• Journal of Chest Surgery
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• v.25 no.1
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• pp.1-16
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• 1992

The quantitatively measured local myocardial perfusion rates with microspheres are used as an objective indicator of even distribution of cardioplegic solution, and the efficacy of the retrograde right atrial route of cardioplegia is evaluated in hearts with various levels of coronary arterial obstruction. After initial antegrade cardioplegia under the median sternotomy and aortic cannulation, 60 hearts from anesthetized New Zealand white rabbits are divided in random order as normal group [ligated left main coronary artery ; MA, MR] and diagonal group [ligated proximal diagonal artery ; LA, LR]. Half of each group [N=10] are perfused with antegrade cardioplegia[A] under the pressure of 100 cmH2O and the other half with retrograde right atrial route[R] under the pressure of 60 cmH2O[St. Thomas cardioplegic solution mixed with measured amount of microspheres]. The myocardium is subdivided into segments as A[atria], RV[right ventricle]. S[septum], LV[normally perfused left ventricular free wall], ROI[ischemic myocardium of left ventricular free wall]. LV and RQI are further divided into N[subendocardium] and P[subepicardium]. The resulting local myocardial perfusion rates and N /P of each group are compared with Wilcoxon rank sum test. The weight of the hearts is 5.94$\pm$0.66g, and there are no statistically significant dif-ferences[p>0.05, ANOVA] between six compared group. The mean flow rate[F: ml /g / min] of MR group is comparable with MA group[p>0.05], but in N and L group, there are significantly depressed F with right atrial route of cardioplegia, which means elevated perfusion resistance with this route. In spite of no significant differences in delivered doses of microsphere[DEL] between compared groups[p>0.05, ANOVA], there are significantly depressed REC and NF in hearts with right atrial cardioplegia which suggests increased requirement of cardioplegic solution with this route. The interventricular septum shows poor perfusion with right atrial route of cardioplegia without obstruction of supplying coronary arteries. But, with obstruction of coronary artery supplying septum as in M group, the flow rate is superior with right atrial route of infusion. The left ventricular free wall perfusion rates of every RQI with R route are superior to that of A route[p<0.05]. But, in LV segments, there are unfavorable effects of right atrial cardioplegia in L group, although the subendocardial perfusion is well maintained in N group. The LV free wall of left main group shows depressed perfusion rates with antegrade route as compared with RQI segments of diagonal group. But, by contraries, there are increased perfusion rates and superior N /P ratio with retrograde right atrial route. It implies more effective perfusion with right atrial route of cardioplegia in more proximal coronary arterial obstruction[i.e., M group as compared with L group]. As a conclusion, all region of ischemia have superior perfusion rates with right atrial car-dioplegia as compared with antegrade route, and especially excellent results can be obtained in hearts with more proximal obstruction of coronary arteries which would otherwise result in more severe ischemic damage. But, the depressed perfusion rates of the segments with normal coronary artery in hearts with coronary arterial obstruction may be a problem of concern with right atrial cardioplegia and needs solution.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1366-1372
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• 2018

Objective: A disintegrin and metallopeptidase with thrombospondin motifs type 8 (ADAMTS8) is crucial for diverse physiological processes, such as inflammation, tissue morphogenesis, and tumorigenesis. The chicken ADAMTS8 (chADAMTS8) gene was differentially expressed in the kidney following exposure to different calcium concentrations, suggesting a pathological role of this protein in metabolic diseases. We aimed to examine the molecular characteristics of chADAMTS8 and analyze the gene-expression differences in response to toll-like receptor 3 (TLR3) stimulation. Methods: The ADAMTS8 mRNA and amino acid sequences of various species (chicken, duck, cow, mouse, rat, human, chimpanzee, pig, and horse) were retrieved from the Ensembl database and subjected to bioinformatics analyses. Reverse-transcription polymerase chain reaction (RT-PCR) and quantitative PCR (qPCR) experiments were performed with various chicken tissues and the chicken fibroblast DF-1 cell line, which was stimulated with polyinosinic-polycytidylic acid (poly[I:C]; a TLR3 ligand). Results: The chADAMTS8 gene was predicted to contain three thrombospondin type 1 (TSP1) domains, whose amino acid sequences shared homology among the different species, whereas sequences outside the TSP1 domains (especially the amino-terminal region) were very dif­ferent. Phylogenetic analysis revealed that chADAMTS8 is evolutionarily clustered in the same clade with that of the duck. chADAMTS8 mRNA was broadly expressed in chicken tissues, and the expression was significantly up-regulated in the DF-1 cells in response to poly(I:C) stimulation (p<0.05). These results showed that chADAMTS8 may be a target gene for TLR3 signaling. Conclusion: In this report, the genetic information of chADAMTS8 gene, its expression in chicken tissues, and chicken DF-1 cells under the stimulation of TLR3 were shown. The result suggests that chADAMTS8 expression may be induced by viral infection and correlated with TLR3-mediated signaling pathway. Further study of the function of chADAMTS8 during TLR3-dependent inflammation (which represents RNA viral infection) is needed and it will also be important to examine the molecular mechanisms during different regulation, depending on innate immune receptor activation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.961-967
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• 2019

This research presents an efficient method based on computational fluid dynamics (CFD) for estimating the resistance performance of a ship with a large settlement amount and a dynamic trim. The settlement of the inviscid flow analysis and the results of dynamic trim were used to set a large attitude for the ship prior to performing a viscous flow analysis; a viscous flow analysis was subsequently performed by Dynamic Fluid Body Interaction (DFBI). This method is termed as method I, in which a simple grating system can be used without employing the overset mesh technique by setting many attitudes before interpretation. Thus, method I is advantageous in reducing calculation time and improving calculation accuracy. The viscous flow analysis was performed using a commercial CFD code STAR-CCM+. Compared with the final convergence result, the first viscous flow analysis result of method I exhibited a variation of less than 1 % of resistance. The result was obtained by changing the gratings each time an attitude is changed at each calculation stage, based on the DFBI method provided to STAR-CCM+ using a simple grating system, which is not a superposed grating. This method is termed as method II. Compared with method II of resistance, method I exhibited a dif erence of 0.03-0.6 % for linear velocity. The results of method I were confirmed to be qualitatively and quantitatively appropriate through comparison with several trillion simulations.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.255-258
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• 2000

본 연구는 육성돈에 있어 인분해효소인 phytase의 첨가가 환경친화성사료개발을 위한 기초자료로 사용하기 위해 영양소 이용률을 측정하였다. 대조구는 옥수수-대두박의 육성돈 사료이고, 처리구는 대조구 사료에 Phytase의 첨가 수준을 500 unit 및 1,000 unit을 첨가한 구로 3×3 Latin Square 방법으로 실시하였다. 건물과 질소에 대한 소화율에서는 각 처리구간에 유의적인 차이가 없었다(P>0.05). 회분, 칼슘 및 인의 소화율의 경우 phytase 첨가구가 대조구에 비해 높은 수준을 보였다(P<0.05). 돼지가 섭취한 인의 양은 phytase 첨가구가 대조구에 비해 증가하였다. 또한 인의 흡수량에서 phytase 첨가구가 대조구에 비해 높았다(P<0.05) 분과 뇨의 총 인 배설량은 유의적인 차이를 나타내지 않았다. 칼슘의 섭취량은 처리구가 대조구에 비해 높았다. 칼슘의 분 배설량은 각 처리구간에 별 다른 차이를 보이지 않았으나(P>0.05), 뇨의 배설량은 처리구가 대조구보다 적은 양이 배설되었다. 소화된 아미노산 중 cystine, isoleucine, tyrosine, phenylalanine은 처리구가 대조구에 비해 소화율이 현저히 증가된 것을 알 수 있었다(P<0.05). Asparagine, threonine, serine, methionine, leucine의 경우 phytase를 500 unit 첨가한 구가 높은 소화율을 나타내었다(P<0.05). 한편 lysine, histidine, arginine 등의 다른 아미노산은 처리구가 대조구보다 약간의 소화율 증가를 보였으나 통계적 유의차는 나타나지 않았다(P>0.05). 결론적으로 인분해효소 phytase를 사료내 첨가하므로서 분중 영양소를 줄일 수 있는 환경친화성 사료를 개발 가능하다고 사료된다. 체결홈이 형성된 체결부를 갖는 안경집과 이것에 결합되는 체결구가 마련되어 개폐되는 커버가 형성된 케이스로 구성된다.로 금형설계 및 제작기간을 단축하고자 한다.ere demonstrated in rats after i.c.v., intraperitoneally and orally administration, respectively. The antiepileptical effects by the combination of compounds from ginseng; were compared with the iuluence of Rg1, Rb1, Rc and with the well known antiepileptical drugs such as carbamazepine, valproic acid. The base for the research is obtained by using the WAG/Rij strain (Luijtelaar, Coenen, Kuznetcova), an excellent genetic model for human generalized absence epilepsy. The improving action of gensinosides was effectively demonstrated on the model of electrical kindling of amygdala of WAG/Rij rats with genetically determined absences, and the influences of ginsenosides on the slow wave discharges have also been being investigated. The different characteristics of a kindling process exerted in the sex-dif

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.9
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• pp.211-216
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• 2016

Worldwide casualties caused by earthquakes, floods, fire or other disaster has been increasing. So many researchers are being actively done technical studies to ensure golden-time. In this paper if a disaster occurs, use the IoT technologies in order to secure golden-time and transmits the message after to find the user of the accident area first. When the previous job is finished, gradually finds a user of the surrounding area and transmits the message. For national emergency information, OPEN API of Korea Meteorological Administration was used. To collect detailed information on a relevant area in real time, this study established the system that connects and integrates Crowd Sensing technology with BLE (Bluetooth Low Energy) Beacon technology. Up to now, the CBS based on base station has been applied. However, this study designed and mapped DB in the integration of Beacon based user positioning and national administrative address system in order to estimate local users. In this experiment, the accuracy and speed of information dif6fusion algorithm were measured with a rise in the number of users. The experiments were conducted in a manner that increases the number of users by one thousand and was measured the accuracy and speed of the message spread transfer algorithm. Finally, became operational in less than one second in 20,000 users, it was confirmed that the notification message is sent.

• Explosives and Blasting
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• v.39 no.1
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• pp.10-21
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• 2021

Brittle materials such as rocks and concretes exhibit large strain-rate dependency under dynamic loading conditions. This means that the mechanical properties of such materials can significantly be varied according to load velocity. Thus, the strain-rate dependency is recognized as one of the most important considerations in solving problems of blast engineering or rock dynamics. Unfortunately, however, studies for characterizing the dynamic properties of domestic rocks and other brittle materials are still insufficient in the country. In this study, dynamic tensile tests were conducted using the Hopkinson pressure bar apparatus to characterize the dynamic properties of Geochang granite and high-strength concrete specimens. The dynamic Brazilian disc test, which is suggested by ISRM, and the spalling method were applied. In general, the latter is believed to have some advantages in experiments under high-strain rate deformation. It was found from the tests that there were no significant difference between the dynamic tensile strengths obtained from the two different test methods for the two materials given. However, this was not the expected result before the tests. Actually, authors expected that there be some differences between them. Hence, it is thought that further investigations are needed to clarify this results.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1044-1053
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• 2022

Time domain reflectometry (TDR) is a diagnostic technique to evaluate the physical integrity of cable and finds application in leak detection and localization of piping system. In this study, a cable-shaped leak detection sensor was proposed using the TDR technique for monitoring leakage detection of ship's engine room seawater piping system. The cable sensor was developed using a twisted pair arrangement and wound by an absorbent material. The availability and performance of the sensor for leak detection and localization were evaluated on a lab-scale pipeline set up. The developed sensor was installed onto the pipes and flanges of the lab-scale set up and various TDR waveforms were acquired and analyzed according to the dif erent variables including the number of twists and sheath thickness. The result indicated that the twisted cable sensor was able to produce clear and smooth signal as compared to the TDR sensor with a parallel arrangement. The optimal number of twist was determined to be above 10 per the unit length. The optimal diameter of sheath thickness that results in the desired sensitivity was determined to be ranging from 80% up to 120% of the diameter of the conductor. The linear regression analysis for estimation of leak localization was carried out to estimate the location of the leakage, and the result was a determination coefficient of 0.9998, indicating a positive relationship with the actual leakage point. The proposed TDR based leak detection method appears to be an effective method for monitoring leakage of ship's seawater piping system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.219-227
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• 2021

This study aimed to determine the importance of the policies formulated through the Ministry of Maritime Affairs and Fisheries' master plan for Seafarer's policy. To confirm the importance of the Seafarer's policy, AHP analysis was conducted on the 3 main policies and 15 auxiliary policies established by the master plan for Seafarer's policy. To analyze the reliability of the survey, we investigated the inconsistency ratio of 34 respondents retrieved. We found that 25 respondents validated the reliability of the findings. The analysis showed that the policy of establishing a stable supply and demand system was the most important among the main policies for seafarers, while the policy of fostering seafarers linked to jobs was the most important one among the auxiliary policies. By group, the government recognized establishing a stable supply and demand system as a priority of policy. Dif erences were found on the fact that improving working conditions and expanding welfare were important for seafarers. This study, which analyzed the importance of the Seafarer's policy through AHP analysis, has the following implications. We established guidelines to enhance efficiency, such as budget allocation by policy according to the importance in implementing Seafarer's policies. Furthermore, our study can be used as basic data for establishing a master plan for Seafarer's policy by comparing differences in importance per group.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1106-1115
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• 2021

In this study, a fin that controls ship stern flow was attached on stern hull of a 80k bulk carrier to improve resistance performance. The rectangular cross-sectional fin was attached at several locations on the hull, and angle to streamline was changed with constant length, breadth, and thickness. The resistance performance and wake on propeller plane of the hull with and without the fin were analyzed using model-scale computational fluid dynamics simulation. The analysis results were extrapolated to full-scale to compare the performance and wake of the full-scale ship. First, the fin changed path of bilge vortex that flowed into the propeller along the stern hull without the fin to transom stern. This change increased pressure of the stern hull and upper region of the propeller, so pressure resistance and total resistance of the hull were reduced - the nearer the fin location to after perpendicular (AP) and base line of the hull, the larger the reduction of the resistances. Second, nominal wake fraction of the hull with the fin was lower than that without the fin. This dif erence was in proportion to the angle of the fin, but the total resistance reduction was in proportion until a certain angle at which the reduction was maximum. The largest total resistance reduction was approximately 2.1% at 12.5% of length between perpendiculars from the AP, 10% of draft from the base line, and 14° with respect to the streamline.

• 한국노년학
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• v.40 no.1
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• pp.73-89
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• 2020

This study validates an abridged version of the age integration scale by Chung et al. (2015), which constitutes sub-dimensions of age flexibility and age heterogeneity-from Riley et al. (1994)-and observes disparities in the perception of age integration among different socio-cultural characteristics. This study analyzed 1,433 people in the "Age Integration and Generation Integration Survey" data, with the support of the Social Science Competency Enhancement Project (SSK) (supported by the Korea Research Foundation). This paper analyzed the data using exploratory factor analysis, confirmatory factor analysis, multiple-group factor analysis, and a compare means test. The results are as follows. First, the scale was abridged to 13 items from 28, of which eight items concern age heterogeneity and five concern age flexibility. Second, the multi-group analysis did not show a significant difference among younger, middle, and older age groups, therefore allowing the scale to be used among all age groups. Third, when sociocultural characteristics were observed, younger adults showed differences in their levels of age integration, age heterogeneity, and age flexibility regarding their residential area. Middle-aged adults showed dif f erences in their levels of age integration, age heterogeneity, and age flexibility regarding their residential area and social status. Older adults showed differences in their level of age integration regarding their residential area, education level, and social status. They also showed differences in the level of age flexibility regarding their residential area and social status and differences in the level of age heterogeneity regarding their residential area and education. Based on the results of the study, political and practical measures to promote perception on age integration in the future were suggested.