• Journal of Digital Convergence
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• v.18 no.2
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• pp.1-12
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• 2020

This study aimed to select and evaluate policy priorities for the expansion of public and semi-public systems for coastwise passenger transport services. For research methodology, the Consistent Fuzzy Preference Relations (CFPR) method was used to effectively extract expert knowledge. First, the result of the analysis on policy tasks for expanding the semi-public system for coastwise passenger transport services showed that "the establishment of public transportation fare system" was the most important task at 0.160. Second, "conversion of the subsidiary routes to a public system by the central government" was ranked next at the importance of 0.136. The factor named "support through proper allocation of budgets between national and local governments" are ranked third (0.119). The results of this study have practical implications in that it proposed the policy priorities for the expansion of the public semi-public systems for coastwise passenger transport services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.7
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• pp.2703-2718
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• 2015

Nowadays, public cloud storage is gaining popularity and a growing number of users are beginning to use the public cloud storage for online data storing and sharing. However, how the encrypted data stored in public clouds can be effectively shared becomes a new challenge. Proxy re-encryption is a public-key primitive that can delegate the decryption right from one user to another. In a proxy re-encryption system, a semi-trusted proxy authorized by a data owner is allowed to transform an encrypted data under the data owner's public key into a re-encrypted data under an authorized recipient's public key without seeing the underlying plaintext. Hence, the paradigm of proxy re-encryption provides a promising solution to effectively share encrypted data. In this paper, we propose a new certificate-based proxy re-encryption scheme for encrypted data sharing in public clouds. In the random oracle model, we formally prove that the proposed scheme achieves chosen-ciphertext security. The simulation results show that it is more efficient than the previous certificate-based proxy re-encryption schemes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.1-12
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• 2008

Recently, the roll of bus transit is critical more than before because of the dramatical increase in congestions and oil prices, but bus companies seriously encounter into vicious circle situation such as decrease in passenger demand, income reduction, and revenue deterioration. To tackle this, major metropolitan cities, Seoul, Busan, DaeGu, etc. have introduced a semi-public system to reinforce public function of bus. However, it was resulted in side effects that the main board of bus company did not control theirselves voluntarily, and the management and control of public sectors on bus become very important elements. In this research, the types, limitations, and development of operation-management items, and a methodology for analysis, and changes in those trends are addressed under semi-public system using APTS data. Conclusively, this study could be one of the useful application results and alternatives for the operation-management policy of bus transit-related agencies.

• The Journal of Information Systems
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• v.21 no.2
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• pp.45-71
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• 2012

The purpose of the study is to propose the plans promoting IS acceptances under the circumstances where the IS usage is semi-mandatory. Since the IS usage is critical to secure the organization's competitiveness, many researchers have endeavored to investigate the factors in promoting IS acceptance. While TAM(Technology Acceptance Model) has been generally applied under the voluntary circumstance, under the mandatory circumstance did many researchers come to realized the limit of applying the TAM on IS acceptance. This resulted in various research trials to identify the IS acceptance under the mandatory circumstance. However, no research to promoting IS acceptance under the recommend circumstance where the corresponding users are recommend to the IS rather than alternative systems exits. The study applied the concept of switching costs to the research model, identified users' acceptance variations, and finally proposed the promotion plans for IS acceptance. The findings illustrate that IS dependence levels tend to be increased when both user satisfactions from a psychological perspective and monetary benefits from an economic perspective make the switching costs higher. The study stresses that organizations should provide information systems which reduce users' time, costs, and endeavors in performing their tasks, rather than require to use them by compulsion.

• The Korean Journal of Applied Statistics
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• v.33 no.4
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• pp.379-393
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• 2020

A terminal event such as death may censor an intermediate event such as relapse, but not vice versa in semi-competing risks data, which is often seen in medicine, public health, and epidemiology. We propose a Weibull regression model with a normal frailty to analyze semi-competing risks data when all three transition times of the illness-death model are possibly interval-censored. We construct the conditional likelihood separately depending on the types of subjects: still alive with or without the intermediate event, dead with or without the intermediate event, and dead with the intermediate event missing. Optimal parameter estimates are obtained from the iterative quasi-Newton algorithm after the marginalization of the full likelihood using the adaptive importance sampling. We illustrate the proposed method with extensive simulation studies and PAQUID (Personnes Agées Quid) data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.302-322
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• 2021

In the system of ciphertext policy attribute-based encryption (CP-ABE), only when the attributes of data user meets the access structure established by the encrypter, the data user can perform decryption operation. So CP-ABE has been widely used in personal health record system (PHR). However, the problem of key abuse consists in the CP-ABE system. The semi-trusted authority or the authorized user to access the system may disclose the key because of personal interests, resulting in illegal users accessing the system. Consequently, aiming at two kinds of existing key abuse problems: (1) semi-trusted authority redistributes keys to unauthorized users, (2) authorized users disclose keys to unauthorized users, we put forward a CP-ABE scheme that has authority accountability, user traceability and supports arbitrary monotonous access structures. Specifically, we employ an auditor to make a fair ruling on the malicious behavior of users. Besides, to solve the problem of user leaving from the system, we use an indirect revocation method based on trust tree to implement user revocation. Compared with other existing schemes, we found that our solution achieved user revocation at an acceptable time cost. In addition, our scheme is proved to be fully secure in the standard model.

• Journal of the Korean Applied Science and Technology
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• v.40 no.3
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• pp.435-452
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• 2023

This study was conducted for a systematic literature review according to the period, subject, and research method for 198 papers related to tattoo and semi-permanent makeup published from 1979 to 2022. By period, it was divided into the first period (1979-1994), the second period (1995-2005), the third period (2006-2012), and the fourth period (2013-2022). In the first period, research on health and medical aspects was the main focus, and in the second period, studies in various aspects such as art and culture began to appear. The 3rd period was characterized by increased research on semi-permanent makeup, and the 4th period was marked by a rapid increase in research on tattoos and semi-permanent makeup. By research topic, it was analyzed by dividing it into health and medical care, beauty, fashion and art, society and culture, law and system. As a result, cosmetic studies were most actively conducted to identify consumers' preferences and perceptions, and health and medical studies were the second most common. Recently, as the need for legalization has increased, studies related to laws and systems have increased rapidly, and studies on culture, history, and fashion have also been conducted. By research method, survey research were used the most, and various methods such as literature study and case studies were also used. This study is expected to further promote follow-up research in the future and contribute to the development of related industries.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1791-1796
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• 2005

Semi-shield tunneling is one of the propulsion construction methods used to lay pipes underground between two pits named 'entrance' and 'destination', respectively. Usually a simple composition, such as 'a fiducial target at the entrance+a total station (TS)+a target on the machine', is used to confirm the planned course. However, unavoidable curved sections are present in small-sized pipe lines, which are laid after implementation of a road system, for public works such as waterworks, sewer, electrical power, and gas and communication networks. Therefore, if the planned course has a curved section, it is difficult to survey the course with the abovementioned simple composition. This difficulty could be solved by using the multiple total stations (MTS), which attaches the cross type linear LED target to oneself. The MTS are disposed to where each TS can detect the LED target at the other TS or the base point or the machine. And the accurate relative positions between each MTS and target are calculated from measured data. This research proposes the relative and absolute coordinate calculation algorithm by using three MTS to measure a curved course with 20m curvature at 30m maximum distance, and verifies the algorithm experimentally.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.3962-3980
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• 2019

To deal with single sample face recognition, this paper presents a patch based semi-supervised linear regression (PSLR) algorithm, which draws facial variation information from unlabeled samples. Each facial image is divided into overlapped patches, and a regression model with mapping matrix will be constructed on each patch. Then, we adjust these matrices by mapping unlabeled patches to $[1,1,{\cdots},1]^T$. The solutions of all the mapping matrices are integrated into an overall objective function, which uses ${\ell}_{2,1}$-norm minimization constraints to improve discrimination ability of mapping matrices and reduce the impact of noise. After mapping matrices are computed, we adopt majority-voting strategy to classify the probe samples. To further learn the discrimination information between probe samples and obtain more robust mapping matrices, we also propose a multistage PSLR (MPSLR) algorithm, which iteratively updates the training dataset by adding those reliably labeled probe samples into it. The effectiveness of our approaches is evaluated using three public facial databases. Experimental results prove that our approaches are robust to illumination, expression and occlusion.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.4
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• pp.41-46
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• 2004

This paper presents a new semi- systolic architecture for $AB^2$ operation. First of all the previous architecture proposed by Lee et al. is analysed and then we present a new algorithm and it's architecture for $AB^2$ operation based on AOP (all one polynomial) to solve the shortcomings in the architecture. Proposed architecture has an efficient configuration than other previous architectures. It is useful for implementing the exponentiation architecture, which is the core operation in public-key cryptosystems.