• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.22-30
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• 2023

The portable mobile devices with high performance and high speed 5G network activate and explode the demands for ubiquitous information services that remove the limitations of time for the communication and places to request for the information. NN (Nearest Neighbor) search is one of the most important types of queries to be processed efficiently in the information services. Various indexes have been proposed to support efficient NN search in the wireless broadcast system. The indexes adopting Hilbert curve, grid partition or Voronoi diagram enable the clients to search for NN quickly in the wireless broadcast channel. It is necessary that an efficient means to evaluate the performances of various indexes. In this paper, we propose an open framework that can adopt a variety of indexing schemes and evaluate and compare the performances of them. The proposed framework is organized with open and flexible structure that can adopt hybrid indexing schemes extensible to Voronoi diagram as well as simple indexing schemes. With the implemented framework, we demonstrate the efficiency and scalability and flexibility of the proposed framework by evaluating various indexing schemes for NN query.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.220-230
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• 1993

Photoelastic isochromatic fringes related to the difference of principal stresses have some bandwidth whose light intensities are not constant and asymmetrical in experimental images. Hence, it is difficult to measure fringe order accurately at a data point by visual observation. In this study, a method of fringe sharpening, which can extract shapened lines from both full-and half-order fringes by digital image processing, is developed. To test the method, various simple photelastic fringe patterns are simulated and their images are processed to yield sharpened lines. The method is then applied to general problems such as images of a circular disk compressed by diametrically concentrated loads and a circular cylinder sybject to internal pressure. The procedure is proved to be capable of extracting sharpened lines accurately from photoelastic isochromatic fringes.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1222-1228
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• 2002

This research is the development of a flexible tactile sensor array for service robots using PVDF (polyvinylidene fluoride) film for the detection of a contact state in real time. The prototype of the tactile sensor which has 8${\times}$8 array using PVDF film was fabricated. In the fabrication procedure, the electrode patterns and the common electrode of the thin conductive tape were attached to both sides of the 281$\mu\textrm{m}$ thickness PVDF film using conductive adhesive. The sensor was covered with polyester film for insulation and attached to the rubber base for a stable structure. The proposed fabrication method is simple and easy to make the sensor. The sensor has the advantages in the implementing for practical applications because its structure is flexible and the shape of the each tactile element can be designed arbitrarily. The signals of a contact force to the tactile sensor were sensed and processed in the DSP system in which the signals are digitized and filtered. Finally, the signals were integrated for taking the force profile. The processed signals of the output of the sensor were visualized in a personal computer, and the shape and force distribution of the contact object were obtained. The reasonable performance for the detection of the contact state was verified through the sensing examples.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.11
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• pp.34-43
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• 1999

A high-speed image processor (HIP) is implemented for a high-speed multi-function peripheral. HIP has a binarization architecture with unified data path. It has the pixel-by-pixel pipelined processing to minimize size of the external memory. It performs pre-processing such as shading correction, automatic gain control (AGC), and gamma correction, and also drives external CCD or CIS modules. The pre-processed data can be enlarged or reduced. Various binarizatin algorithms can be processed in the unified archiecture. The embedded binarization algorithms are simple thresholding, high pass filtering, dithering, error diffusion, and thershold modulated error diffusion. These binarization algorithms are unified based on th threshold modulated error diffusion. The data path is designed to share the common functional block of the binarization algorithms. The complexity of the controls and the gate counts is greatly reduced with this novel architecture.

• Journal of Korea Multimedia Society
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• v.8 no.2
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• pp.201-210
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• 2005

This paper proposes a power efficient 2-dimensional DCT/IDCT architecture driven by input data to be processed. The architecture achieves low power by taking advantage of the typically large fraction of zero and small-valued input processing data in video and image data compression. In particular, it skips multiplication by zero and dynamically activates/deactivates required bit-slices of fine-grain bit partitioned adders within multipliers and accumulators using simple input ANDing and bit-slice MASKing. The processed results from 1-D DCT/IDCT do not have unnecessary sign extension bits (SEBs), which are used for further power reduction in matrix transposer. The results extracted by bit-level transition activity simulations indicate significant power reduction compared to conventional designs.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.373-373
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• 2014

Resistive-change random access memory (ReRAM) device is one of the promising candidates owing to its simple structure, high scalability potential and low power operation. Many resistive switching devices using transition metal oxides materials such as NiO, Al2O3, ZnO, HfO2, $TiO_2$, have attracting increased attention in recent years as the next-generation nonvolatile memory. Among various transition metal oxides materials, HfO2 has been adopted as the gate dielectric in advanced Si devices. For this reason, it is advantageous to develop an HfO2-based ReRAM devices to leverage its compatibility with Si. However, the annealing temperature of these high-k thin films for a suitable resistive memory switching is high, so there are several reports for low temperature process including microwave irradiation. In this paper, we demonstrate the bipolar resistive switching characteristics in the microwave irradiation annealing processed Ag/HfO2/Pt ReRAM device. Compared to the as-deposited Ag/HfO2/Pt device, highly improved uniformity of resistance values and operating voltage were obtained from the micro wave annealing processed HfO2 ReRAM device. In addition, a stable DC endurance (>100 cycles) and a high data retention (>104 sec) were achieved.

• Journal of Pharmaceutical Investigation
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• v.38 no.1
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• pp.23-29
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• 2008

Red ginseng is made of white ginseng through the steaming and drying procedure. In this process, the amounts of toxic elements of ginseng are decreased and those of effective components, ginsenosides are increased. In order to identify the components alteration of white ginseng by processing time, we applied HPLC-based metabolomics approach combined with the principal component analysis (PCA) multivariate analysis. White ginsengs were steamed at 0, 1, 2, 4, 8 and 16 h, respectively and followed by drying process at moderate temperature. Then the steamed ginsengs and the commercial red ginsengs were analyzed by HPLC. On the basis of HPLC results, PCA multivariate analysis was applied for evaluating the quality of red ginseng, which showed the processed ginsengs are grouped by processed time because less polar ginsenosides were increased in proportion as the steaming time was increased. The purchased red ginsengs were distributed in the range of $0{\sim}1$ hour steaming time. This pilot experiment suggests that HPLC-based metabolomics approach is able to allow the quality of herbal medicines to be controlled with a simple and economic method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.411-418
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• 2004

This paper is the study about a method for determining the azimuth of a baseline by measuring the apparent direction of the Sun. It is simple to realize this method, as it requires, in addition to the apparent direction of the Sun already measured, the observation time and the latitude and the longitude of the survey point. Comparing the azimuths determined by this method and those determined by the PDGPS(Post Processed Differential GPS) on 3 different baselines, the differences(PDGPS - this method) between the azimuths determined by two methods were -13", +45" and +24" respectively. It can be an effective and rapid tool in cases that require the accuracy lower than 1 arc-min.than 1 arc-min.

• Communications for Statistical Applications and Methods
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• v.15 no.1
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• pp.105-115
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• 2008

Judgement post-stratification is a new sampling method developed by MacEachern et al. (2004). This article suggests that the judgement post-stratification method can be a good alternative for the simple random sampling when analyzing real-world environmental data. It becomes an important task to accurately measure the output of a recycling facility since the EPR (Extended Producer Responsibility) system takes effect on 2003. However, the total weight of materials processed in the recycling facility may not be a proper measure because the materials are frequently mingled with other non-recycling materials. Therefore, it is necessary to estimate the mixture ratio of non-recycling materials among the total materials admitted in the facility. Unfortunately, the size of sample in a recycling facility is restricted due to the inconvenience of sampling procedure such as safety, odor, time and classification of non-recycling materials. In this article, we showed the relative efficiency of the judgement post-stratification method over the simple random sampling method for equal sample sizes using Monte Carlo simulation. Furthermore, we applied the judgement post-stratification method on the 2004 recycling data and showed that it can replace the simple random sampling even with smaller observations.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1271-1276
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• 2004

For Exp. 1, one hundred twenty Duroc${\times}$ Yorkshire${\times}$Landrace pigs (6.34${\pm}$ 0.70 kg average initial BW) were used in a 35 d growth assay. There were six pigs per pen and four pens per treatment. Dietary treatments included 1) NC (negative control; basal diet), 2) PC (positive control; added 5% HP $300^{(R)}$, HAMLET PROTEIN A/S, as protein source), 3) PSP 2.5 (added 2.5% $Pepsoygen^{(R)}$, Genebiotech Co. Ltd., as protein source), 4) PSP 5.0 (added 5% $Pepsoygen^{(R)}$ as protein source), and 5) PSP 7.5 (added 7.5% $Pepsoygen^{(R)}$ as protein source). For d 21, ADFI was increased in pigs fed PSP diets compared with PC diet (p<0.05). ADG was tended to improve as concentration of PSP in the diets was increased. For d 21-35 and entire experimental period, pigs fed PSP diets had more feed intake than pigs fed NC or PC diets (p<0.05). For the whole period, ADG was improved in PSP treatments compared with NC treatment (Linear effect, p=0.05). On d 21 and d 35, digestibilities of DM and N were higher (p<0.05) for pigs fed PSP diets than pigs fed NC diet and PSP 2.5 treatment was the highest among the treatments. On d 21, digestibility of N was significantly improved in PSP treatments compared with PC treatment (p<0.05). For Exp. 2, five Duroc${\times}$Yorkshire${\times}$Landrace barrows (8.74${\pm}$0.22 kg average initial BW) were surgically fitted with a simple T-cannulas approximately 15 cm prior to the ileo-cecal junction. The experimental designs were 5${\times}$5 latin squares with pigs and periods as blocking criteria. Dietary treatments were same as Exp.1. Generally, apparent ileal digestibilities of DM and N were higher for pigs fed PSP diets than pigs fed NC or PC diets (p<0.05) and PSP 5.0 and 2.5 treatments were the highest among the treatments, respectively. Apparent ileal digestibilities of the whole amino acids were increased in PSP treatments compared with NC treatment (Quadratic effect, p${\leq}$0.05). Also, histidine, lysine and threonine digestibilities in essential amino acids and alanine, asparatic acid and glycine digestibilities in non essential amino acids were significantly higher for pigs fed PSP diets than pigs fed PC diets (p${\leq}$0.05). In conclusion, feeding processed soy protein to weanling pigs increased growth performance, nutrient digestibility and apparent ileal digestibilities of DM, N and most amino acids.