• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.659-661
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• 2011

In this paper, we propose a study of scheme to detect mobile object. In special zone needed detection, sensor network based system development can provide safety of pedestrian. Instead current CCTV, intelligent sensor network and service can provide reliability to guarantee safe zone. Base on pedestrian characteristic, if unusual situation is detected and it is included in previous agreed scenario, safety service can be provided.

• Analytical Science and Technology
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• v.35 no.5
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• pp.218-227
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• 2022

A simple and fast throughput flow injection (FI) system with a merging-zone technique was designed to determine ferrous and ferric in an aqueous solution. The method is based on the direct reaction of ferrous with a Bathophenanthroline reagent (Bphen) in acidic media. The forming red complex absorbs light at 533 nm. All conditions of the flow injection system were investigated. The analytical curve of ferrous was linear in the range of 0.07 to 4 mg/L with an r² value of 0.9968. The detection and quantification limits were 0.02 and 0.04 mg/L, respectively. The molar absorptivity and Sandell's sensitivity were 4.0577 × 10⁶ L/mol cm and 25 × 10^-5 ㎍/cm², respectively. The homemade valve was low-cost with high repeatability (n = 7) at an RSD of 1.26 % and zero dead volume. The values of the dispersion coefficient were 2.318, 2.022, and 1.636 for the concentrations of 0.2, 1, and 3 mg/L, respectively. The analysis throughput of the designed flow injection unit was 57 sample per hour.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.11
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• pp.1445-1454
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• 1995

In this study, we have developed a prototype of the automatic defects detection system for capsule inspection using the computer vision techniques. The subjects for inspection are empty hard capsules of various sizes which are made of gelatine. To inspect both sides of a capsule, 2-stage recognition is performed. Features we have used are various lengths of a capsule, area, linearity, symmetricity, head curvature and so on. Decision making is performed based on average value which is computed from 20 good capsules in training and permission bounds in factories. Most of time-consuming process for feature extraction is computed by hardware to meet the inspection speed of more than 20 capsules/sec. The main logic for control and arithmetic computation is implemented using EPLD for the sake of easy change of design and reduction in time for developement. As a result of experiment, defects on size or contour of binary images are detected over 95%. Because of dead zone in imaging system, detection ratio of defects on surface, such as bad joint, chip, speck, etc, is lower than the former case. In this case, detection ratio is 50-85%. Defects such as collet pinch and mashed cap/body seldom appear in binary image, and detection ratio is very low. So we have to process the gray-level image directly in partial region.

• Journal of Power Electronics
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• v.19 no.2
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• pp.509-518
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• 2019

A novel islanding detection method is proposed in this paper. It is based on a frequency drooping PLL, which was presented in a previous work. The cause of errors in the non-detection zone (NDZ) of conventional frequency disturbance islanding detection methods (IDM) is analyzed. A frequency drooping phase-locked-loop (FD-PLL) is introduced into a single-phase grid-connected inverter (SPGCI), which can guarantee that grid current is in phase with the grid voltage. A novel FD-PLL IDM is proposed by improving this PLL. In order to verify the performance of the proposed FD-PLL IDM, a full performance comparison between the proposed IDM and typical existing active frequency drift IDMs is carried out, which includes both dynamic performance and steady performance. With the same NDZ, the total harmonic distortion of the grid-current in the dynamic process and steady state is analyzed. The proposed FD-PLL IDM, regardless of the dynamic or steady process, has the best power quality. Experimental and simulation results verify that the proposed FD-PLL IDM has excellent performance.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.286-292
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• 2020

This study presents an angular-based measurement on three-dimensional paper-based analytical devices (3D-PADs) for quantitative detection of albumin without using an image analyzer. We demonstrate a simple quantitative and straightforward approach based on the angle of the discolored area as detection criteria. 3D-PADs are rapidly fabricated by the wax-printing and laminating process. The 3D-PADs are treated with citrate buffer and tetrabromophenol blue to react with albumin in a sample solution. Dropping sample solution into sample pad in the 3D-PAD, fluid flows toward the assay zone laterally and vertically by capillary action. We find that the change of angle of the discolored area correctly reflects the concentration of albumin and is reliable determinant for the measurement of the albumin concentration. It is the first demonstration of angular-based detection as a simple, inexpensive, and equipment-free approach for point-of-care diagnosis.

• Journal of Korean Society of Transportation
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• v.34 no.4
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• pp.354-372
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• 2016

This study identified factors affecting the crash severity at freeway work zones. A nice feature of this study was to take into account the characteristics of work zone traffic management in analyzing traffic safety concerns. In addition to crash records, vehicle detection systems (VDS) data and work zone historical data were used for establishing a dataset to be used for statistical analyses based on an ordered probit model. A total of six safety improvement strategies for freeway work zones, including traffic merging method, guidance information provision, speed management, warning information systems, traffic safety facility, and monitoring of effectiveness for countermeasures, were also proposed.

• International Journal of Aeronautical and Space Sciences
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• v.10 no.1
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• pp.37-45
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• 2009

A method of conflict detection and resolution is described by using simple geometric approach. Two VAVs are dealt with and considered as point masses with constant velocity. This paper discusses en route aircraft which are assumed to be linked by real time data bases like ADS-B. With this data base, all DAVs share the information each other. Calculating PCA (Point of Closest Approach), we can evaluate the worst conflict condition between two VAVs. This paper proposes one resolution maneuvering logic, which can be called 'Vector Sharing Resolution'. In case of conflict, using miss distance vector in PCA, we can decide the directions for two VAVs to share the conflict region. With these directions, VAVs are going to maneuver cooperatively. First of all, this paper describes some '2-D' conflict scenarios and then extends to '3-D' conflict scenarios.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.9-10
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• 2012

AFD(Active Frequency Drift), SMS(Slip-Mode frequency Shift)를 비롯한 주파수 이동 단독 운전 검출 방법은 단독 운전 발생 후, 계통의 주파수를 정상 운전 범위 밖으로 이동시켜 OUF(Over/Under Frequency) 릴레이를 동작하게 만들어 단독 운전을 검출한다. 이 방법들의 불검출 영역은 알고리즘에 의한 전류 위상각 변화율과 부하 역률 각 변화율 사이의 관계, 그리고 단독 운전 후 정상 상태(steady state) 운전 주파수에 의해 결정된다. 본 논문에서는 불검출 영역에 영향을 미치는 부하 역률 각 변화율을 분석하고 그를 바탕으로, 설계한 Q(Quality)-factor보다 낮은 Q-factor를 갖는 부하 조건에서는 항상 단독 운전을 검출할 수 있는 설계 방법을 제시한다. 제안된 방법의 유효성은 모의실험 및 실험으로 검증되었다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.2
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• pp.87-92
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• 2006

This paper supplements shortcoming of radioactivity check by detecting defect of SWP weld zone using ultrasonic wave. Manufacture 2 stage robot detection systems that can follow weld bead of SWP by method to detect weld defects of SWP that shape of weld bead is complex for this as quantitative. Also, through signal processing ultrasonic wave defect signal system of GUI environment that can grasp easily existence availability of defect because do videotex compose. Ultrasonic wave signal of weld defects develops artificial intelligence style sightseeing system to enhance pattern recognition of weld defects and the classification rate using neural net. Classification of weld defects that do fan Planar defect and that do volume defect of by classify.

• Biomedical Science Letters
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• v.17 no.2
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• pp.135-140
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• 2011

We compared three EDTA-based phenotypic screening methods for detecting IMP-1 and VIM-2 type metallo-${\beta}$- lactamase (MBL)-producing isolates of Acinetobacter and Pseudomonas spp., EDTA-double disk synergy test (EDTADDST), Etest MBL, and imipenem (IPM)-EDTA disk test. A total of 183 isolates (65 Acinetobacter spp. and 118 Pseudomonas spp. showing IPM resistance), confirmed to MBL genes by PCR, were used. The criteria for MBL production were (i) presence of a synergistic zone between IPM and EDTA disks in EDTA-DDST, (ii) reduction of IPM minimal inhibitory concentration by ${\geq}$ 3 twofold dilutions in the presence of EDTA in the Etest MBL, and (iii) ${\geq}$ 7 mm increase in the inhibition zone around the IPM plus EDTA disks compared with a sole IPM disk in the IPM-EDTA disk test. In this study using 87 MBL-producing and 96 MBL-nonproducing isolates, the sensitivities/specificities of EDTA-DDST, Etest MBL and IPM-EDTA disk tests were 94.3/78.1%, 89.7/91.7%, and 97.7/95.8%, respectively. When the threshold for the increase of the inhibition zone around the IPM plus EDTA disk over a sole IPM disk was altered to ${\geq}$ 5 mm and ${\geq}$ 8 mm for Acinetobacter spp. and Pseudomonas spp., respectively, the sensitivity and specificity of the test were 98.9% and 96.9%, respectively. Of the three EDTA-based phenotypic tests, the IMP-EDTA disk test was superior for detection of MBL-producing isolates.