• The KIPS Transactions:PartC
• /
• v.11C no.4
• /
• pp.439-446
• /
• 2004

In the Internet, user authentication is the most important service in secure communications. Although password-based mechanism is the most widely used method of the user authentication in the network, people are used to choose easy-to-remember passwords, and thus suffers from some Innate weaknesses. Therefore, using a memorable password it vulnerable to the dictionary attacks. The techniques used to prevent dictionary attacks bring about a heavy computational workload. In this paper, we describe a recent solution, the Optimal Strong-Password Authentication (OSPA) protocol, and that it is vulnerable to the stolen-verifier attack and an impersonation attack. Then, we propose an Improved Optimal Strong-Password Authentication (I-OSPA) protocol, which is secure against stolen-verifier attack and impersonation attack. Also, since the cryptographic operations are computed by the processor in the smart card, the proposed I-OSPA needs relatively low computational workload and communicational workload for user.

• Journal of Environmental Health Sciences
• /
• v.38 no.3
• /
• pp.213-222
• /
• 2012

Objectives: This study was undertaken in order to evaluate by work space zoning and structure the concentrations of biological contaminants in the indoor air of domestic office buildings. Methods: Air samples were collected in the office spaces of 15 office buildings in Seoul from June 28 to July 28, 2011. Prior to the sampling, each office was classified into 'open-plan office', 'cellular office' and 'mixed office' according to the work space zoning. To evaluate the biological contamination of indoor air, total suspended bacteria (TSB), Gram positive bacteria (GPB), Staphylococcus aureus (S.A), Methicillin-resistant Staphylococcus aureus (MRSA), Gram negative bacteria (GNB) and fungi were investigated. During the sampling, temperature, relative humidity and carbon dioxide ($CO_2$) were measured. Results: The TSB concentrations ($GM{\pm}GSD$) were $452({\pm}1.3)cfu/m^3$ in open-plan offices, $366({\pm}1.3)cfu/m^3$ in cellular offices and $287({\pm}1.5)cfu/m^3$ in mixed offices, and there were significant differences between the three groups (p<0.05). The highest concentrations ($GM{\pm}GSD$) of fungi were found in the indoor air of cellular offices $128({\pm}1.0)cfu/m^3$, which was at least three times higher than the concentrations in mixed offices $43({\pm}1.0)cfu/m^3$ (p<0.05). Conclusions: Microbiological contamination in the indoor air of office buildings by work space structure was the highest with the open-plan office layout which includes no high walls or doors separating the occupants.

• Tuberculosis and Respiratory Diseases
• /
• v.57 no.4
• /
• pp.377-380
• /
• 2004

We report a rare case of idiopathic chylothorax and chyluria. A 31 year-old woman was referred to our hospital with a right-sided pleural effusion. Cream-colored pleural fluid and urine were confirmed as chylothorax and chyluria, respectively, by a lipoprotein electrophoresis. Even though she had previously underwent surgery for pelvic fibrosarcoma and experienced its recurrence, there has been no change of mass size and no evidence of thoracic duct or urinary tract obstruction as of the moment. Hence, idiopathic chylothorax and chyluira was diagnosed. Because she responded poorly to conservative treatment, thoracic duct ligation and pleurodesis were performend ; wherease chyluria was resolved spontaneously.

• Archives of Craniofacial Surgery
• /
• v.10 no.2
• /
• pp.120-126
• /
• 2009

Purpose: Autogenous cartilage is generally first choice in rhinoplasty because of its biocompatibility and resistance to infection. On the other hand, allogeneous cartilage graft might preferred over an autogenous graft to avoid additional donor site scars, morbidity and lengthened operating time. Allogenous costal cartilage ($Tutoplast^{(R)}$) not only have the advantage of averting donor site morbidity but also are resistant to infection, resembling autogenous cartilage graft. We report here a technique for rhinoplasty by using allogenous costal cartilage graft. Methods: Through open rhinoplastic approach, alar cartilage is released from upper lateral cartilage and relocated caudally. After relocation of alar cartilage, allogenous costal cartilage is immobilized by nonabsorbable suture material at caudal aspect of septal cartilage. Caudal end of allogenous costal cartilage is sutured between medial crura of alar cartilage. Tip projection is improved by using interdormal suture, transdormal suture and shield-shape cartilage graft which is harvested from concha Results: No significant resorption and infection was detected in any of patients. Aesthetic and functional results were satisfactory. Conclusion: The low incidence of major complication and versatility of allogeneous costal cartilage graft make safe and reliable source of cartilage graft in rhinoplasty.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.24 no.1
• /
• pp.59-74
• /
• 2014

The social network service is a online service letting users express the personality and enhancing the human network. However, these features result in side effects which diffuse personal information and make users access to treacherous information. Therefore, various access control models have been proposed. However, the access control mechanisms which encrypt data are only able to be applied for controlling access from direct node, and the access control mechanisms without data encryption allow service provider to access all the information. Moreover, both mechanisms do not consider dynamic changes in reliability of the users. In this paper, we propose relationship-based dynamic access control model including encryption of sensitive data, which consider the characteristics of SNS and improves the security of SNS.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.10
• /
• pp.4877-4883
• /
• 2012

As a basic research for revitalization of cycling that is emerging as a means of green transportation, this study aims to analyze the impact of neighbourhood environmental factor perceived by the local residents on cycling satisfaction as the concern for energy and environmental issues is increasing. For this, a survey was conducted through a questionnaire to the residents in Sangju-si and the impact of the perceived neighbourhood environmental factor to cycling satisfaction with ordered logit model was analyzed. The result showed that the factors such as quality of bicycle lane, quality of bicycle conveniences, accessibility of major conveniences, safety of cycling and amenity of street made a significant impact on cycling satisfaction. Based on such result, this study suggested the considerations to be made in designing a cycling environment.

• Korean Business Review
• /
• v.23 no.1
• /
• pp.107-128
• /
• 2010

The east coast area of Gangwon province in Korea is famous for natural beauty, many perfect sights and various kinds of tourist attractions. Especially beaches are one of the most attractive and clean tourist attractions in Gangwon province, when compared to the west and south coast of Korea, the natural environment is more prominent. But there are many problems concering the east coast beaches of Gangwon province, such as environmental disruption, collecting fees for offering services, crowdedness, lack of main convenient facilities, decrease of consumption, unseasonably cool temperatures etc. This study examined several problems as to the beach management of Gangwon province that has been suggested over several years. Finally, the author suggested several improvements to solve the problems as mentioned above.

• Journal of Distribution Science
• /
• v.14 no.11
• /
• pp.91-102
• /
• 2016

Purpose - The objectives of this study are as follows. First, it aims to suggest an analysis model that has integrated the relationship between the two factors and export performance and conduct an empirical analysis of the factors. Second, the study seeks to analyze the mediating effect by setting direct channel governance as a specific activity to connect market orientation, a cultural asset, to export performance. Third, through these analyses, the study intends to apply the relationship between market orientation and direct channel governance that the existing studies have failed to observe comprehensively on SMEs in Korea. Based on these analyses, the study expects to expand the discussion of previous researches by analyzing the mediating effect of direct channel governance. Research design, data, and methodology - This study developed a model that has integrated market orientation, direct channel governance, and export performance. It established 7 hypotheses including the mediating effect of direct channel governance. Market orientation was consisted of customer orientation and competitor orientation, and 4 latent variables were measured by 18 questions. LISREL, an analysis tool of structural equation model, was used for hypothesis test and there were 183 sample for analysis. Results - The analysis results showed that customer orientation has a positive influence on direct channel governance, but competitor orientation did not have a statistically significant effect. On the contrary, export performance showed an opposite result. That is, customer orientation did not have any influence but competitor orientation had a significant influence on export performance. It was also confirmed that there was a significant influence in the relationship between channel governance and export performance. According to the analysis of mediating effect, direct channel governance had a full mediating effect between customer orientation and export performance. Conclusions - The study results demonstrated that it is important to build a direct channel governance on the export SMEs in Korea, especially since the direct channel governance complements the influence of customer orientation that does not directly influence export performance among market orientation activities. This implies that Korean export SMEs must strive to build an effective direct channel governance.

• The KIPS Transactions:PartC
• /
• v.17C no.4
• /
• pp.347-360
• /
• 2010

A condition access system (CAS) refers to a hardware-based system that allows only authenticated users to have access to contents. The CAS has many disadvantages found in that in the replacement of multiple service operator (MSO) a set-top box should be also changed and the smart-card often causes malfunction. To deal with the problems, exchangeable CAS (XCAS) was developed in 2009. However, in the XCAS, no method to authenticate a proper set-top box has been put forward. In this paper, we propose a novel program for set-top authentication in the XCAS. Additionally, we offer a format of certificate of authentication, and procedures of issuing the certificate for broadcasting services suitable for the XCAS. The technical method of authentication a set-top box that will be discussed is of high efficiency since in the MSO it requires only two subjects to communicate during the authentication in the MSO.

• The KIPS Transactions:PartC
• /
• v.17C no.4
• /
• pp.361-370
• /
• 2010

OTP(One Time Password) is a user authentication using secure mechanism to authenticate each other in a way to generate a password, an attacker could intercept the password to masquerade as legitimate users is a way to prevent attacks. The OTP can be implemented as H/W or S/W. Token and card type OTP, implemented as H/W, is difficult to popularize because of having problem with deployment and usability. As a way to replace it implemented as S/W on Mobile or PC is introduced. However, S/W products can be target of malicious attacks if S/W products have vulnerability of implementation. In fact, FSA said the OTP implemented on a mobile have vulnerability of implementation. However, the OTP implemented on a PC have no case about analysis of vulnerability. So, in this paper derive security review and vulnerabilities analysis of implemented on a PC.