• The Journal of Society for e-Business Studies
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• v.7 no.1
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• pp.66-74
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• 2002

Through the increment of requirement for EC(Electronic Commerce) oriented communication services, security multicast communications is becoming more important. However, multicast to EC environment is much different from unicast concept most network security protocols. On the network security, using mandatory access control of multilevel architecture which assigns a specific meaning to each subject, so we accomplish access control. In this way, access control security based on the information security level is proposed. A security protocol based on the architecture proposed in this paper would be utilized in security multicast communications, group key management service and leveled security service through multilevel EC security policy, Also we discuss and propose the security level scaleability and key management method on the network.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1186-1192
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• 2012

In Jeju Smart Grid field test, Zigbee technology is being used as one of customer side solutions for AMI. Although Zigbee networks that provides effective connectivity and control among devices are advantages in ease of implementation and use, the data can be exposed to cyber attacks such as eavesdrop, unauthorized data dissemination and forgery. Currently authentication and confidentiality services are provided with the network and link keys generated based on public key pairs that are pre-installed in offline. However, the network is vulnerable once a hacker intrudes into a local network because operation and management policies for the generated keys are not well-established yet. In this paper, the vulnerability of the Zigbee security system in the customer side environment of Jeju Smart Grid field test is analyzed. Then, two-way authentication with the unique identifiers of devices and user-specific group management policies are proposed to resolve the vulnerability.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.513-524
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• 2009

Urban land consolidation, which is to reform land parcels to remove fragmentation and produce ideal blocks, is an effective means for urban renewal. Successful urban land consolidation brings out great benefits to the city officials as well as general public, such as improved city image, increased land value, and more effective land use. However, urban land consolidation can be detrimental to environment, especially in the ecological aspects, while the execution of land consolidation has been focused solely on development for the sake of human benefits. To remove negative effects of urban land consolidation to the ecological system, this paper is intended to establish a set of criteria for evaluating ecological impacts of an urban land consolidation plan. Firstly, key ecological indicators are identified using a special group decision-making process called "habitual domain analysis" and then individual weighting of each indicator is recorded by analytical hierarchy process. An urban ecological evaluation model with 4 levels and 23 indicators is thus developed.

• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.246-262
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• 2007

The performance of projects has always been an area of interest in the construction industry. Roles of all construction supply chain partners are necessary; however the role of a contractor firm in the construction project is pivotal. So, this research intended to explore a Construction Firm's performance criteria which could measure the level of performance of that firm in an ongoing project. Data was collected from construction professionals working in three principal project participant organizations, namely Owner, Consultant and Contractor. A total of 113 nos. of performance measuring items were sorted from literature review and used to collect data. Statistical tools processed by SPSS program was employed to analyze the data. Out of total 113 items, only 65 nos. of variables were found to be acceptable to every population group of this study. Factor analysis revealed 12 key performance predicting factors (KPPF) with 53 predictive indicators. 12 KPPFS with index weight are: work progress and smoothening (9.3%), change order management and work accuracy (9.1%), business relationship building (8.1%), adequacy of construction work procedure (8.6%), quality performance (8.0%), health and site safety adequacy (8.8%), Innovative contractor (8.0%), adequacy of construction site information (6.8%), compliance with contract plan/specification requirements (8.9%), creditworthiness and financial capability (8.3%), intra-agency relationship and responsiveness (7.0%) and resource management (9.2%). These results could be useful to project management body to evaluate performance of its contractor firm on site as well as the contractor itself to assess own performance and its subcontractors on-site.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.61-70
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• 2005

We propose and implement a flexible secure peer-to-peer(P2P) file sharing scheme which can be used for data sharing among closed user group (CUG) members. When a member wants to share data, notification messages are sent to the members with whom the member wants to share data. Each notification message includes one-time password encrypted with the receiver's public key. A member who received the notification message can download the data by using the one-time password. The proposed scheme provides selective sharing, download confirmation and efficient storage management. In terms of security, the proposed scheme supports authentication, entity privacy, replay attack protection and disguise prevention. We also implement the proposed system and find that the system is very useful among P2P service of closed user groups.

• Animal Bioscience
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• v.35 no.2
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• pp.224-235
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• 2022

Objective: Cage rearing has critical implications for the laying duck industry because it is convenient for feeding and management. However, caging stress is a type of chronic stress that induces maladaptation. Environmental stress responses have been extensively studied, but no detailed information is available about the comprehensive changes in plasma metabolites at different stages of caging stress in ducks. We designed this experiment to analyze the effects of caging stress on performance parameters and oxidative stress indexes in ducks. Methods: Liquid chromatography tandem mass spectrometry (LC/MS-MS) was used to determine the changes in metabolites in duck plasma at 5 (CR5), 10 (CR10), and 15 (CR15) days after cage rearing and traditional breeding (TB). The associated pathways of differentially altered metabolites were analyzed using Kyoto encyclopedia of genes and genomes (KEGG) database. Results: The results of this study indicate that caging stress decreased performance parameters, and the plasma total superoxide dismutase levels were increased in the CR10 group compared with the other groups. In addition, 1,431 metabolites were detected. Compared with the TB group, 134, 381, and 190 differentially produced metabolites were identified in the CR5, CR10, and CR15 groups, respectively. The results of principal component analysis (PCA) show that the selected components sufficiently distinguish the TB group and CR10 group. KEGG analysis results revealed that the differentially altered metabolites in duck plasma from the CR5 and TB groups were mainly associated with ovarian steroidogenesis, biosynthesis of unsaturated fatty acids, and phenylalanine metabolism. Conclusion: In this study, the production performance, blood indexes, number of metabolites and PCA were compared to determine effect of the caging stress stage on ducks. We inferred from the experimental results that caging-stressed ducks were in the sensitive phase in the first 5 days after caging, caging for approximately 10 days was an important transition phase, and then the duck continually adapted.

• Archives of Plastic Surgery
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• v.39 no.4
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• pp.376-383
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• 2012

Background No consensus has been reached regarding the outcome of management of local recurrence after transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction. This study demonstrated the presentation, management, and outcomes of local recurrence after immediate TRAM breast reconstruction. Methods A comparison was conducted among 1,000 consecutive patients who underwent immediate breast reconstruction with a pedicled TRAM flap (TRAM group) and 3,183 consecutive patients who underwent only modified radical mastectomy without reconstruction (MRM group) from January 2001 to December 2009. The presentation, treatment, and outcome including aesthetics and overall survival rate were analyzed. Results Local recurrences occurred in 18 (1.8%) patients (TRAM-LR group) who underwent TRAM breast reconstruction and 38 (1.2%) patients (MRM-LR group) who underwent MRM only (P=0.1712). Wide excision was indicated in almost all the local recurrence cases. Skin graft was required in 4 patients in the MRM-LR group, whereas only one patient required a skin graft to preserve the mound shape in the TRAM-LR group. The breast mound was maintained in all 17 patients that survived in the TRAM-LR group even after wide excision. The overall survival rate was 94.4% in the TRAM-LR group and 65.8% in the MRM-LR group (P=0.276). Conclusions Local recurrence after immediate TRAM flap breast reconstruction could be detected without delay and managed effectively by multiple modalities without reducing overall survival rates. Breast mound reconstruction with soft autologous tissue allowed for primary closure in most of the cases. In all of the patients who survived, the contour of their reconstructed breast remained.

• Journal of Chest Surgery
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• v.49 no.6
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• pp.427-434
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• 2016

Background: Recent studies have demonstrated the benefits of off-pump coronary bypass grafting over the on-pump technique in patients with chronic kidney disease (CKD). To further reduce the risk of acute kidney injury and the need for renal replacement therapy, even in patients undergoing off-pump coronary artery bypass grafting, we adopted protocol-based perioperative management for patients with CKD. Methods: From December 2012 to March 2015, 265 patients underwent isolated off-pump coronary artery bypass grafting. To analyze renal function in a stable condition, we excluded 12 dialysis-dependent end stage renal failure and 10 emergency or urgent cases. Among the remaining 243 patients, 208 patients had normal kidney function (normal group), and 35 patients had CKD (CKD group). Minimizing contrast exposure, ensuring adequate hydration, using strict drug dosage adjustment, and optimizing hemodynamic status were key elements of the protocol for the CKD group. Results: The risk of acute kidney injury was about ${\times}3$ higher in the CKD group than in the normal group (p=0.01). Estimated glomerular filtration rates and serum creatinine levels deteriorated until the third postoperative day in the CKD group. However, by adopting protocol-based perioperative management, this transient renal dysfunction recovered to preoperative levels by the fifth postoperative day without requiring renal replacement therapy in all cases. Conclusion: Off-pump coronary bypass surgery combined with this protocol-based perioperative management strategy in patients with non-dialysis-dependent CKD could mostly be performed without renal replacement therapy.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.3
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• pp.21-37
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• 2001

Riding on the wave of the information technology revolution, a slow of internet venture businesses (IVB) came into being. Hence, one of the recent developments in Korean capital market has been the proliferation of IVB, which is in accordance with the worldwide trend of ‘new economy’. Although the fair valuation is crucial for the nourishment of IVB, it is difficult to apply traditional valuation methods to these firms without reservation. It is due to the facts that most venture firms have little records of performance, grow unprecedently fast, and have highly uncertain future. The main purpose of this study is to suggest performance evaluation system of IVB and to develop KPE (Key Performance Indicators). Our empirical study is based upon Kaplan & Norton’s Balance Scorecard (BSC) approach. Specifically, our research has been conducted by the following two subsequent procedures: Firstly, seven internet venture firms have been selected and their executives have been interviewed by FGI(Focus Group Interview) method. Based upon these results, performance indicators have been developed. Secondly, by using the above mentioned BSC items (i.e., financial perspective, customer perspective, internal perspective and innovation & learning perspective), questionnaires have been constructed and sent to IVB through e-mail as well as over the Fax. Among the collected 110 samples, reliable 106 samples have been used to build BSC model and to draw our conclusion. In the future study, it would be much better to consider the role of strategy in IVB and the causal relationship among Key Performance Indicators of BSC.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.2
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• pp.32-45
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• 2023

Implementing Severe Accident Management (SAM) strategies is crucial for enhancing a nuclear power plant's resilience and safety against severe accidents conditions represented in the analysis of Station Blackout (SBO) event. Among these critical approaches, the In-Vessel Retention (IVR) through External Reactor Vessel Cooling (IVR-ERVC) strategy plays a key role in preventing vessel failure. This work is designed to evaluate the efficacy of the IVR strategy for a high-power density reactor APR1400. The APR1400's plant is represented and simulated under steady-state and transient conditions for a station blackout (SBO) accident scenario using the computer code, ASYST. The APR1400's thermal-hydraulic response is analyzed to assess its performance as it progresses toward a severe accident scenario during an extended SBO. The effectiveness of emergency operating procedures (EOPs) and severe accident management guidelines (SAMGs) are systematically examined to assess their ability to mitigate the accident. A group of associated key phenomena selected based on Phenomenon Identification and Ranking Tables (PIRT) and uncertain parameters are identified accordingly and then propagated within DAKOTA Uncertainty Quantification (UQ) framework until a statistically representative sample is obtained and hence determine the uncertainty bands of key system parameters. The Systems Engineering methodology is applied to direct the progression of work, ensuring systematic and efficient execution.