• Journal of applied mathematics & informatics
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• v.39 no.5_6
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• pp.601-616
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• 2021

Retrial queueing models have been studied extensively in the literature. These have many practical applications, especially in service sectors. However, retrial queueing models have their own limitations. Typically, analyzing such models involve level-dependent quasi-birth-and-death processes, and hence some form of a truncation or an approximate method or simulation approach is needed to study in steady-state. Secondly, in general, the customers are not served on a first-come-first-served basis. The latter is the case when a new arrival may find a free server while prior arrivals are waiting in the retrial orbit due to the servers being busy during their arrivals. In this paper, we take a different approach to the study of multi-server retrial queues in which the signals are generated in such a way to provide a reasonably fair treatment to all the customers seeking service. Further, this approach makes the study to be level-independent quasi-birth-and-death process. This approach is different from any considered in the literature. Using matrix-analytic methods we analyze MAP/M/c-type retrial queueing models along with Poisson signals in steady-state. Illustrative numerical examples including a comparison with previously published retrial queues are presented and they show marked improvements in providing a quality of service to the customers.

• Korean Journal of Heritage: History & Science
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• v.33
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• pp.4-35
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• 2000

The paddling technique is a Kind of secondary treatments in the process of ceramic forming, which appeared in the Chinese Neolithic Age pottery making. In the case of Korean prehistoric pottery making, it was first introduced together with the kiln firing method from Tongpei region(東北地方) of China in Yan(燕) dynasty occupation period. Korean archaeologists have recognized the adoption of the new technologies as a drastic innovation of ceramic production. And most of them have thought that the diffusion of new techniques, accompanied by the migration of the northern ethnic groups, had been immediately followed by the innovative changes in pottery procdution. However, rejecting the arguments from the simple diffusionist viewpoint, I have first tried to describe the innovation processes in the ceramic production systems as a spatio-temporal process. The paddling technique by the cord-wound paddle, which was first introduced among the various paddles, was associated with the new sort of pottery, round pots fired in low temperature of reducing atmosphere condition. The cord-marked round pots first tried by the indigenous potters in the southern part of Korean were characterized by the relatively low leveled techniques in forming and firing, compared to those of north-east China. The techniques of the round pots were hardly improved in the domestic production system until the appearance of the fully-specialized one. The specialized production system of the round pot, which appeared first in the mid-western region of Korea, showed the diversified paddling techniques and made the noticeable improvements in forming and firing processes.

• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.121-126
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• 1972

The pneumonic lungs of 51 pigs, from which the presence of pasteurella organisms was confirmed by bipolar staining, were examined pathologically. The numbers of pigs in each age group were 22 (43.1%) in 3-4 month group, 20 (39.2%) in 1-2 month group, 7 (13.7%) in 5-6 month group, and 2 (4.0%) in group of more than one year. The lungs of 16 pigs which were regarded as pasteurella pneumonia without any other manifestations were studied pathogically. Grossly, the affected lungs showed pulmonary edema, lobular consolidation and interlobular edema. Pigs over 3 months of age frequently showed chronic condition in which the entire lobe was involved as confluent pneumonia. In such pneumonic lungs, infarction and focal necrosis of the lung parenchyma and deposition of fibrinous exudate on the pleura were encountered. Histologically, the alveolar spaces were filled with fibrinous and leukocytic exudates. The interlobular septae showed marked edema and fibrinous exudate. The process of organization was frequently observed in chronic cases.

• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.47-50
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• 1975

Experimental studies were performed to observe the effect of exposure to 100% oxygen in 2 atmospheres on the lung tissue of rats, and to examine the resistant effect of DL-${\alpha}$-tocopherol. The following results were made through this experiment: 1. Half-lethal time by oxygen poisoning was longer in tocopherol treated group than not treated group. 2. Ratio of lung weight to body weight was significantly higher in fatal group within half-lethal time than survival group (p<0.01). 3. Histopathological changes of the lung by oxygen toxicity were vascular congestion, pulmonary edema, hemorrhage and emphysematous change. The degree of changes were rather marked in experimental group than tocopherol untreated group. Those were regard as the changes being occurred during tolerance process by prolonging half-lethal time.

• Annals of Clinical Neurophysiology
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• v.13 no.1
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• pp.21-25
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• 2011

Periodic lateralized epileptiform discharges (PLEDs) had been debated whether it is ictal or non-ictal phenomenon. As most of PLEDs occur in patients with acute structural lesions, some epileptologists prefer PLEDS as a non-ictal phenomenon, rather an obscure epiphenomenon of etiological diseases. But, almost half of the patients with PLEDs do not have acute structural lesions in the brain and metabolic disorders or old CNS lesions may cause PLEDs and even more, no brain lesion was identified in some patients. There are many data supporting PLEDs as ictal phenomena. Occurrence of PLEDs usually accompanied by decreased mentality and is improved as PLEDs disappeared. Current SPECT study showed marked hyperperfusion in the lesion side of PLEDs, that is striking evidence of PLEDs as ictal phenomena. Also careful review of EEG with PLEDs revealed it is a dynamic process rather than a static state. Despite of these evidences, as PLEDs are an end-stage of animal status epilepticus models, it may be a transition of ictal to interictal state.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.1
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• pp.17-23
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• 2009

The influence of different forming elements on the local paper structure and the related paper properties was investigated in this study. Specifically, a conventional papermaking foil system and a velocity induced drainage (VID) system were compared. The study involved the analysis of the product samples obtained from the commercial machine trials. The paper samples produced with VID forming systems showed better formation. The deterministic patter in the local structural profile map of the Foil samples indicated the structure of foil samples was more supple after forming process and then easier to be marked by various fabrics such as wet pressing fabric. The higher bulk was observed in the VID samples, which resulted in higher scattering coefficient, lower ZDT strength, and higher bending stiffness.

• BMB Reports
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• v.32 no.4
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• pp.326-330
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• 1999

An aspartase purified from Hafnia alvei was inactivated by diethylpyrocarbonate (DEP) in a pseudo-first-order inactivation. The first-order plot was biphasic. The inactivation process was not saturable and the second order rate constant was $1.3\;M^{-1}s^{-1}$. The inactivated aspartase was reactivated with NH₂OH. The difference absorption spectrum of DEP-inactivated vs native enzyme preparations revealed a marked peak around 242 nm. The pH dependence of the inactivation rate suggests that an amino acid residue having a pK value of 7.2 was involved in the inactivation. L-aspartate, fumarate (substrates), and chloride ion (inhibitor) protected the enzyme against inactivation, indicating that histidine residues for the enzyme activity are located at the active site of this aspartase. Inspection of the presence and absence of $Cl^-$ ion demonstrated that the number of essential histidine residues is less than two. Thus, one or two histidines are in or near the aspartate binding site and participate in an essential step of the catalytic reaction.

• Applied Microscopy
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• v.6 no.1
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• pp.1-7
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• 1976

To investigate the nature of typhoid cells, three cases of clinically, serologically and histopathologically proven typhoid lesions of the small intestine and regional lymph nodes were studied light and electron microscopically, Light microscopically, typhoid cells were swollen mononuclear cells characterized by abundant amount of eosinophilic cytoplasm and frequent phagocytoses of red blood cells, bacterial clumps and other tissue debris. These cells were pyronin negative, Electron microscopically, these cells showed marked and diffuse dilatation of RER cisternae and disappearance of ordinary cytoplasmic organelles, but frequent phagocytosed materials, The meaning and reason of RER cisternal dilatation and reduction of cytoplasmic organelles were discussed, and are regarded as degenerative process due to bacterial endotoxin. Although there was hot enough cytoplasmic organelles to pinpoint the origin of typhoid cells, active phagocytosis and evidences against being either plasmacytic or lymphocytic nature favored retuculoendothelial nature of the typhoid cells.

• Journal of Fashion Business
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• v.3 no.1
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• pp.138-146
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• 1999

For an enterprise to survive in extremely competitive world, it had better to down budget and resource of unimportant fields so that the enterprise can concentrate resources on the strong field. Nowadays in Korea, it is important to research outsourcing for strengthen the competitive power in apparel maker because of recent depression. The questionnaire was composed of 14 factors about outsourcing effect. The questionnaires were selected for finial analysis 67 apparel makers in Pusan and Seoul and data was analysed by using paired t-test by SPSS program. Almost of apparel makers (85.07%) has been outsourced the sewing process to contractor or vendor. Outsourcing in this case is marked lower effect than insourcing except reducing cost, economy of time and overcoming internal resources. This means that our outsourcing has been progressed with so many risk. If we have research the successful outsourcing and have a strategic vision and plan with vendor and product mutually beneficial relationship, we can share the risk and creating new business synergies through outsourcing.

• The Journal of Art Theory & Practice
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• no.6
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• pp.147-163
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• 2008

The 1960s is a decade that is marked by new concepts of art making and art appreciation. Starting from Fluxus, the new art in the 1960s such as Happenings and performance art pursued the process of art making as an integral part of artistic experience. The traditional concept of art works that only appeal to vision soon became a site of contentious experiments and innovations in which the experience of seeing is accompanied by other sensual encounters of sound, smell, touch, and taste. These attempts can be seen as a revolutionary move to restore the sense of corporeality to the act of seeing that has been disembodied by the way in which western art has built the unifying, homeogenous field of vision. This paper delves into the works of Fluxus artists - Daniel Spoerri, Ben Vautier, Alison Knowles, Ay-O, and Takako Saito - who were central figures in taking art into the new age of post-ocularcentrism. Exploring the sense of smell, touch, and taste, these artists led the viewer to participate in their art making with the incorporated vision.