growth step. Williamson-Hall (WH) analysis of the (h0$\underline{h}$0) series of diffractions was employed to determine the c-axis lateral coherence length (LCL) and to estimate the mosaic tilt. The c-axis LCLs obtained from WH analyses of the present study's representative a-plane GaN samples were well correlated with the BSF-related results from both the off-axis XRD ${\omega}$-scan and transmission electron microscopy (TEM). Based on WH and TEM analyses, the trends in BSF densities were very similar, even though the BSF densities extracted from LCLs indicated that the values were reduced by a factor of about twenty.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.1
• /
• pp.22-28
• /
• 2013

Robotic GMA (Gas Metal Arc) welding process is one of widely acceptable metal joining process. The heat and mass inputs are coupled and transferred by the weld arc to the molten weld pool and by the molten metal that is being transferred to the weld pool. The amount and distribution of the input energy are basically controlled by the obvious and careful choices of welding process parameters in order to accomplish the optimal bead geometry and the desired quality of the weldment. To make effective use of automated and robotic GMA welding, it is imperative to predict online faults for bead geometry and welding quality with respect to welding parameters, applicable to all welding positions and covering a wide range of material thickness. MD (Mahalanobis Distance) technique was employed for investigating and modeling the GMA welding process and significance test techniques were applied for the interpretation of the experimental data. To successfully accomplish this objective, two sets of experiment were performed with different welding parameters; the welded samples from SM 490A steel flats. First, a set of weldments without any faults were generated in a number of repeated sessions in order to be used as references. The experimental results of current and voltage waveforms were used to predict the magnitude of bead geometry and welding quality, and to establish the relationships between weld process parameters and online welding faults. Statistical models developed from experimental results which can be used to quantify the welding quality with respect to process parameters in order to achieve the desired bead geometry based on weld quality criteria.

• Korean Chemical Engineering Research
• /
• v.58 no.3
• /
• pp.408-415
• /
• 2020

In this study, the AE-SOM method, which combines auto-encoder and self-organizing map, is used to detect and diagnose faults in EVA production process. Then, the fault propagation pathways are identified using Granger causality test. One year and seven months of operation data were obtained to detect faults of the process, and the process variables of the autoclave reactor are mainly analyzed. In the data pretreatment process, the data are standardized and 200 samples of each grade are randomly chosen to obtain a fault detection model. After that, the best matching unit (BMU) of each grade is confirmed by applying AE-SOM. The faults are determined based on each BMU. When a fault is found, the most causative variable of the fault is identified by using a contribution plot, and the fault propagation pathway is identified by Granger causality test. The prognostic of the two shutdowns is detected, and the fault propagation pathway caused by the faulty variable was analyzed.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.15 no.2
• /
• pp.45-50
• /
• 2005

During oxidation process, several type of defects are formed on the surface of the silicon crystal which was damaged mechanically before oxidation. As the size of abrasive particle increases multiple dislocation loops are produced favorably over oxidation-induced stacking faults, which are dominantly produced when ground with finer abrasive particle. These defects are not related with the crystal growth process like Czochralski or directional solidification. During directional solidification process, twins and stacking faults are the two major defects observed in the bulk of the silicon crystal. On the other hand, slip dislocations produced by the thermal stress are not observed. Thus, not only in single crystalline silicon crystal but also in multi-crystalline silicon, extrinsic gettering process with programmed production of surface defects might be highly applicable to silicon wafers for purification.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.6
• /
• pp.817-826
• /
• 2001

In this paper, the method of processing a blurred noisy signal has been researched. The conventional method of processing signal has faults which are slow-convergence speed and long time-consuming process at the singular point and in the ill condition. There is the process, the Gauss-Seidel's method to remove these faults, but it takes too much time because it processes signal repeatedly. For overcoming the faults, this paper shows a signal process method which takes shorter than the Tikhnov-Miller's by comparing the Tikhnov-Miller's with proposed algorithm and accelerating convergence speed at the singular point in the ill condition. In this paper, the conventional process method and proposed optimal algorithm were used to get a standard image (256 ＊ 256 ＊ 8bits),and then the results are simulated and compared each other in order to examine the variance of MSE ( Mean-Square Error ) by the acceleration parameter in the proposed two dimensional signal procedures. The result of the signal process and the processing time was measured at all change of acceleration parameter in order to verify the effectiveness of the proposed algorithm.

• Economic and Environmental Geology
• /
• v.20 no.3
• /
• pp.203-209
• /
• 1987

The gravity measurement has been conducted at 69 points with an interval of about 1km along the national road between Masan and Busan through Kimhae to study on the subsurface geology and structure of Kyongsang basin. The Bouguer gravity anomalies were obtained from the observed gravity values, and interpreted by means of the Fourier-series method and Talwani method for 2-dimensional body. The depth of Conrad discontinuity is about 14.8km at the west end of survey line, and increases smoothly to about 13.6km at the east end. But it is uplifted by about 500m between Yangsan and Dongnae faults. The depth of the basement of Kyongsang basin is about 4.8km at the west end. It decreases gradually passing Masan, and reaches the maximum depth of 5.6km at the 15km east of Masan. Hereafter, it starts to increase to 4.3km at the east end. It is also uplifted by about 500m between Yangsan and Dongnae faults. The Bulgugsa granites which cause two low Bouguer gravity anomaly zones are distributed in the vicinity of Masan at depth of about 3.5km and Kimhae area at depth of about 5.3km. Diorite, granodiorite, aplite, and felsite are distributed with various depth of about 1~1.7km, and Jusasan andesitic rocks, except porphyritic one located at the west of Kimhae, are distributed with depth of about 1km. Three fracture zones associated with faults are located at the places where v-shaped Bouguer gravity anomalies are appeared.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.3
• /
• pp.288-300
• /
• 2002

In this paper, a novel method of equalization of RF transceivers is suggested for MIMO(Multiple Input Multiple Output) antenna actively studied for high speed data transmission in the recent IMT-2000 system. The core of suggestion is in equalizing the transfer characteristics of multiple transceivers using feedback and memory during the predefined calibration time. This makes it possible to weight the signals in the intermediate frequency, which is easier in the application of recently developed DoA(Direction of Arrival) algorithms. In addition, the time varying optimum cell formation according to traffic is feasible by antenna beam-forming based on the DoA information. The suggested method of equalizing multiple transceivers are successfully verified using envelope simulation. two outputs. This paper is concerned with the diagnosis of multiple crosstalk-faults in OSM. As the network size becomes larger in these days, the convent.
nal diagnosis methods based on tests and simulation be.
me inefficient, or even more impractical. We propose a simple and easily implementable alg？ithm for detection and isolation of the multiple crosstalk-faults in OSM. Specifically, we develop an algorithm for isolation of the source fault in switc.
ng elements whenever the multiple crosstalk-faults are.
etected in OSM. The proposed algorithm is illustrated by an example of 16$\times$16 OSM.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.1
• /
• pp.96-101
• /
• 2014

Wind power is the fastest growing renewable energy source in the world and it is expected to remain so for some times. Recently, there is a constant need for the reduction of Operational and Maintenance(O&M) costs of Wind Energy Conversion Systems(WECS). The most efficient way of reducing O&M cost would be to utilize CMS(Condition Monitoring System) of WECS. CMS allows for early detection of the deterioration of the wind generator's health, facilitating a proactive action, minimizing downtime, and finally maximizing productivity. There are two types of faults such as mass unbalance and aerodynamic asymmetry which are related to wind turbine's rotor faults. Generally, these faults tend to generate various vibrations. Therefore, in this work a simple fault detection algorithm based on spectrums of vibration signals and simple max-min decision logic is proposed. Furthermore, in order to verify its feasibility, several simulation studies are carried out by using GH-bladed software.