• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.12
• /
• pp.1698-1704
• /
• 2018

This paper presents a implementation of a chaotic Lorenz system for data secure communication applications. Here we have used PIC18F family-based microcontroller to generate the chaotic signal, and simulated waveform patterns confirm that the chaotic behavior of the microcontroller based discrete time chaotic Lorenz system. There are three R-2R ladder type A/D converters have been implemented for conversion of direct microcontroller digital output into analog waveform, utilizing this specific microcontroller relevant to this experiment work, microcontroller ports B, C and D have been utilized for its time waveform outputs X, Y and Z respectively. XC8 compiler used for the compilation of the program. MATLAB and PROTEUS software platforms are used for simulation. Finally, chaotic time wave forms, 2D chaotic attractors were obtained and secure communication analog waveforms were also verified by experimental measurement.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.12 no.1
• /
• pp.13-21
• /
• 2019

The content based on image retrieval makes use of features of information within image such as color, texture and share for Retrieval data. we present a novel approach for improving retrieval accuracy based on DCT Filter-Bank. First, we perform DCT on a given image, and generate a Filter-Bank using the DCT coefficients for each color channel. In this step, DC and the limited number of AC coefficients are used. Next, a feature vector is obtained from the histogram of the quantized DC coefficients. Then, AC coefficients in the Filter-Bank are separated into three main groups indicating horizontal, vertical, and diagonal edge directions, respectively, according to their spatial-frequency properties. Each directional group creates its histogram after employing Otsu binarization technique. Finally, we project each histogram on the horizontal and vertical axes, and generate a feature vector for each group. The computed DC and AC feature vectors bins are concatenated, and it is used in the similarity checking procedure. We experimented using 1,000 databases, and as a result, this approach outperformed the old retrieval method which used color information.

• KIPS Transactions on Software and Data Engineering
• /
• v.10 no.1
• /
• pp.9-18
• /
• 2021

Although Generative Adversarial Networks (GANs) have gained great popularity in computer vision and related fields, generating audio signals independently has yet to be presented. Unlike images, an audio signal is a sampled signal consisting of discrete samples, so it is not easy to learn the signals using CNN architectures, which is widely used in image generation tasks. In order to overcome this difficulty, GAN researchers proposed a strategy of applying time-frequency representations of audio to existing image-generating GANs. Following this strategy, we propose an improved method for increasing the fidelity of synthesized audio signals generated by using GANs. Our method is demonstrated on a public speech dataset, and evaluated by Fréchet Inception Distance (FID). When employing our method, the FID showed 10.504, but 11.973 as for the existing state of the art method (lower FID indicates better fidelity).

• Journal of the Korea Convergence Society
• /
• v.12 no.2
• /
• pp.221-231
• /
• 2021

This paper identify factors of migration of employees' household who work for relocated public institutions. As a factors of migration, we consider individual and household characteristics, the gravity model of distance and population and so on. Considering discrete dependant variable and structure of data, we employ the logistic multilevel model and random intercept model. The result indicates employees' who are female, 30s and 40s, higher education level(PhD) and whose spouse are unemployed tend to transfer their residential registration to new city near relocated public institution. Regarding regional variable, the distance from employee's previous residential location and number of migration of prior year are statistically significant. Also the model indicate regional economy, educational and residential environment of new city influence employee's decision for transferring residential registration.

• International Journal of Computer Science & Network Security
• /
• v.21 no.1
• /
• pp.143-151
• /
• 2021

The enormous prevalence of transferring official confidential digital documents via the Internet shows the urgent need to deliver confidential messages to the recipient without letting any unauthorized person to know contents of the secret messages or detect there existence . Several Steganography techniques such as the least significant Bit (LSB), Secure Cover Selection (SCS), Discrete Cosine Transform (DCT) and Palette Based (PB) were applied to prevent any intruder from analyzing and getting the secret transferred message. The utilized steganography methods should defiance the challenges of Steganalysis techniques in term of analysis and detection. This paper presents a novel and robust framework for color image steganography that combines Linear Congruential Generator (LCG), simulated annealing (SA), Cesar cryptography and LSB substitution method in one system in order to reduce the objection of Steganalysis and deliver data securely to their destination. SA with the support of LCG finds out the optimal minimum sniffing path inside a cover color image (RGB) then the confidential message will be encrypt and embedded within the RGB image path as a host medium by using Cesar and LSB procedures. Embedding and extraction processes of secret message require a common knowledge between sender and receiver; that knowledge are represented by SA initialization parameters, LCG seed, Cesar key agreement and secret message length. Steganalysis intruder will not understand or detect the secret message inside the host image without the correct knowledge about the manipulation process. The constructed system satisfies the main requirements of image steganography in term of robustness against confidential message extraction, high quality visual appearance, little mean square error (MSE) and high peak signal noise ratio (PSNR).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.5
• /
• pp.1610-1629
• /
• 2021

Failures frequently occurred in manufacturing machines due to complex and changeable manufacturing environments, increasing the downtime and maintenance costs. This manuscript develops a novel deep learning-based method named Multi-Domain Convolutional Neural Network (MDCNN) to deal with this challenging task with vibration signals. The proposed MDCNN consists of time-domain, frequency-domain, and statistical-domain feature channels. The Time-domain channel is to model the hidden patterns of signals in the time domain. The frequency-domain channel uses Discrete Wavelet Transformation (DWT) to obtain the rich feature representations of signals in the frequency domain. The statistic-domain channel contains six statistical variables, which is to reflect the signals' macro statistical-domain features, respectively. Firstly, in the proposed MDCNN, time-domain and frequency-domain channels are processed by CNN individually with various filters. Secondly, the CNN extracted features from time, and frequency domains are merged as time-frequency features. Lastly, time-frequency domain features are fused with six statistical variables as the comprehensive features for identifying the fault. Thereby, the proposed method could make full use of those three domain-features for fault diagnosis while keeping high distinguishability due to CNN's utilization. The authors designed massive experiments with 10-folder cross-validation technology to validate the proposed method's effectiveness on the CWRU bearing data set. The experimental results are calculated by ten-time averaged accuracy. They have confirmed that the proposed MDCNN could intelligently, accurately, and timely detect the fault under the complex manufacturing environments, whose accuracy is nearly 100%.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.15 no.3
• /
• pp.211-216
• /
• 2022

Steganography technology protects the existence of hidden information by embedding a secret message in a specific location on the cover medium. Security and resistance are strengthened by applying various hybrid methods based on encryption and steganography. In particular, techniques to increase chaos and randomness are needed to improve security. In fact, the case where the shuffling method is applied based on the discrete cosine transform(DCT) and the least significant bit(LSB) is an area that needs to be studied. I propose a new approach to hide the bit information of Hangul messages by integrating the selective shuffling method that can add the complexity of message hiding and applying the spatial domain technique to steganography. Inverse shuffling is applied when extracting messages. In this paper, the Hangul message to be inserted is decomposed into the choseong, jungseong and jongseong. It improves security and chaos by applying a selective shuffling process based on the corresponding information. The correlation coefficient and PSNR were used to confirm the performance of the proposed method. It was confirmed that the PSNR value of the proposed method was appropriate when compared with the reference value.

• KDI Journal of Economic Policy
• /
• v.45 no.3
• /
• pp.49-73
• /
• 2023

This study examines the usage status of legal services provided by lawyers targeting domestic consumers and investigates empirically how much online platforms that facilitate lawyer search and consultation can increase consumers' utility, and how much the lawyer legal service market will expand through this. To this end, this study applies a discrete choice demand model to the data collected through a conjoint survey to estimate the value of the lawyer search and consultation platform perceived by consumers, and estimates the effectiveness of the platform in expanding the market for lawyer legal services through a simulation method. As a result of the analysis, the relative value that consumers place on finding and consulting a lawyer using the online platform instead of being introduced to a lawyer by an acquaintance or searching for a lawyer offline is estimated to be about 70,414 won. It was found that the existence of lawyer search and consultation platforms could increase the market size of legal services by as little as 18.9% to as much as 70.2%. In particular, the platforms are expected to increase the accessibility of legal services to vulnerable groups.

• Journal of the Korea Computer Graphics Society
• /
• v.29 no.3
• /
• pp.93-103
• /
• 2023

The problem of reconstructing three-dimensional models of people and objects from color and depth images captured by low-cost RGB-D cameras has long been an active research area in computer graphics. Color and depth images captured by low-cost RGB-D cameras are represented as point clouds in three-dimensional space, which correspond to discrete values in a continuous three-dimensional space and require additional surface reconstruction compared to rendering using polygonal models. In this paper, we propose an effective ray-tracing based technique for visualizing point clouds rather than polygonal models. In particular, our method shows the possibility of an effective rendering method even in mobile environment which has limited performance due to processor heat and lack of battery.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.25 no.1
• /
• pp.1-13
• /
• 2023

This study examines the effects of Chinese consumers' lifestyles on pursuing the benefits and purchase intentions for athleisure wear. Chinese female consumers aged 20 to 40 in Shanghai and Chengdu, who have purchased athleisure wear were selected for a survey, and 510 questionnaires were collected. Data was analyzed using SPSS 26.0 software. Factor analysis, reliability verification, regression analysis, and discrete analysis were performed. As a result, Chinese consumers' lifestyles were classified into three categories: 'personality orientation', 'show-off orientation', and 'health orientation'. There were four benefits: 'situation pursuit', 'practicality pursuit', 'fashion style pursuit', and 'appearance pursuit' for athleisure wear. Among the lifestyle types of Chinese consumers, "individuality-oriented" showed a positive effect on "pursuit of practicality", "pursuit of situation", "pursuit of fashion style", and "pursuit of appearance" among the benefits of pursuing athleisure wear. Next, among lifestyle types, 'show-off orientation' showed a positive effect on 'individuality' and 'appearance pursuit'. Finally, among lifestyle types, 'health-oriented' showed a positive effect on 'pursuit of practicality' and 'pursuit of appearance'. On the other hand, Chinese consumers' lifestyle types of "show-off," "health-oriented," and "individuality-oriented" all exhibited a significant impact on their purchase intention for athleisure wear. According to age groups and location, there is no significant difference in terms of 'lifestyle', 'athleisure wear pursuit benefits' and 'purchase intention'. Compared married women and unmarried women, it was found that unmarried women value their health and leisure, while those with a lower their educational background, considered the lifestyle of "individuality-oriented" and "show-off-oriented", as well as "situation-pursuit", "practicality", and "fashion style pursuit".