• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.879-886
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• 2008

This paper addresses the analysis and the design optimization of differential interconnects for Low-Voltage Differential Signaling (LVDS) applications. Thanks to the differential transmission and the low voltage swing, LVDS offers high data rates and improved noise immunity with significantly reduced power consumption in data communications, high-resolution display, and flat panel display. We present an improved model and new equations to reduce impedance mismatch and signal degradation in cascaded interconnects using optimization of interconnect design parameters such as trace width, trace height and trace space in differential flexible printed circuit board (FPCB) transmission lines. We have carried out frequency-domain full-wave electromagnetic simulations, time-domain transient simulations, and S-parameter simulations to evaluate the high-frequency characteristics of the differential FPCB interconnects. The 10% change in trace width produced change of approximately 6% and 5.6% in differential impedance for trace thickness of $17.5{\mu}m$ and $35{\mu}m$, respectively. The change in the trace space showed a little change. We believe that the proposed approach is very helpful to optimize high-speed differential FPCB interconnects for LVDS applications.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.63-74
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• 2009

In 2005, Wang et al. discovered devastating collision attacks on the main hash functions from the MD4 family. After the discovery of Wang, many analysis results on the security of existing hash-based cryptographic schemes are presented. At CRYPTO'07, Fouque, Leurent and Nguyen presented full key-recovery attacks on HMAC/NMAC-MD4 and NMAC-MD5[4]. Such attacks are based on collision attacks on the underlying hash function, and the most expensive stage is the recovery of the outer key. At EUROCRYPT'08, Wang, Ohta and Kunihiro presented improved outer key recovery attack on HMAC/NMAC-MD4, by using a new near collision path with a high probability[2]. This improves the complexity of the full key-recovery attack on HMAC/NMAC-MD4 which proposed by Fouque, Leurent and Nguyen at CRYPTO'07: The MAC queries decreases from $2^{88}$ to $2^{72}$, and the number of MD4 computations decreases from $2^{95}$ to $2^{77}$. In this paper, we propose improved outer key-recovery attack on HMAC/NMAC-MD4 with $2^{77.1246}$ MAC queries and $2^{37}$ MD4 computations, by using divide and conquer paradigm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.47-57
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• 2003

In this paper, we firstly evaluate the resistance of the reduced 5-round version of the block cipher CIKS-1 against linear cryptanalysis(LC) and show that we can attack full-round CIKS-1 with \ulcorner56-bit key through the canonical extension of our attack. A feature of the CIKS-1 is the use of both Data-Dependent permutations(DDP) and internal key scheduling which consist in data dependent transformation of the round subkeys. Taking into accout the structure of CIKS-1 we investigate linear approximation. That is, we consider 16 linear approximations with p=3/4 for 16 parallel modulo $2^2$ additions to construct one-round linear approximation and derive one-round linear approximation with the probability P=1/2+$2^{-17}$ by Piling-up lemma. Then we present 3-round linear approximation with 1/2+$2^{-17}$ using this one-round approximation and attack the reduced 5-round CIKS-1 with 64-bit block by LC. In conclusion we present that our attack requires $2^{38}$chosen plaintexts with a probability of success of 99.9% and about $2^{67-7}$encryption times to recover the last round key.(But, for the full-round CIKS-1, our attack requires about $2^{166}$encryption times)

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.2
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• pp.144-151
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• 2022

In this paper, a 1.5V 256kb eFlash memory IP with low area DC-DC converter is designed for battery application. Therefore, in this paper, 5V NMOS precharging transistor is used instead of cross-coupled 5V NMOS transistor, which is a circuit that precharges the voltage of the pumping node to VIN voltage in the unit charge pump circuit for the design of a low-area DC-DC converter. A 5V cross-coupled PMOS transistor is used as a transistor that transfers the boosted voltage to the VOUT node. In addition, the gate node of the 5V NMOS precharging transistor is made to swing between VIN voltage and VIN+VDD voltage using a boost-clock generator. Furthermore, to swing the clock signal, which is one node of the pumping capacitor, to full VDD during a small ring oscillation period in the multi-stage charge pump circuit, a local inverter is added to each unit charge pump circuit. And when exiting from erase mode and program mode and staying at stand-by state, HV NMOS transistor is used to precharge to VDD voltage instead of using a circuit that precharges the boosted voltage to VDD voltage. Since the proposed circuit is applied to the DC-DC converter circuit, the layout area of the 256kb eFLASH memory IP is reduced by about 6.5% compared to the case of using the conventional DC-DC converter circuit.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.3
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• pp.511-525
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• 2023

As awareness of personal data protection increases, various Full Disk Encryption (FDE)-based applications are being developed that real-time encryption or use virtual drive volumes to protect data on user's PC. FDE-based applications encrypt and protect the volume containing user's data. However, as disk encryption technology advances, some users are abusing FDE-based applications to encrypt evidence associated with criminal activities, which makes difficulties in digital forensic investigations. Thus, it is necessary to analyze the encryption process used in FDE-based applications and decrypt the encrypted data. In this paper, we analyze Cryptomator and Norton Ghost, which provide volume encryption and backup functions. We analyze the encrypted data structure and encryption process to classify the main data of each application and identify the encryption algorithm used for data decryption. The encryption algorithms of these applications are recently emergin gor customized encryption algorithms which are analyzed to decrypt data. User password is essential to generate a data encryption key used for decryption, and a password acquisition method is suggested using the function of each application. This supplemented the limitations of password investigation, and identifies user data by decrypting encrypted data based on the acquired password.

• Journal of Korean Library and Information Science Society
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• v.54 no.1
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• pp.191-220
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• 2023

This research attempts to identify how members of an online community collaboratively engaged with particular social information behaviors and accomplished a defined collective action. While responding to the Sewol Ferry tragedy, MissyUSA members quickly communicated and mobilized a collective action, a full-page ad campaign in The New York Times. As a follow up study, this secondary analysis quantitatively analyzes the primary data from a previous study to explore potential relationships or underlying factors among the various identified information behaviors. In this study, nineteen of the previously identified information behaviors were analyzed using exploratory factor analysis, yielding a total of eight factors. The two major factors of shared representation/collective identification and mobilizing resources verified the findings of the previous study and are in line with the findings typical of political science. The three factors of collaborative decision-making, reaction to tension, and brainstorming were factors that maximized communication and mobilization online, without any face-to-face communication or physical organization. Three emergent factors of outburst of dissent, boycott, and planning explained how members used negative emotions of anger, referential information for boycott, and incubated next collective actions. Through exploratory factor analysis, this study verifies and expands on the findings of the previous study by identifying several emergent factors that relate to the collaborative information behaviors of an online community engaged in a collective action.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.23 no.4
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• pp.125-139
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• 2012

This paper aims to analyze the employment of graduates majoring in Library and Information Science(LIS) in K University, to identify problems in the employment of those graduates, and to propose approaches to improve employment. Among 178 graduates getting a job for five years from August 2006 to February 2011, 65% of them was employed, 32% was not employed, and 3% continued further study, The 116 graduates employed were analyzed. The results revealed that 40% are full-time employees and 60% are part-time workers. For workplace types, 29% worked in general companies and 16% worked in public libraries. 10% worked in school libraries and college libraries. Those who worked in administrative divisions in colleges or schools comprised 9%. Those who worked in public organizations and publishing companies/bookstores were 6% each. 5% worked in specialized libraries. In the case of duties, 38% were librarians. 30% were engaged in office work. Those in sales/administration were 7%. Tellers/salesperson comprised 7%. 5% worked as teaching assistants and 3% worked in the web or in IT related businesses. Those who worked in private institutes and product planning/design comprised 2% each. Teacher librarians, day care center teachers, secretaries, company newsletter reporters, soldiers and self-employed workers were 1% for each. As a result, the major congruence was around 40%. For the career which the (56) unemployed desired, 57% prepared themselves for employment and 21% prepared for Civil Service Examination. Those who prepared for teacher recruit examination and who weren't confirmed were 11% for each. The problems identified were high unemployment to 32%, higher employment as part-time workers than full-time workers, and major congruence of just around 40%. As the results, the study proposes that the national and local authorities should actively create jobs, make the students majoring in LIS have the opportunity to understand and experience jobs related to information science, develop jobs related to LIS on the academic level and provide guidance to graduates.

• 대한공업교육학회지
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• v.44 no.1
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• pp.72-93
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• 2019

The purpose of this study was to provide basic data needed to establish a system of career education which can offer necessary information for middle school students to select vocational high schools suiting to their talent and aptitude. For this, the study formulated research questions: how middle school students in Gyeonggi-do could acquire information related with entering high school; their level of understanding about general high school and vocational high school and their level of information requirement; real state and effect (level of helping them choose future school) of assistance activity for career education as provided by vocational high schools. For the analysis, the study developed a questionnaire and conducted survey for 4,459 3rd graders from 627 middle schools at Gyeonggi-do. Findings were as follows. First, methods of middle school students getting information related with entering high school turned out in the order of internet search (42.0%), consultation with family and friends (25.5%), consultation with teachers (24.0%). While, their methods of getting information related with entering vocational high school turned out in the order of briefing session by vocational high schools (39.4%), field trip to vocational high schools (24.9%), consultation with teachers from vocational high schools (15.7%). Second, the level of understanding (five points full marks) of Gyeonggi-do middle school students about high school by the type they wished to enter, and the level of information requirement (five points full marks) turned out 3.65 and 3.67 respectively for students who wished to enter general high schools, with the difference being 0.02. On the other hand, the level of understanding and that of information requirement turned out 2.92 and 3.25 respectively with the difference being 0.33, for students who wished to enter vocational high schools. Third, looking at the real state of participation of Gyeonggi-do middle school students in assistance activities for career education provided by vocational high schools, 79.4% of all students were participating. Activity with high participation ratio out of these turned out to be in the order of PR and guide book (booklet, brochure, etc.) for vocational high schools at 90.3%, briefing session prepared by vocational high schools on visit at 87.8% and video of vocational high school PR and introduction at 85.9%. The level of how these activities helped middle school students choose their high school was 3.45, showing more effect by 0.13 on students wishing to enter vocational high schools compared to those wishing to enter general high schools.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.75-95
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• 2020

With the growth of social networks, various forms of SNS have emerged. Based on various motivations for use such as interactivity, information exchange, and entertainment, SNS users are also on the fast-growing trend. Facebook is the main SNS channel, and companies have started using Facebook pages as a public relations channel. To this end, in the early stages of operation, companies began to secure a number of fans, and as a result, the number of corporate Facebook fans has recently increased to as many as millions. from a corporate perspective, Facebook is attracting attention because it makes it easier for you to meet the customers you want. Facebook provides an efficient advertising platform based on the numerous data it has. Advertising targeting can be conducted using their demographic characteristics, behavior, or contact information. It is optimized for advertisements that can expose information to a desired target, so that results can be obtained more effectively. it rethink and communicate corporate brand image to customers through contents. The study was conducted through Facebook advertising data, and could be of great help to business people working in the online advertising industry. For this reason, the independent variables used in the research were selected based on the characteristics of the content that the actual business is concerned with. Recently, the company's Facebook page operation goal is to go beyond securing the number of fan pages, branding to promote its brand, and further aiming to communicate with major customers. the main figures for this assessment are Facebook's 'OK', 'Attachment', 'Share', and 'Number of Click' which are the dependent variables of this study. in order to measure the outcome of the target, the consumer's response is set as a key measurable key performance indicator (KPI), and a strategy is set and executed to achieve this. Here, KPI uses Facebook's ad numbers 'reach', 'exposure', 'like', 'share', 'comment', 'clicks', and 'CPC' depending on the situation. in order to achieve the corresponding figures, the consideration of content production must be prior, and in this study, the independent variables were organized by dividing into three considerations for content production into three. The effects of content material, content structure, and message styles on Facebook's user behavior were analyzed using regression analysis. Content materials are related to the content's difficulty, company relevance, and daily involvement. According to existing research, it was very important how the content would attract users' interest. Content could be divided into informative content and interesting content. Informational content is content related to the brand, and information exchange with users is important. Interesting content is defined as posts that are not related to brands related to interesting movies or anecdotes. Based on this, this study started with the assumption that the difficulty, company relevance, and daily involvement have an effect on the dependent variable. In addition, previous studies have found that content types affect Facebook user activity. I think it depends on the combination of photos and text used in the content. Based on this study, the actual photos were used and the hashtag and independent variables were also examined. Finally, we focused on the advertising message. In the previous studies, the effect of advertising messages on users was different depending on whether they were narrative or non-narrative, and furthermore, the influence on message intimacy was different. In this study, we conducted research on the behavior that Facebook users' behavior would be different depending on the language and formality. For dependent variables, 'OK' and 'Full Click Count' are set by every user's action on the content. In this study, we defined each independent variable in the existing study literature and analyzed the effect on the dependent variable, and found that 'good' factors such as 'self association', 'actual use', and 'hidden' are important. Could. Material difficulties', 'actual participation' and 'large scale * difficulties'. In addition, variables such as 'Self Connect', 'Actual Engagement' and 'Sexual Sexual Attention' have been shown to have a significant impact on 'Full Click'. It is expected that through research results, it is possible to contribute to the operation and production strategy of company Facebook operators and content creators by presenting a content strategy optimized for the purpose of the content. In this study, we defined each independent variable in the existing research literature and analyzed its effect on the dependent variable, and we could see that factors on 'good' were significant such as 'self-association', 'reality use', 'concernal material difficulty', 'real-life involvement' and 'massive*difficulty'. In addition, variables such as 'self-connection', 'real-life involvement' and 'formative*attention' were shown to have significant effects for 'full-click'. Through the research results, it is expected that by presenting an optimized content strategy for content purposes, it can contribute to the operation and production strategy of corporate Facebook operators and content producers.

• Science of Emotion and Sensibility
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• v.20 no.3
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• pp.151-168
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• 2017

Current research aimed to demonstrate a way to enhance the aesthetic experience of the general public while appreciating contemporary art via online platform. Contemporary art is highly complicated and are avoided by the general public. Meanwhile, previous research confirmed that external information can lead to better aesthetic experience and appreciation of the artwork. Therefore, current research hypothesized that provision of explicit information may enhance the appreciation of contemporary artworks and aimed to demonstrate which phase of the cognitive process from Leder et al. (2004) profits from the aid of written information. Experimental environment reproduced online curating platform to reflect the current trend on exhibition. In experiment 1, subjects were presented with written information and reported how well they understood the artwork, and their willingness to visit the artwork in real life. Results revealed that written information had a positive effect on overall appreciation. Further analysis discovered a full mediation between information comprehension, artwork comprehension, and willingness to visit. In experiment 2, ARS questions and an interactive interface were added. Results indicated that information enhanced comprehension and intention to visit the artwork. Expertise, self-reference, and artistic quality which belong to later stages of Leder et al. (2004) model, acquired higher scores on information conditions. In sum, the current research illustrated clear effects of explicit information in inducing better aesthetic experience and cognitive process of contemporary artworks in online environment.