• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.601-602
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• 2011

In wireless sensor networks, coverage problem is a fundamental issue that has attracted considerable attention in recent years. Most node scheduling patterns utilize the adjustable range of sensor to minimize the sensing energy consumption. However, a large source of consumption of communication energy of sensor is not strictly taken into account. In this paper, we introduce an energy-efficient pattern that is used to minimize the communication energy consumption of a sensor network. Calculations and extensive simulation are conducted to evaluate the efficiency of the new pattern comparing to existing ones.

• 소성∙가공
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• 제33권2호
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• pp.123-131
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• 2024

Plastic, the main material of FFF-type 3D printing, exhibits lower strength compared to metal. research aimed at increasing strength is needed for use in various industrial fields. This study analyzed three X-shape infill patterns(grid, lines, zigzag) with similar internal lattice structure. Moreover, tensile test considering weight and printing time was conducted based on the infill line multiplier and infill overlap percentage. The three X-shape infill patterns(grid, lines, zigzag) showed differences in nozzle paths, material usage and printing time. When infill line multiplier increased, there was a proportional increase in tensile strength/weight and tensile strength/printing time. In terms of infill overlap percentage, the grid pattern at 50% and the zigzag and lines patterns at 75% demonstrated the most efficient performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권10호
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• pp.2679-2691
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• 2012

In this paper, a high accuracy stereo reconstruction method for surgery instruments positioning is proposed. Usually, the problem of surgical instruments reconstruction is considered as a basic task in computer vision to estimate the 3-D position of each marker on a surgery instrument from three pairs of image points. However, the existing methods considered the 3-D reconstruction of the points separately thus ignore the structure information. Meanwhile, the errors from light variation, imaging noise and quantization still affect the reconstruction accuracy. This paper proposes a method which takes the structure information of surgical instruments as constraints, and reconstructs the whole markers on one surgical instrument together. Firstly, we calibrate the instruments before navigation to get the structure parameters. The structure parameters consist of markers' number, distances between each markers and a linearity sign of each instrument. Then, the structure constraints are added to stereo reconstruction. Finally, weighted filter is used to reduce the jitter. Experiments conducted on surgery navigation system showed that our method not only improve accuracy effectively but also reduce the jitter of surgical instrument greatly.

• 소성∙가공
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• 제19권3호
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• pp.167-172
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• 2010

Roll-to-roll forming process is one of important metal processing technology because the process is simple and economical. These days, with these merits, roll-to-roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. The forming of micro pattern for small electric device such as LCD panel by incremental roll forming process is analyzed. Firstly, the optimum analysis conditions are found by several analyses. And then, formability is analyzed for various protrusion shapes at various forming temperatures. The formability is evaluated in terms of filling ratio and damage value. The filling ratio is defined from the tool geometry and critical damage is determined from the analysis of uniaxial tensile test. Finally, optimum forming conditions that guarantee the successful forming are found.

• 제어로봇시스템학회논문지
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• 제15권8호
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• pp.778-785
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• 2009

This paper presents a Gabor texture feature extraction method for classification of discolored Metal pad images using GPU(Graphics Processing Unit). The proposed algorithm extracts the texture information using Gabor filters and constructs a pattern map using the extracted information. Finally, the golden pad images are classified by utilizing the feature vectors which are extracted from the constructed pattern map. In order to evaluate the performance of the Gabor texture feature extraction algorithm based on GPU, a sequential processing and parallel processing using OpenMP in CPU of this algorithm were adopted. Also, the proposed algorithm was implemented by using Global memory and Shared memory in GPU. The experimental results were demonstrated that the method using Shared memory in GPU provides the best performance. For evaluating the effectiveness of extracted Gabor texture features, an experimental validation has been conducted on a database of 20 Metal pad images and the experiment has shown no mis-classification.

• 소성∙가공
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• 제19권8호
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• pp.474-479
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• 2010

Newly suggested hybrid LED package can reduce the number of LED processes and enhance light efficacy in virtue of its integrated optical patterns. Square-type pyramid pattern was chosen for the integrated optical pattern in this study, and it was proved that the pattern enhances illuminance about three times and luminance about two and half times by optical simulation. Square-type pyramid patterns of 0.02mm height and 0.04mm pitch were successively machined on a copper mold which is necessary for imprinting the integrated pattern. Hybrid LED package with integrated optical pattern will be manufactured with ultra-fine machined mold in future study.

• 소성∙가공
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• 제23권8호
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• pp.507-512
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• 2014

The objective of the current investigation is to establish techniques in micro pattern forming operations of polymeric circular tubes by using hydrostatic pressing. This method was developed and successfully applied to the micro pattern forming on polymeric plates. The key idea of the new technique is to pressurize multiple vacuum-packed substrate-mold stacks above the glass transition temperature of the polymeric substrates. The new process is thought to be a promising micro-pattern fabrication technique for two reasons; first, (hydro-) isostatic pressing ensures a uniform micro-pattern replicating condition regardless of the substrate area and thickness. Second, multiple curved substrates can be patterned at the same time. With the prototype forming machine for the new process, micro prismatic array patterns, 25um in height and 90 degrees in apex angle, were successfully made on the PMMA circular tubes with diameters of 5~40mm. These results show that this process can be also used in the micro pattern forming process on curved plates such as circular tube.

• 대한의용생체공학회:의공학회지
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• 제4권1호
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• pp.37-44
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• 1983

This paper deals with the processing of statistical pattern classification of unifunctional EMG signal. The signal was detected from bicep and tricep of a simulated amputees instead of below the humerus amputees or paralyzed persons.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.868-872
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• 2005

Individual management of the animal is the first step towards reaching the goal of precision livestock farming that aids animal welfare. Accurate recognition of each individual animal is important for precise management. Electronic identification of cattle, usually referred to as RFID (Radio Frequency Identification), has many advantages for farm management. In practice, however, RFID implementations can cause several problems. Reading speed and distance must be optimized for specific applications. Image processing is more effective than RFID for the development of precision farming system in livestock. Therefore, the aim of this paper is to attempt the identification of cattle by using image processing. The majority of the research on the identification of cattle by using image processing has been for the black-and-white patterns of the Holstein. But, native Japanese and Korean cattle do not have a consistent pattern on the body, so that identification by pattern is impossible. This research aims to identify to Japanese black cattle, which does not have a black-white pattern on the body, by using image processing and a neural network algorithm. 12 Japanese black cattle were tested. Values of input parameter were calculated by using the face image values of 12 cows. The face was identified by the associate neural memory algorithm, and the algorithm was verified by the transformed face image, for example, of brightness, distortion, noise and angle. As a result, there was difference due to a transformation ratio of the brightness, distortion, noise, and angle. The algorithm could identify 100% in the range from -30 to +30 degrees of brightness, -20 to +40 degrees of distortion, 0 to 60% of noise and -20 to +30 degree of angle transformed images.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.40-43
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• 1997

This paper presents a 3D object recognition method for generation of 3D environmental map or obstacle recognition of mobile robots. An active light source projects a stripe pattern of light onto the object surface, while the camera observes the projected pattern from its offset point. The system consists of a laser unit and a camera on a pan/tilt device. The line segment in 2D camera image implies an object surface plane. The scaling, filtering, edge extraction, object extraction and line thinning are used for the enhancement of the light stripe image. We can get faithful depth informations of the object surface from the line segment interpretation. The performance of the proposed method has demonstrated in detail through the experiments for varies type objects. Experimental results show that the method has a good position accuracy, effectively eliminates optical noises in the image, greatly reduces memory requirement, and also greatly cut down the image processing time for the 3D object recognition compared to the conventional object recognition.