• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.6
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• pp.289-297
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• 2020

Although flash disks are being used widely instead of hard disks, it is difficult to optimize for effective utilization of flash disks because overwrite in place is impossible and the power consumption and time required for read, write, and erase operations are all different. One of these optimization issues is a cache management strategy to minimize write operations. The cache operates at two levels: an operating system equipped with flash disks and a translation layer within the flash disk. Most studies deal with the operating system-level cache strategy. In this study, we implement and analyse the DPW-LRU algorithm which is one of the recently proposed operating system cache replacement algorithms to apply to FTL, and grope with some improvements. As a result of the experiment, the DPW-LRU algorithm maintained superiority even in the FTL environment, and showed better performance with a slight improvement.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1138-1147
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• 2020

Objective: A study was made investigate factors affecting body surface temperature changes after weaning in sows, whether these can be used to aid detection of natural estrus and how they relate to subsequent reproductive performance. Methods: A total of 132 sows were selected during summer from a breeding farm, with mean parity of 3.6±2.3 and 28.5±0.9 days lactation length. Four daily measurements (6:00, 8:00, 16:00, and 18:00) of vulva (VST), udder (UST), ear base and central back skin temperatures for individual sows were taken by an infrared thermometer, continuing up to 8 days post weaning. Results: The VST obtained from sows showing estrus at 4 days post-weaning (4DPW), 5DPW, and 6DPW showed a peak at the fourth day post-weaning, but then started to decrease. The VST of sows not detected in standing heat (NDPW) remained at a lower level during the experiment, but UST was increased soon after weaning. The VST-UST temperature differences during daytime of sows that were showing behavioural standing heat on 4DPW, 5DPW, 6DPW, and 7DPW were 0.46℃±0.123℃, 0.71℃±0.124℃, 0.66℃ ±0.171℃, and 0.58℃±0.223℃, respectively. The NDPW sows had the highest UST observed, but also the lowest VST so that a more negative value of temperature difference (-0.31℃) was seen during first few days post-weaning. A total of 119 sows were observed to show standing heat and were bred. The later the estrus, the smaller the litter size (p = 0.005). Conclusion: Sows which did not show behavior indicative of stable standing heat after weaning had a VST which remained at a lower level, but the UST increased soon after weaning. Therefore, for sow heat detection under field conditions, the changes of VST and UST and difference between the two should be considered together to increase the accuracy of detection.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.387-389
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• 2003

Rational function model (RFM) is a universal sensor model for remote sensing image restitution. It is able to substitute for models of all known sensors. In this paper, RFM generation by CCD linear image models is described in detail. A principle of RFM-based 3D reconstruction and its implementation in JX4 DPW is also described. Experiments using IKONOS and SPOT5 images are carried out on JX4 DPW. Results show that RFM generated is feasible for photogrammetric restitution of CCD linear images.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.4
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• pp.3-10
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• 2015

The various studies and applications for UAVS(Unmaned Aerial Vehicle System) have been recently increased as a new technology to create 3D spatial information rapidly and accurately. UAV(Unmanned Aerial Vehicle) is economical when comparing with conventional technique, such as satellite and aerial survey, and can quickly obtain high resolution data under 5cm. This paper examined the utilizing possibility to creating 3D spatial information and analysis the compatibility the UAV data obtained by non-metric digital camera with conventional numerical photogrammetric system. The DEM and normal orthophoto is created by exclusive S/W and DPW(Digital Photogrammetry Workstation) then analysis the accuracy of created data. As a result, the accuracy of the created DEM and normal orthophoto, which is obtained by UAV then processed by DPW, is not satisfied;so it is estimated that the compatibility the UAV data with conventional numerical photogrammetric system is low.

• Korean Journal of Geomatics
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• v.1 no.1
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• pp.1-5
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• 2001

This paper presents an investigation into the operational comparison of SPOT triangulation to build GCP library by analytical plotter and DPW (digital photogrammetric workstation). GCP database derived from current SPOT images can be used to other image sensors of satellite, if any reasons, such as lack of topographic maps or GCPs. But, general formulation of a photogrammetric process for GCP measurement has to take care of the scene interpretation problem. There are two classical methods depending on whether an analytical plotter or DPW is being used. Regardless of the method used, the measurement of GCPs is the weakest point in the automation of photogrammetric orientation procedures. To make an operational comparison, five models of SPOT panchromatic images (level 1A) and negative films (level 1AP) were used. Ten images and film products were used for the five GRS areas. Photogrammetric measurements were carried out in a manual mode on P2 analytical plotter and LH Systems DPW770. We presented an approach for exterior orientation of SPOT images, which was based on the use of approximately eighty national geodetic control points as GCPs which located on the summit of the mountain. Using sixteen well-spaced geodetic control points per model, all segments consistently showed RMS error just below the pixel at the check points in analytical instrument. In the case of DPW, half of the ground controls could not found or distinguished exactly when we displayed the image on the computer monitor. Experiment results showed that the RMS errors with DPW test was fluctuated case by case. And the magnitudes of the errors were reached more than three pixels due to the lack of image interpretation capability. It showed that the geodetic control points is not suitable as the ground control points in DPW for modeling the SPOT image.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.169-174
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• 1988

An experiment was conducted to determine the feeding value of Arundinella hirat silage making by different methods ie., added starch 3%, formic acid 1% (FA), anhydrous ammonia ($NH_3$) 3%, and dried poultry waste (DPW) 3%. The samples were analyzed organic acid, cell wall constituent (NDF), cell contents (NDS), lignincutin-silica (ADL), hemicellulose (H: CHO) and in vitro dry matter digestibility (DMD) by pepsin-cellulase technique. The feeding value of silages were compared with corn siiage. The results are summarized as follows; 1.Formic acid treated to silage was lower pH(4.0), but anhydrous ammonia (8.37) and DPW added silage (8.72) were higher than that of the other treatment silages. 2.Fermentative quality of corn silage, starch, DPW, $NH_3$, control and FA treated silage were marked 100,81, 77,63,62 and 58, respectively. 3.Silage with $NH_3$, (23.57%) and DPW (10.42%) of content of protein were higher than that of other treated silages. 4.Silage with $NH_3$, was significantly lower contents of NDF, but did not ADF of among the treated silages. 5.In the contents of ADL, starch added silage was significantly decreased (p < 0.05), but did not the other treatment. 6.DMD of in vitro by pepsin-cellulase of silage with starch was increased three folds as equal to corn silage but did not increased the other treated silages. 7.Correlationship of latic acid an total acid, and NDS were a positive but lactic acid and NDF was a negative correlation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3163-3181
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• 2023

Eavesdropping attacks have seriously threatened network security. Attackers could eavesdrop on target nodes and link to steal confidential data. In the traditional network architecture, the static routing path and the important nodes determined by the nature of network topology provide a great convenience for eavesdropping attacks. To resist monitoring attacks, this paper proposes a random routing mutation defense method based on dynamic path weight (DPW-RRM). It utilizes network centrality indicators to determine important nodes in the network topology and reduces the probability of important nodes in path selection, thereby distributing traffic to multiple communication paths, achieving the purpose of increasing the difficulty and cost of eavesdropping attacks. In addition, it dynamically adjusts the weight of the routing path through network state constraints to avoid link congestion and improve the availability of routing mutation. Experimental data shows that DPW-RRM could not only guarantee the normal algorithmic overhead, communication delay, and CPU load of the network, but also effectively resist eavesdropping attacks.

• Progress in Medical Physics
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• v.10 no.2
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• pp.73-81
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• 1999

Scatter correction for single photon emission computed tomography (SPECT) plays an important role to improve image quality and quantitation. The purpose of this study was to investigate three scatter correction methods using Monte Carlo simulation. Point source and Jaszack phantom filled with Tc-99m were simulated by Monte Carlo code, SIMIND. For scatter correction, we applied three methods, Compton window (CW) method, triple window (TW) method, and dual photopeak window (DPW) method. Point sources located at various depths along the center line within a 20-cm phantom were simulated to calculate the window ratios and corresponding scatter fractions by evaluating the polynomial coefficients for DPW method. Energy windows were located in W$_1$=92-125 keV, W$_2$=124-126 keV, W$_3$=136-140 keV, W$_4$=140-141 keV, and W$_{5}$=154-156 keV. The results showed that in Jaszack phantom with cold sphere and hot sphere, the TW gave the closest contrast and percentage recovery to the ideal image, respectively, while CW overestimated and DPW underestimated the contrast of ideal one. All three scatter correction methods showed an improved image contrast. In conclusion, scatter correction is essential for improving image contrast and accurate quantification. The choice of scatter correction method should be made on the basis of accuracies and ease of implementation.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.786-791
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• 2002

Mapping systems using Satellite Imagery has not been well-established compare to conventional Arial Photograph mapping systems. In order for satellite imagery to produce a stable quality of maps, it requires to follow the standard mapping procedures. In this satellite imagery study, we proposed four methods of mapping procedures. Mapping methods were established by generating trial maps and analyzing types of input data and functions of DPW (Digital Photogrammetric Workstation). On quantitative aspect, accuracy of each steps were measured by increasing 2 GCPs each time from the minimum of 6 GCPs. In DLT, with the minimum of 10 points, RMSE is 2 pixels at most. Besides that, interpretation and stereoscopic plotting using KOMPSAT-1 imagery and other simulated imagery was performed. The tests resulted that, for KOMPSAT-1 (6.6m) stereoscopic images, the possibility of interpretation is 44.79% and possibility of stereoscopic plotting is 43.75%. In the other hand, for simulated imagery (1m), the possibility of interpretation is 60.92% and possibility of stereoscopic plotting is 55.18%.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.93-101
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• 2015

Purpose In SPECT image, scatter count is the cause of quantitative count error and image quality degradation. Thus, a wide range of scatter correction(SC) methods have been studied and this study is to evaluate the accuracy of CT based SC(CTSC) used in SPECT/CT as the comparison with existing energy window based SC(EWSC). Materials and Methods SPECT/CT images were obtained after filling air in order to acquire a reference image without the influence of scatter count inside the Triple line insert phantom setting hot rod(74.0 MBq) in the middle and each SPECT/CT image was obtained each separately after filling water instead of air in order to derive the influence of scatter count under the same conditions. In both conditions, Astonish(iterative : 4 subset : 16) reconstruction method and CT attenuation correction were commonly applied and three types of SC methods such as non-scatter correction(NSC), EWSC, CTSC were used in images filled with image. For EWSC, 9 sub-energy windows were set additionally in addition to main(=peak) energy window(140 keV, 20%) and then, images were acquired at the same time and five types of EWSC including DPW(dual photo-peak window)10%, DEW(dual energy window)20%, TEW(triple energy window)10%, TEW5.0%, TEW2.5% were used. Under the condition without fluctuations in primary count, total count was measured by drawing volume of interest (VOI) in the images of the two conditions and then, the ratio of scatter count of total counts was calculated as percent scatter fraction(%SF) and the count error with image filled with water was evaluated with percent normalized mean-square error(%NMSE) based on the image filled with air. Results Based on the image filled with air, %SF of images filled with water to which each SC method was applied is NSC 37.44, DPW 27.41, DEW 21.84, TEW10% 19.60, TEW5% 17.02, TEW2.5% 14.68, CTSC 5.57 and the most scattering counts were removed in CTSC and %NMSE is NSC 35.80, DPW 14.28, DEW 7.81, TEW10% 5.94, TEW5% 4.21, TEW2.5% 2.96, CTSC 0.35 and the error in CTSC was found to be the lowest. Conclusion In SPECT/CT images, the application of each scatter correction method used in the experiment could improve the quantitative count error caused by the influence of scatter count. In particular, CTSC showed the lowest %NMSE(=0.35) compared to existing EWSC methods, enabling relatively accurate scatter correction.