• Journal of KIISE:Software and Applications
• /
• v.37 no.8
• /
• pp.599-610
• /
• 2010

Color laser printers are nowadays abused to print or forge official documents and bills. Identifying color laser printers will be a step for media forensics. This paper presents a new method to identify color laser printers with printed color images. Since different printer companies use their own printing process, each of printed papers from different printers has a little different invisible noise. After the wiener-filter is used to analyze the invisible noises from each printer, we extract some features from these noises by calculating a gray level co-occurrence matrix. Then, these features are applied to train and classify the support vector machine for identifying the color laser printer. In the experiment, we use total 2,597 images from 7 color laser printers. The results prove that the presented identification method performs well using the noise features of color printed images.

• KIISE Transactions on Computing Practices
• /
• v.23 no.7
• /
• pp.417-423
• /
• 2017

Recently, many embedded devices that have the computing capability required for deep learning have become available; hence, many new applications using these devices are emerging. However, these embedded devices have an architecture different from that of PCs and high-performance servers. In this paper, we propose a method that improves the performance of deep-learning framework by considering the architecture of an embedded device that shares memory between the CPU and the GPU. The proposed method is implemented in Caffe, an open-source deep-learning framework, and is evaluated on an NVIDIA Jetson TK1 embedded device. In the experiment, we investigate the image recognition performance of several state-of-the-art deep-learning networks, including AlexNet, VGGNet, and GoogLeNet. Our results show that the proposed method can achieve significant performance gain. For instance, in AlexNet, we could reduce image recognition latency by about 33% and energy consumption by about 50%.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.12
• /
• pp.2820-2827
• /
• 2015

HSMS communication system using low-cost micro controller units(MCUs) is an essential technique for online semiconductor equipment system developments. It is intended as an alternative to SEMI E4 (SECS-I) for applications where higher speed communication is needed and the facilitated hardware setup is convenient. In this paper, an HSMS communication system using low-cost MCUS is designed and implemented. Using a MCU with a low price but high-performance as a main board, a module which processes HSMS communication is designed, and a circuit is designed to process BCR independently with a microminiature MCU. To convert tag data which is recognized from BCR into data based on HSMS communication protocol, SECS-II message is designed. Lastly, an HSMS communication system is implemented based on these designs. A low-cost HSMS communication module developed in this study can be applied in realtime monitoring and controlling system for semiconductor processes.

• Journal of KIISE:Computing Practices and Letters
• /
• v.12 no.5
• /
• pp.286-299
• /
• 2006

Due to the continuing technical progress in the capabilities of modeling, simulation, and sensor devices, huge volume data with very high resolution are common. In scientific visualization, various interactive real-time techniques on high performance parallel computers to effectively render such large scale volume data sets have been proposed. In this paper, we present a mobile volume visualization system that consists of mobile clients, gateways, and parallel rendering servers. The mobile clients allow to explore the regions of interests adaptively in higher resolution level as well as specify rendering / viewing parameters interactively which are sent to parallel rendering server. The gateways play a role in managing requests / responses between mobile clients and parallel rendering servers for stable services. The parallel rendering servers visualize the specified sub-volume with rendering contexts from clients and then transfer the high quality final images back. This proposed system lets multi-users with PDA simultaneously share commonly interesting parts of huge volume, rendering contexts, and final images through CSCW(Computer Supported Cooperative Work) mode.

• Journal of KIISE:Computing Practices and Letters
• /
• v.10 no.5
• /
• pp.385-393
• /
• 2004

Cluster systems have been widely used for solving problems in various application domains, and regarded as useful high performance computing resources. As the number of cluster system user is increasing, it is no less important to maintain stable operation than to improve cluster system performance. Although hardware preventive maintenance is important for keeping normal operation, the testing tool which can be used for general cluster systems during maintenance has received little attention. In this Paper, considering hardware Preventive maintenance, we suggest a testing tool for hardware of cluster system. The cluster system testing tool which is named CTS(Cluster system Test Suite) has two check routines; one for memory, and the other for NIC respectively. The CTS is designed to support the common features of general cluster systems and all the Jobs such as setting test conditions to querying the results can be done entirely within an integrated GUI environment. CTS is used as the testing tool for two kinds of cluster systems during maintenance, and the experimental results show that CTS reports useful information for cluster systems management.

• KIISE Transactions on Computing Practices
• /
• v.22 no.10
• /
• pp.488-496
• /
• 2016

In this paper, we introduce a virtual reality interface for scientific visualization applications. Our VR interface is based on an open-source framework called VR Juggler. Although VR Juggler has its own advantages, it lacks some of the important functionalities needed for practical applications - event handling, synchronization and data sharing among cluster nodes, to name a few. We explain how these issues are resolved while developing the VR interface. Also, a new interface with a smart device, which replaces the virtual reality input device, is introduced. Finally, system usability test results are provided to prove the effectiveness of the proposed interfaces.

• Journal of Broadcast Engineering
• /
• v.15 no.6
• /
• pp.853-867
• /
• 2010

Recently, thumbnail techniques are required to index a high-performance video at digital convergence-based multimedia service like IPTV and DMB. Therefore a thumbnail extraction method in H.264/AVC bitstreams has been proposed. However, thumbnail quality deterioration problem at converting the general equation of spatial domain to frequency domain which is generated by not considering about H.264/AVC transform and quantization processing and rounding-off operation in intra prediction. In this paper, we propose a new thumbnail extraction method in H.264/AVC bitstreams. The proposed scheme is based on H.264/AVC core-transform for a thumbnail extraction in frequency domain, and probability theory, intra rounding-off error compensation. Through the implementation and performance evaluation, the subjective quality difference between the output of our scheme and the output of reference decoder is negligible and better than the conventional method, and moreover PSNR gain by up to 8.66 dB.

• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.12
• /
• pp.968-972
• /
• 2009

The multi-core processors are being widely exploited by many high-end systems. With significant advances in processor architecture, the network band-width required on the high-end systems is increasing drastically. It is therefore highly desirable to manage multiple cores efficiently to achieve high network band-width with minimum resource requirements. Modern operating systems, however, still have significant design and optimization space to leverage the network performance over multi-core systems. In this paper, we suggest a novel networking process scheduling scheme, which decides the best processor affinity of networking processes based on the processor cache layout, communication intensiveness, and processor loads. The experimental results show that the scheduling scheme implemented in the Linux kernel can improve the network bandwidth and the effectiveness of processor utilization by 20% and 59%, respectively.

• KIISE Transactions on Computing Practices
• /
• v.23 no.3
• /
• pp.171-176
• /
• 2017

Recently, several information-technology research projects such as those for high-performance computing, the cloud service, and the DevOps methodology have been advanced to develop the efficiency of satellite data-processing systems. In March 2019, the Geostationary Ocean Color Imager II (GOCI-II) will be launched for its predictive capability regarding marine disasters and the management of the fishery environment; moreover, the GOCI-II Ground Segment (G2GS) system for data acquisition/processing/storing/distribution is being designed at the Korea Ocean Satellite Center (KOSC). The G2GS is composed of the following six functional subsystems: data-acquisition subsystem (DAS), data-correction subsystem (DCS), precision-correction subsystem (PCS), ocean data-processing subsystem (ODPS), data-management subsystem (DMS), and operation and quality management subsystem (OQMS). The G2GS will enable the real-time support of the GOCI-II ocean-color data for government-related organizations and public users.

• KIISE Transactions on Computing Practices
• /
• v.21 no.12
• /
• pp.762-767
• /
• 2015

An Internet of Things (IoT) is a system where various "things" are connected to each other via a wired/wireless network, and where information is gathered, processed, and interchanged/shared. One of the important actors in IoT is a mobile IoT device (such as a smartphone or tablet). These devices tend to consume a large amount of power in order to provide various high performance application services; however, as the devices cannot be supplied with power all the time, efficient power management is necessary. Power management of mobile IoT devices involves complex relationships between various entities such as application processors (APs), HW modules inside/outside AP, operating systems, mobile IoT platforms, and applications. In order to develop power-efficient mobile IoT devices, a method is needed to systematically analyze these relationships and manage power based on a clear understanding of them. To address this problem, software engineering principles for the development of power-efficient mobile IoT devices are presented in this paper. The feasibility of the proposed principles have been validated in the domain of smartphone camera power management.