• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.156-163
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• 2012

Recently, Information Hiding Technology are becoming increasingly demanding in the field of international security, military and medical image This paper proposes data hiding technique utilizing parity checker for gray level image. many researches have been adopted LSB substitution and XOR operation in the field of steganography for the low complexity, high embedding capacity and high image quality. But, LSB substitution methods are not secure through it's naive mechanism even though it achieves high embedding capacity. Proposed method replaces LSB of each pixel with XOR(between the parity check bit of other 7 MSBs and 1 Secret bit) within one pixel. As a result, stego-image(that is, steganogram) doesn't result in high image degradation. Eavesdropper couldn't easily detect the message embedding. This approach is applying the concept of symmetric-key encryption protocol onto steganography. Furthermore, 1bit of symmetric-key is generated by the self-reference of each pixel. Proposed method provide more 25% embedding rate against existing XOR operation-based methods and show the effect of the reversal rate of LSB about 2% improvement.

• Journal of Distribution Science
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• v.14 no.4
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• pp.55-66
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• 2016

Purpose - This article aims to explore the characteristics of disaster risk distribution information in China. Also, this research attempts to analyze the findings of risk communication using case study in chronological order in terms of social amplification of risk. To achieve the purpose, the paper reviews the trends and issues of risk communication in China, with an emphasis on examining earthquakes by a chronological approach. In these regards, we hope that some relevant findings from this empirical study with cases will be able to enhance national risk communication and provide implications in Korea as well. Research design, data, and methodology - The conceptual framework of this study is theoretically based on the risk amplification model, which describes signals about risk transmitted and processed by individuals and social groups. The social amplification of risk also reflects the interactions of social groups about disaster-related risk issues, which are potential amplifiers or attenuators of communication signals. The key concept of social amplification implies that the risks pertaining to natural disasters interact with social, psychological, institutional, and cultural processes in ways that can affect public perceptions of risk. SMCRE Model is methodologically employed to examine risk communication history of China with the focus on natural disaster. Four earthquakes are selected to figure out the chronological characteristics of risk communication since 1970s. He bei Tang Shan earthquake is selected as an example disaster before 1990's, while the earthquake in Yun Nan Jiang is explored for the case study of 1990's. The earthquake in Si Chuan Wen Chuan is also examined as a example disaster of 2000's. The recent earthquake in Si Chuan Ya An Lu Shan is selected as a case of 2010s. Results - SMCRE model in this case study is operationally defined as a methodology and applied to the four earthquakes occurred in China. SMCRE model describes the exchange of risk information and is also applied to all forms of communication between stake holders. Each factor of risk communication includes source, message, channel, receiver and effect. It is notable that a big progress has been made on disaster risk communication in China for the past 40 years. We also found that highly developed information technology has enabled Chinese society to better cope with natural disaster, leading to enhanced disaster risk communication. It is mainly found from case study that the disaster risk communication of China has been involved with political situation, which derived from the change of government for the past 40 years. Conclusion - From this historical research, it can be inferred that the policies and politics of Chinese leaders have had a more critical role to play in the process of source of risk communication than those of any other countries. The results of this paper also support that the effective risk communication involves not only the improved reliability of local government as a key factor of disaster risk communication, but also is accompanied by international cooperation for substantial collaboration with stake holders.

• Korean Journal of Culture and Social Issue
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• v.29 no.1
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• pp.147-170
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• 2023

This study explored keywords and key topics by collecting posts related to 'self-Iinjury' and 'suicide' through Twitter. The study subjects were selected as posts containing related hashtags related to self-injury and suicide from October 29, 2019 to November 30, 2020. Text mining based on collected posts resulted in a total of 11 key topics: -6 related to 'self-Iinjury' and 5 related to 'suicide'. The main message in the topic is as follows. First, looking at the main messages contained in the topic, they honestly expressed self-harm and suicide experiences that are difficult to express offline online, and used SNS as a channelpath for requesting help requests. Second, there were common and discriminatory characteristics in posts related to 'self-Iinjury' and 'suicide'. Although topics related to 'self-Iinjury' mainly revealed emotional control and interpersonal functions of self-harm, messages related to 'suicide' showed more clearly messages about suicide prevention addressing and social problems. These results are meaningful in that they can understand the opinions of people who have experienced self-harm and suicide accidents and the public voice on self-harm and suicide-related issues could be better understood, and that this study seeks for effective self-harm and suicide prevention and intervention measures for self-harm and suicide issues.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.71-76
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• 2014

There is to be virtually impossible to solve the very large digits of prime number p and q from composite number n=pq using integer factorization in typical public-key cryptosystems, RSA. When the public key e and the composite number n are known but the private key d remains unknown in an asymmetric-key RSA, message decryption is carried out by first obtaining ${\phi}(n)=(p-1)(q-1)=n+1-(p+q)$ and then using a reverse function of $d=e^{-1}(mod{\phi}(n))$. Integer factorization from n to p,q is most widely used to produce ${\phi}(n)$, which has been regarded as mathematically hard. Among various integer factorization methods, the most popularly used is the congruence of squares of $a^2{\equiv}b^2(mod\;n)$, a=(p+q)/2,b=(q-p)/2 which is more commonly used then n/p=q trial division. Despite the availability of a number of congruence of scares methods, however, many of the RSA numbers remain unfactorable. This paper thus proposes an algorithm that directly and immediately obtains ${\phi}(n)$. The proposed algorithm computes $2^k{\beta}_j{\equiv}2^i(mod\;n)$, $0{\leq}i{\leq}{\gamma}-1$, $k=1,2,{\ldots}$ or $2^k{\beta}_j=2{\beta}_j$ for $2^j{\equiv}{\beta}_j(mod\;n)$, $2^{{\gamma}-1}$ < n < $2^{\gamma}$, $j={\gamma}-1,{\gamma},{\gamma}+1$ to obtain the solution. It has been found to be capable of finding an arbitrarily located ${\phi}(n)$ in a range of $n-10{\lfloor}{\sqrt{n}}{\rfloor}$ < ${\phi}(n){\leq}n-2{\lfloor}{\sqrt{n}}{\rfloor}$ much more efficiently than conventional algorithms.

• Journal of Distribution Science
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• v.9 no.2
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• pp.73-81
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• 2011

This study is designed to examine the effects of information source effects of the word mouth have on the formed expectations for the private institution and to explore the formed expectations' effects on the actual sales of the educational service. Moreover, its purpose is in analyzing what medication effects the pre-conceived expectation has on selecting the educational service. After testing hypothesis, the results showed that the source effects of the information from word of mouth had a significant effect on the expectation factors, in terms of expertise, similarity, likability and familiarity expectation factors. However, it was found that effect was not significant for the truthfulness. The significant result was found on the expectation factors before visiting the private institution on selecting educational service, indicating a positive effect. As for the influence of source of the word of mouth information on selecting educational service, the results from the mediation effects of the expectation factors on selecting the educational service showed that for expectation factors, expertise had the partial mediation effect, truthfulness, perfect mediating effect, similarity, partial mediation effect, likability, perfect mediating effect, and familiarity, perfect mediating effect. A test of the mediating role of attribute expectations in the influence of WOM message source attributes on educational services choices showed the following: 1) It was proven that attribute expectations played a partial mediating role in the influence of expertise and similarity, respectively, on educational services choices. 2) On the influence of trustworthiness, likability, and familiarity on educational services choices, respectively, attribute expectations had a full mediation effect. This research differs from the previous ones, which focused only on consumer satisfaction with educational services offered by private educational institutions in that it covers not only the influences of both WOM source attributes and key component factors of educational services on both educational services choices and satisfaction with such services but also the influence of WOM source attributes on attribute expectations prior to the first visit to a particular private educational institutions, and in turn the influence of such attribute expectations on educational services choices. Most particularly, the significance of this study lies in the fact that in an effort to more clearly explain the causal relationship between WOM source effects and educational services choices a test of the mediating role of attribute expectations was conducted. Although the research seems simple, some theoretical implications can be drawn as follows: WOM message source effects on educational services choices were positive and moreover these positive impacts are likely to be reinforced by means of the mediating variable of attribute expectations.

• Journal of Distribution Science
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• v.12 no.4
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• pp.55-63
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• 2014

Purpose - Brands and products often play key roles in enabling consumers to experience a good attitude, resulting in mentally enacting a specific prototype and reliving the experience by retelling a specific story. Brand storytelling can function as an important tool for managing the brand. To successfully apply a firm's brand storytelling, it is important to prove the effectiveness of storytelling. Therefore, by utilizing the research of Escalas (1998) and Fog et al. (2005), a list of measurements for storytelling component quality (SCQ) was applied. In addition, customer attitudes toward brand storytelling were tested. In particular, if customers encounter a dynamic and interesting story, although the brand is not widely known, they can be in communion with the brand and establish an emotional connection (Hill, 2003). Thus, brand reputation was divided into two levels (high vs. low), and the difference in effectiveness between storytelling component quality and consumers' advertisement attitude, brand attitude, and purchasing intention was examined. Research design, data, and methodology - By using the measurement list used in Choi, Na, and Hwang (2013), 12 categories in the level of message quality, conflict quality, character quality, and plot quality were measured. In addition, categories of brand reputation, advertisement attitude, brand attitude, and purchasing intention were measured. The study was based on 181 final survey samples targeting undergraduate and graduate students in Gwangju Metropolitan City. Results - Consumer responses toward storytelling were researched in the context of brand characteristics or product attributes, such as brand reputation, differentiated from extant simple effects of storytelling. Some brands with high reputation enjoy a halo effect due to prior learning, while other brands with comparatively low reputation have trouble generating positive responses despite attempts to enhance the level of reputation or induce favorable attitudes. Although not all due to the component quality of storytelling, the case of brands with low reputation exerted more positive impact on consumer attitudes than did brands with high reputation. As mentioned earlier, consumer evaluation of the component quality of storytelling was categorized into advertising attitudes, brand attitudes, and purchase intention for this study; this provides managerial implications in other ways. The results imply that an effective application of storytelling could be an important emotional tool for the development of both brands with low brand awareness and of well-known brands. Finally, this study serves to increase consumers' understanding and ability in interpreting brand stories that marketers tell about themselves, as well as to highlight differential experiences with products by level of brand hierarchy. Conclusions - This research aimed to provide an objective guideline for storytelling component quality while considering brand awareness. Thus, brand reputation was considered for proving the baseline effectiveness of storytelling, and this study provided directions for strategic establishment of storytelling. Based on this, we conclude that in further studies, it will be necessary to systematically manage brand story by considering other situation variables and various story patterns, and studying their differences.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.92-109
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• 2015

Broadcast encryption is a cryptographic primitive that allows a sender to securely broadcast a message to a set of receivers. The most influential broadcast encryption system was proposed in 2001 by Naor, Naor, Lotspiech, based on a pseudo-random generator and the Subset Difference (SD) method. In this paper, we suggest a new broadcast encryption system that is based on secret sharing and SD methods. On an efficiency aspect, our system achieves O(r) transmission cost, O($log^2n$) storage cost, and O(1) computational cost for the number n of users and the number r of revoked users. Compared to O(log n) computational cost in the previous SD method, our system has the advantage that it needs only constant-sized computational cost for decryption, regardless of the number n or r. On a security aspect, our system can achieve tighter security reduction than the previous SD method and the gap of security loss is about O(n log n). Moreover, our result shows that it is possible to give the effect of the SD method while using an information-theoretically secure key distribution technique as in the Complete Subtree method.

• Cartoon and Animation Studies
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• s.34
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• pp.167-195
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• 2014

A handwritten poster named "How are you, really?" appeared on December 10, 2013. And other handwritten posters sympathizing with it followed in places and are on everyone's lips hotly through internet and SNS. Such a social phenomenon is delivered to readers as a form of article in different meanings according to the viewpoint of each press. It is also delivered to readers as a material for delivering a meaning of a specific case in four panel comics strips and satirical cartoon of newspaper. This is because that comic strips of the press are now having a power to enlighten readers on the key point of a case easily and intuitively together with catharsis from the position of meditating the world. Notwithstanding differences depending on the viewpoints of the press or cartoonist, four panel comics strips and satirical cartoon on the newspaper are fulfilling their social role having their own voice. Of the genres of comic strips, social role of the comics of the press can be divided largely into two things. First, they actively intervene in social phenomena. In other words, comics of the press make their position and insistence on social phenomena clearly by exaggeration and emphasis. Second, they persuade or enlighten readers by concrete directions, which means that comics of the press make reader with similar viewpoint emphasize by delivering a clear message. This study aims to assert that comic strips are the most important medium with social role and responsibility. As part of studies on the social role of comics, this study wish that comic strips can be able to deviate from vicious circle of being socially condemned for reason of negative portion.

• Safety and Health at Work
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• v.10 no.4
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• pp.452-460
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• 2019

Background: Monitoring and control of PM_2.5 are being recognized as key to address health issues attributed to PM_2.5. Availability of low-cost PM_2.5 sensors made it possible to introduce a number of portable PM_2.5 monitors based on light scattering to the consumer market at an affordable price. Accuracy of light scatteringe-based PM_2.5 monitors significantly depends on the method of calibration. Static calibration curve is used as the most popular calibration method for low-cost PM_2.5 sensors particularly because of ease of application. Drawback in this approach is, however, the lack of accuracy. Methods: This study discussed the calibration of a low-cost PM_2.5-monitoring device (PMD) to improve the accuracy and reliability for practical use. The proposed method is based on construction of the PM_2.5 sensor network using Message Queuing Telemetry Transport (MQTT) protocol and web query of reference measurement data available at government-authorized PM monitoring station (GAMS) in the republic of Korea. Four machine learning (ML) algorithms such as support vector machine, k-nearest neighbors, random forest, and extreme gradient boosting were used as regression models to calibrate the PMD measurements of PM_2.5. Performance of each ML algorithm was evaluated using stratified K-fold cross-validation, and a linear regression model was used as a reference. Results: Based on the performance of ML algorithms used, regression of the output of the PMD to PM_2.5 concentrations data available from the GAMS through web query was effective. The extreme gradient boosting algorithm showed the best performance with a mean coefficient of determination (R²) of 0.78 and standard error of 5.0 ㎍/㎥, corresponding to 8% increase in R² and 12% decrease in root mean square error in comparison with the linear regression model. Minimum 100 hours of calibration period was found required to calibrate the PMD to its full capacity. Calibration method proposed poses a limitation on the location of the PMD being in the vicinity of the GAMS. As the number of the PMD participating in the sensor network increases, however, calibrated PMDs can be used as reference devices to nearby PMDs that require calibration, forming a calibration chain through MQTT protocol. Conclusions: Calibration of a low-cost PMD, which is based on construction of PM_2.5 sensor network using MQTT protocol and web query of reference measurement data available at a GAMS, significantly improves the accuracy and reliability of a PMD, thereby making practical use of the low-cost PMD possible.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.91-98
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• 2004

This study focuses on the development of dynamic assignment for evaluation and application for dynamic route guidance strategy. Travelers are classified according to information contents which they received pre/on trip. The first group have no traffic information, so they travel with fixed route. The second group have real-time shortest path and travel according to it. The last group have car navigation system or individual method(cellular phone, PDA-two way communication available) for traffic information on trip. And then they are assigned in accordance with the proposed multiclass dynamic assignment model. At this time the last group is gotten under control with DFS(decentralized feedback strategy). In use of this Process we expect that various traffic information strategy can be tested and also be the key factor for success of ITS, location of VMS(variable message sign), cycle of information, area of traffic information, etc).