• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.6
• /
• pp.97-106
• /
• 2003

The important factor in Public-Key Infrastructure is the authentication to correspondent. We receive the digital certificate for authentication between each other, and then we check the existence of validity on the certificate by Certification Revocation List(CRL). But, To use CRL is the scheme used in offline status. So, it is impossible to refer to the latest information and the CRL scheme which is used after downloading is variously unsuitable to getting bigger of the CRL size as time goes on. Therefore, we prefer OCSP(Online Certificate Status Protocol) used in online to CRL used in offline. Consequently, we propose the scheme which provides the request of fast verification in case of requesting the verification on the certificate by owning the same update information to Certificate Registry and distributed OCSP.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.121-131
• /
• 2022

We look at the initial stage of Meta (previous Facebook)'s new metaverse platform and investigate its platform design in pre-launch and ignition life stage. From the Rocket Model (RM)'s theoretical logic, the results reveal that Meta firstly focuses on investing in key content developers by acquiring virtual reality (VR), video, music content firms and offering production support platform of the augmented reality (AR) content, 'Spark AR' last three years (2019~2021) for attracting high-potential developers and users. In terms of three matching criteria, Meta develops an Artificial Intelligence (AI) powered translation software, partners with Microsoft (MS) for cloud computing and AI, and develops an AI platform for realistic avatar, MyoSuite. In 'connect' function, Meta curates the game concept submitted by game developers, welcomes other game and SNS based metaverse apps, and expands Horizon Worlds (HW) on VR devices to PCs and mobile devices. In 'transact' function, Meta offers 'HW Creator Funding' program for metaverse, launches the first commercialized Meta Avatar Store on Meta's conventional SNS and Messaging apps by inviting all fashion creators to design and sell clothing in this store. Mata also launches an initial test of non-fungible token (NFT) display on Instagram and expands it to Facebook in the US. Lastly, regarding optimization, especially in the face of recent data privacy issues that have adversely affected corporate key performance indicators (KPIs), Meta assures not to collect any new data and to make its privacy policy easier to understand and update its terms of service more user friendly.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.5
• /
• pp.1634-1652
• /
• 2022

Due to the increasing need for data sharing in the age of big data, how to achieve data access control and implement user permission revocation in the blockchain environment becomes an urgent problem. To solve the above problems, we propose a novel blockchain-based data sharing scheme (BDSS) with fine-grained access control and permission revocation in this paper, which regards the medical environment as the application scenario. In this scheme, we separate the public part and private part of the electronic medical record (EMR). Then, we use symmetric searchable encryption (SSE) technology to encrypt these two parts separately, and use attribute-based encryption (ABE) technology to encrypt symmetric keys which used in SSE technology separately. This guarantees better fine-grained access control and makes patients to share data at ease. In addition, we design a mechanism for EMR permission grant and revocation so that hospital can verify attribute set to determine whether to grant and revoke access permission through blockchain, so it is no longer necessary for ciphertext re-encryption and key update. Finally, security analysis, security proof and performance evaluation demonstrate that the proposed scheme is safe and effective in practical applications.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.11
• /
• pp.589-598
• /
• 2007

In the group communication which has multiple data streams and various access privileges, it is necessary to provide group access control. The group members having the same access privilege are classified into one class, and the classes form a hierarchy based on the access relations. Then each class is assigned to a secret key. In the previous schemes, a single logical key graph is constructed from the hierarchy and each member always holds all secret keys of the classes he can access in the proactive manner. Thus, higher-privileged members hold more keys then lower-privileged members. However, if the hierarchy is large, each member manages too many keys and the size of multicast message in rekeying increases in proportion to the size of the hierarchy. Moreover, most of the members access a small portion of multiple data streams simultaneously. Therefore, it is redundant to receive rekeying message and update the keys in which he is not currently interested. In this paper, we present a new key management scheme that takes a reactive approach in which each member obtains the key of a data stream only when he wants to access the stream. Each member holds and updates only the key of the class he belongs. If he wants to get the key of other class, he derives it from his key and the public parameter. Proposed scheme considerable reduces the costs for rekeying, especially in the group where access relations are very complex and the hierarchy is large. Moreover, the scheme has another advantage that it easily reflects the change of access relations.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.81-84
• /
• 2001

A real time optimization algorithm for fed-batch cultures of recombinant yeast to determine the optimal substrate feed rate profile has been developed. Its development involved four key steps: (1) development of reliable adaptive model. (2) development of optimization algorithm. (3) design of on-line model update algorithm to be incorporated into the optimization algorithm and (4) experimental validation. A recombinant Saccharomyces cerevisiae producing human parathyroid hormone (hPTH) was chosen as the model strain. It was found to be very successful in maintaining cell growth and galactose consumption at leigh levels, thus resulting in significant improvements in the productivity (up to 2.1 times) and intact hPTH concentration (up to 1.5 times) compared with the case of an intermittent glucose and galactose, or galactose feeding.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.6
• /
• pp.2395-2403
• /
• 2014

As the recurrence and mortality rates of bladder cancer are high, research is needed to find suitable biomarkers for early detection, evaluation of prognosis, and surveillance of drug responses. We performed a computerized search of the Medline/PubMed databases with the key words bladder cancer, biomarker, early detection, prognosis and drug response. Several markers were identified at DNA, RNA and protein levels with different sensitivities and specificities. Only a few of the potential bladder cancer biomarkers have been approved for clinical use. Efforts now should be concentrated on finding a panel of markers with acceptable sensitivity and specificity for early detection of bladder cancer.

• Clinical and Experimental Pediatrics
• /
• v.59 no.11
• /
• pp.432-439
• /
• 2016

Asthma is recognized as a complex disease resulting from interactions between multiple genetic and environmental factors. Accumulating evidence suggests that respiratory viral infections in early life constitute a major environmental risk factor for the development of childhood asthma. Respiratory viral infections have also been recognized as the most common cause of asthma exacerbation. The advent of molecular diagnostics to detect respiratory viruses has provided new insights into the role of human rhinovirus (HRV) infections in the pathogenesis of asthma. However, it is still unclear whether HRV infections cause asthma or if wheezing with HRV infection is simply a predictor of childhood asthma. Recent clinical and experimental studies have identified plausible pathways by which HRV infection could cause asthma, particularly in a susceptible host, and exacerbate disease. Airway epithelial cells, the primary site of infection and replication of HRV, play a key role in these processes. Details regarding the role of genetic factors, including ORMDL3, are beginning to emerge. This review discusses recent clinical and experimental evidence for the role of HRV infection in the development and exacerbation of childhood asthma and the potential underlying mechanisms that have been proposed.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.24 no.3
• /
• pp.73-84
• /
• 2011

Objectives: This study examined the recent update of factors affect length and regularity of menstrual cycle and symptoms need for diagnosis in oriental medicine. Methods: For factors, we searched the key word "menstrual cycle length and factor" in ScienceDirect(http://www.sciencedirect.com) and we mainly searched symptoms in the journal of oriental obstetrics & gynecology and text. Results: The result are shown in the Table 1-3. Conclusion: In fact as the fluctuation of menstrual cycle length and regularity is very high in healthy women, we must observe the factor affect menstrual cycle with attention even though rule out disease, operation and HRT etc. these researches show potential to compound oriental medicine care and factor of menstrual cycle change.

• ETRI Journal
• /
• v.34 no.4
• /
• pp.629-632
• /
• 2012

This letter investigates the combination of the Chase-2 and sum-product (SP) algorithms for low-density parity-check (LDPC) codes. A simple modification of the tanh rule for check node update is given, which incorporates test error patterns (TEPs) used in the Chase algorithm into SP decoding of LDPC codes. Moreover, a simple yet effective approach is proposed to construct TEPs for dealing with decoding failures with low-weight syndromes. Simulation results show that the proposed algorithm is effective in improving both the waterfall and error floor performance of LDPC codes.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2006.05a
• /
• pp.265-270
• /
• 2006

In an organization where major business operations are geared by business process management system(BPMS), routine tasks are processed according to the predefined business processes. However, most business operations are subject to some sort of exceptions, and the exceptional situations require update of the existing business process model, or a new business process model has to be defined to handle the exceptions. This paper proposes a system architecture that deploys business process repository as the media for storage and retrieval of the various business process models developed for exception handling. Well defined situation variables and decision variables play the key role for efficient storage and retrieval of the business process models developed for exception handling. The data mining technique C5.0 was used to build the optimum path for the process repository search tree.