• Journal of Chest Surgery
• /
• v.26 no.1
• /
• pp.24-31
• /
• 1993

The long term clinical results following valve replacement with Hancock and Carpentier-Edwards bioprostheses were compared between tow valve models and between tow groups totaling 249 patients who were discharged after valve replacement from 1976 to 1986. The two groups of patients were treated with nonrandomized fashion. Follow-up was 87% complete. Cummulative duration of follow-up was 1909 patient-years, with maximum follow-up duration of 15 years. The actuarial survival for 122 patients with Hancock valves was 95.2%[\ulcornerstandard deviation] and 84.4% after 5 and 10 years of follow-up, respectively. Comparable figures for 127 patients undergoing valve replacement with Carpentier-Edwards valves were 87.3% and 76.4%, respectively[p=NS]. The probability of freedom from structural valve deterioration after 5 and 10 years of follow-up was 97.2% and 60.6%, respectively, with Hancock valves and 97.2% and 55.7%, respectively, with Carpentier-Edwards valves[p=NS]. Considering all 249 patients, multivariate [Cox model] regression revealed that ejection fraction was only significant predictor of structural valve deterioration. The probability of freedom from thromboembolism after 5 and 10 years of follow-up was 91.3% and 86.4%, respectively, with Hancock valves and 94.2% and 82.5%, respectively, with Carpentier-Edwards valves[p=NS]. Hence more strict control of anticoagulation should be done on patients with left atrial factors. In summary, there were no significant differences in actuarial survival rate and major valve related complications between tow valve models. These results suggests that its use should be confined to older patients or patients with a contraindication of anticoagulation.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.44 no.2 s.314
• /
• pp.19-24
• /
• 2007

In this paper, we deal with suggestion of energy efficient MAC protocol. The scheme(I-MAC) makes the active duty-cycle duration based on by utilizing data frequency. Data frequency is made by checking a check bit of Link layer. By being studies on NS-2 simulation environments, the proposed scheme was proved to be improved in terms of energy efficiency of 50 % and to be similar to throughput of S-MAC on every time interval.

• Journal of Korean Society of Water and Wastewater
• /
• v.20 no.6
• /
• pp.867-874
• /
• 2006

The goal of this study is to assess cast iron pipes (CIPs) and present a residual tensile strength prediction model using pit characteristics and fracture toughness. The results is the followings. First, average pit depths of collected CIPs were in the range from 0.63 to 6.49 mm, loss of tensile strength compared with net metallic tensile strength were from -7.06 to 67.91 percent. Second, fracture toughness for NS-CR-1, NS-CR-2, and NS(2)-CR-1 were in the range from 62.85 to $89.39kgf/mm^2{\sqrt{mm}}$, and average of those samples was $73.69kgf/mm^2{\sqrt{mm}}$ on CIPs. Third, the models developed in this study by using pit characteristics and fracture toughness showed a little good correlation for measured residual tensile strength, and the results will be expected to help for water utilities to manage CIPs in the aspect of rehabilitation and assessment of structural safety on CIPs.

• International Journal of Computer Science & Network Security
• /
• v.22 no.7
• /
• pp.13-20
• /
• 2022

Basically Mobile Ad Hoc Network (MANET) is an autonomous system with the collection of mobile nodes, these nodes are connected to each other by using wireless networks. A mobile ad hoc network poses this quality which makes topology in dynamic manner. As this type of network is Ad Hoc in nature hence it doesn't have fixed infrastructure. If a node wishes to transfer data from source node to a sink node in the network, the data must be passed through intermediate nodes to reach the destination node, hence in this process data packet loss occurs in various MANET protocols. This research study gives a comparison of various Mobile Ad Hoc Network routing protocols like proactive (DSDV) and reactive (AODV, DSR) by using random topology with more intermediate nodes using CBR traffic. Our simulation used 50, 100, and 150 nodes variations to examine the performance of the MANET routing protocols. We compared the performance of DSDV, AODV and DSR, MANET routing protocols with the result of existing protocol using NS-2 environment, on the basis of different performance parameters like Packet Delivery Ratio, average throughput and average end to end delay. Finally we found that our results are better in terms of throughput and packet delivery ratio along with low data loss.

• Korean Journal of Biological Psychiatry
• /
• v.19 no.2
• /
• pp.71-76
• /
• 2012

Objectives : Novelty seeking (NS) represents a dopaminergically modulated tendency toward frequent exploratory activity. Considering the reports showing the relationship between exploratory activity and amygdalar function and structure, and the fact that amygdala is one of the key structures that constitute the dopaminergic pathway in the brain, amygdala might be closely related to NS tendencies. Amygdalar subregional analysis method, which has the enhanced sensitivity compared to the volumteric approach would be appropriate in investigating the subtle differences of amygdalar structures among healthy individuals. The aim of the current study was to examine whether amygdalar subregional morphometric characteristics are associated with the NS tendencies in healthy adults using the amygdalar subregional analysis method. Methods : Twenty-six healthy adults (12 males, 14 females ; mean age $29.8{\pm}6.2$ years) were screened for eligibility. All subjects completed the Korean version of the Temperament and Character Inventory (TCI) and underwent high-resolution brain magnetic resonance imaging. Individuals were divided into 2 groups according to NS scores of the TCI. Results : Individuals of the high NS group had significantly larger laterobasal subregions in right amygdala, after adjustment with the brain parenchymal volumes. Sensitivity analyses for each potential confounding factor such as age, education years and Hamilton Depression Rating Scale (HDRS) scores demonstrated consistent results. Conclusions : This study suggests that NS differences are associated with the laterobasal subregion of the amygdala.

• Proceedings of the KIEE Conference
• /
• 2003.10a
• /
• pp.261-263
• /
• 2003

This paper represents the development of national standard(NS) for switching impulse(SI) voltage measuring system rated 500 kV. A traceability of the NS to the international standard could be achieved by the intercomparison test with CSIRO of Australia. According to the IEC 60060-2, a measurement uncertainty was assessed. As a result of the tests, a measurement uncertainty and step response characteristics were satisfied with the requisite for NS.

• Journal of Life Science
• /
• v.13 no.5
• /
• pp.576-581
• /
• 2003

Recombinant Arabidopsis non-specific lipid transfer proteins (nsLTPs) was purified from yeast. In order to determine the effect of nsLTPs for an production of anthocyanin in perilla leaves, ‘Manchudlggae’ cultivar was grown at pots that had been applied with different concentration of nsLTPs. The anthocyanin content in AtnsLTP treated leaves increased above two-fold higher than that in control. Also chlorophyll content was increased 16%. It was presumed that AtnsLTPs could be applied to increase high quality of perilla leaves.

• Journal of Powder Materials
• /
• v.7 no.2
• /
• pp.93-101
• /
• 2000

In order to clarify the enhanced sintering behavior of nanostructured(NS) W-Cu powder prepared by mechaincal alloying, the sintering behavior during heating stage was analysed by a dilatometry with various heating rates. The sintering of NS W-Cu powders was characterized by the densification of two stages, having two peaks in shrinkage rate curves. The temperature at which the first peak appear was much lower than Cu melting point, and dependent on heating rate. On the basis of the shrinkage rate curves and the microstructural observation, the coupling effect of nanocrystalline W-grain growth and the liquid-like behavior of Cu phase was suggested as a possible mechanism for the enhanced sintering of NS W-Cu powder in the state.

• Proceedings of the KIEE Conference
• /
• 1988.07a
• /
• pp.311-314
• /
• 1988

This paper describes 256k (256K ${\times}$1) CMOS SRAM utilizing 1.2um double-polysilicon and double-metal CMOS process. A typical access time of 16ns with a 30-pF load has been achieved through the use of a block architecture, a new decoder, an unique bit-line scheme and an optimized process. Operating current is 55mA at 40MHz and 15mA at 10MHz. A high-resistive polysilicon load has been used to achieve a standby current of 3uA.

• Journal of Microbiology
• /
• v.33 no.3
• /
• pp.260-266
• /
• 1995

Hepatitis C virus (HCV) has been considered as a mojor causative agent of post-transfusion related non-A, non-B hepatitis. In this study, the cDNA sequence of NS4 region of HCV (HCV-S) obtained from a Korean patient's plasms was determined. Comparative nucleotide sequence analysis between to type II. 67.2% homology to type III, and 66.4% homology to type IV. The putative amino acid sequence homologies to types I, II, III, and IV were 82.8-84.7%, 92.5-95.1%. 72.5, and 71.1%, respectively. This data strongly suggests that HCV-S should be classified as type II. Significant similarities of hydrophobicity profiles and putative transmembranous domains were found in HCV-S and four major prototypes, indicating that the protein structure is similar in spite of the heterogeneities of intertype homologies at the level of the psrimary nucleotide and amino acid sequences.