• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.3
• /
• pp.1078-1099
• /
• 2021

Traditional image steganography hides secret information by embedding, which inevitably leaves modification traces and is easy to be detected by steganography analysis tools. Since coverless steganography can effectively resist steganalysis, it has become a hotspot in information hiding research recently. Most coverless image steganography (CIS) methods are based on mapping rules, which not only exposes the vulnerability to geometric attacks, but also are less secure due to the revelation of mapping rules. To address the above issues, we introduced camouflage images for steganography instead of directly sending stego-image, which further improves the security performance and information hiding ability of steganography scheme. In particular, based on the different sub-features of stego-image and potential camouflage images, we try to find a larger similarity between them so as to achieve the reversible steganography. Specifically, based on the existing CIS mapping algorithm, we first can establish the correlation between stego-image and secret information and then transmit the camouflage images, which are obtained by reversible sub-feature retrieval algorithm. The received camouflage image can be used to reverse retrieve the stego-image in a public image database. Finally, we can use the same mapping rules to restore secret information. Extensive experimental results demonstrate the better robustness and security of the proposed approach in comparison to state-of-art CIS methods, especially in the robustness of geometric attacks.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.7
• /
• pp.131-139
• /
• 2013

To overcome the limitations in performance and power consumption of traditional electrical interconnection based network-on-chips (NoCs), a hybrid optical network-on-chip (HONoC) architecture using optical interconnects is emerging. However, the HONoC architecture should use circuit-switching scheme owing to the overhead by optical devices, which worsens the latency unfairness problem caused by frequent path collisions. This resultingly exert a bad influence in overall performance of the system. In this paper, we propose a new task mapping algorithm for optimizing latency by reducing path collisions. The proposed algorithm allocates a task to a certain processing element (PE) for the purpose of minimizing path collisions and worst case latencies. Compared to the random mapping technique and the bandwidth-constrained mapping technique, simulation results show the reduction in latency by 43% and 61% in average for each $4{\times}4$ and $8{\times}8$ mesh topology, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.348-354
• /
• 2018

This study proposes MF (Model Filter)-based M-BDL (MF-based BIM Data Linkage), which is a model filter-based data mapping method for BIM (Building Information Modeling)-BEMS linkage. Recently, BEMS (Building Energy Management System) is actively utilizing 3D spatial information. This allows the user to intuitively manage the facility energy linked to spatial information. To use BIM data in energy management systems, it is essential to link BEMS with BIM data only in terms of the user requirements. On the other hand, if the BIM is a rich dataset and is linked as it is, the user will need to manage the unnecessary information. By mapping only the data required for BEMS in heavy BIM data through M-BDL, the BIM data can be lightened and the amount of data required for maintenance can be reduced. This technology proposes a mapping method that can link the BIM data with the filtered BIM data.

• Journal of the Society of Naval Architects of Korea
• /
• v.38 no.4
• /
• pp.56-65
• /
• 2001

The structural model of midship section is within the scope of STEP AP218. It supports to represent the ship structure, but most of shipyards and classification societies exchange the information using 2D drawings at the present. To translate the 2D information into the ship structure model of STEP AP218, we analyze the 2D midship section information of KR-TRAS of Korean Register of shipping, and include the transverse members information with the 3D model. We also define the mapping table and the mapping relationships between two data structures. With this mapping table we develop the translator for the midship section, and visualize the translated ship structure model using a STEP viewer. The ship structure model can be used to exchange information between design departments, and through the lifecycle of design, analysis, and maintenance.

• Journal of the Korean Society of School Health
• /
• v.29 no.3
• /
• pp.286-298
• /
• 2016

Purpose: The aim of this study was to identify the effects of community mapping based on volunteered Geographic Information System on smoking prevention among female middle school students. Methods: This study used a triangulation method which integrated quantitative data from a "pre-post" study on a nonequivalent control group and qualitative data from focus group interviews. Data was collected from 4 August 2015 to 10 January 2016. The experimental group (n=24) participated in community mapping along with education on smoking prevention and the control group (n=28) participated only in routine education. Both groups were measured on their knowledge and attitude related to smoking prevention through self-report questionnaires. The quantitative data was analyzed by descriptive statistics, $x^2$ analysis, and t-test using SPSS 23.0. The qualitative data was collected through focus group interviews to investigate the social-environmental effect of smoking prevention. Results: Knowledge related to smoking prevention was significantly higher (t=2.591, p=.013) in the experimental group than the control group. But attitude related to smoking prevention did not show significant differences between the two groups. When asked about their experiences of the community mapping program, it turned out to be a process where they could learn practical knowledge related to smoking prevention and experience their individual practices manifested as collective intelligence while working together with community members. The study found that community mapping had an effect on smoking prevention from a social and environmental aspect. Conclusion: To be more effective, school education on smoking prevention should be provided in connection with the community. It is also desirable to provide an opportunity where adolescents can experience discovering and solving practical problems along with their own community.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.4
• /
• pp.766-780
• /
• 1996

This paper presents a mapping scheme for parallel processing using an accurate characterization of the communication overhead. A set of objective functions is formulated to evaluate the optimality of mapping a problem graph into a system graph. One of them is especially suitable for real-time applications of parallel processing. These objective functions are different from the conventional objective functions in that the edges in the problem graph are weighted and the actual distance rather than the nominal distance for the edges in the system graph is employed. This facilitates a more accurate qualification of the communication overhead. An efficient mapping scheme has been developed for the objective functions, where two levels of assignment optimization procedures are employed: initial assignment and pairwise exchange. The mapping scheme has been tested using the hypercube as a system graph.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.6
• /
• pp.1363-1368
• /
• 2011

This paper describes an analysis on the granular noise in pixel-to-pixel mapping-based computational integral imaging. The pixel mapping-based method provides a high-resolution reconstructed images and also its computational cost is very lower than the previous back-projection-based method. In this paper, a signal model for the pixel mapping-based method is introduced, which defines and analyzes the granular noise. Computer experiments provides the granular noise properties based on the proposed signal model. The experimental results indicates that the granular noise pattern differs from that of the back-projection based method. The results is also utilized in the pixel mapping-based method.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.5C
• /
• pp.432-438
• /
• 2010

In this paper we study the effect of bit-to-symbol mappings on the convergence behavior of turbo equalizers employing low-density parity-check (LDPC) codes over high order modulations. We analyze the effective SNR of the outputs from linear minimum mean-squared error (MMSE) equalizers and the convergence property of LDPC decoding for different symbol mappings. Numerical results show that the bit-reliability (BR) mapping provides better performance than random mapping in LDPC-coded turbo equalizers over high order modulations. We also verify the effect of symbol mappings through the noise threshold and error performance.

• Journal of Korean Society for Geospatial Information Science
• /
• v.5 no.2 s.10
• /
• pp.193-205
• /
• 1997

It is required for multi-users to share massive mapping data effectively that distributed data model in the Client-Server environment is developed for the replication consistency. The existing model is not effective to the long transaction just like a mapping system, since it does not account lot consistency between GUI screen and database replications even though it emphasizes on the replication consistency. The performance of concurrency control is very important for those long transactions, especially the mapping systems. This model is to support consistency between GUI screen and replicas using display locks. It suggests consistency model improving process performance by modifying memory consistency model and optimistic concurrency control for mapping data's characteristics.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.9
• /
• pp.3672-3684
• /
• 2015

Recently, the standardization of backward compatible JPEG image coding for high dynamic range (HDR) image has been undertaken to establish an international standard called "JPEG XT." The JPEG XT consists of two layers: the base layer and the residual layer. The base layer contains tone mapped low dynamic range (LDR) image data and the residual layer contains the error signal used to reconstruct the HDR image. This paper gives the result of a study to evaluate the overall performance of tone mapping operators (TMOs) for this standard. The evaluation is performed using five HDR image datasets and six TMOs for profiles A, B, and C of the proposed JPEG XT standard. The Tone Mapped image Quality Index (TMQI) and no reference image quality assessment (NR IQA) are used for measuring the LDR image quality. The peak signal to noise ratio (PSNR) is used to evaluate the overall compression performance of JPEG XT profiles A, B, and C. In TMQI and NR IQA measurements, TMOs using display adaptive tone mapping and adaptive logarithmic mapping each gave good results. A TMO using adaptive logarithmic mapping gave good PSNRs.