• Title/Summary/Keyword: Repeated

Search Result 8,679, Processing Time 0.036 seconds

Production of Lactococcal Bacteriocin using Repeated-Batch and Continuous Cultures

  • Yoo, Jin-Young
    • Journal of Microbiology and Biotechnology
    • /
    • v.2 no.4
    • /
    • pp.284-287
    • /
    • 1992
  • Repeated-batch and continuous cultures of Lactococcus sp. 1112-1 were carried out for bacteriocin production using a glucose-casein medium. Repeated-batch culture did not efficiently enhanced the bacteriocin production. Continuous production was possible at the dilution rate of 0.4 $h^{-1}$. Maximum specific production rate ($Q^p$), bacteriocin production and biomass at the dilution rate were 347, 136 IU/g/h, 2, 121 IU/ml and 2.45 g/L, respectively.

  • PDF

NEW EXPRESSIONS FOR REPEATED LOWER TAIL INTEGRALS OF THE NORMAL DISTRIBUTION

  • Withers, Christopher S.;Nadarajah, Saralees
    • Journal of the Korean Statistical Society
    • /
    • v.36 no.3
    • /
    • pp.411-421
    • /
    • 2007
  • The recent work by the authors (see, Withers, 1999; Withers and McGavin, 2006; Withers and Nadarajah, 2006) provided new expressions for repeated upper tail integrals of the univariate normal density and so also for the general Hermite function. Here we derive new expressions for repeated lower tail integrals of the same. The calculations involve the use of Moran's L-function and the Airy function. In particular, the Hermite functions are expressed in terms of Moran's L-function and vice versa.

Comparison study on mode and response localization (모드국부화와 응답국부화의 비교연구)

  • 하동진;유홍희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2003.11a
    • /
    • pp.704-709
    • /
    • 2003
  • Vibration localization characteristics of repeated mistuned structures are investigated by two ways. The mistuning often creates significant response discrepancies among subcomponents of the repeated structures. As a result of the discrepancies, critical fatigue problems often occur in repeated structures. Therefore, it is of great importance to predict the vibration response of the mistuned repeated structures accurately. In this paper, a simplified model is employed and dimensionless parameters that influence the localization characteristics are first identified. Through the parameter study, the two localization phenomena are investigated and compared.

  • PDF

Analysis of Repeated Measurement Problem in SP data (SP 데이터의 Repeated Measurement Problem 분석)

  • CHO, Hye-Jin
    • Journal of Korean Society of Transportation
    • /
    • v.20 no.1
    • /
    • pp.111-119
    • /
    • 2002
  • One of the advantages of SP methods is the possibility of getting a number of responses from each respondent. However, when the repeated observations from each respondent are analysed by applying the simple modeling method, a potential problem is created because of upbiased significance due to the repeated observation from each respondent. This study uses a variety of approaches to explore this issue and to test the robustness of the simple model estimates. Among several different approaches, the Jackknife method and Kocurs method were applied. The Jackknife method was implemented using a program JACKKNIFE. The model estimate results of Jackknife method and Kocurs method were compared with those of the uncorrected estimates in order to test whether there was repeated measurement problem or not and the extent to which this problem affected the model estimates. The standard errors between the uncorrected model estimates and Jackknife estimates were also compared. The results reveals that the t-ratios of Kocurs are much lower than those of the uncorrected method and Jackknife estimates, indicating that Kocurs method underestimates the significance of the coefficients. Jackknife method produced the almost same coefficients as those of the uncorrected model but the lower t-ratios. These results indicate that the coefficients of the uncorrected method are accurate but that their significance are somewhat overestimated. In this study. 1 concluded that the repeated measurement Problem did exist in our data, but that it did not affect the model estimation results significantly. It is recommended that such a test should become a standard procedure. If it turns out that the analysis based on the simple uncorrected method are influenced by the repeated measurement problem. it should be corrected.

Repeated Reading Experiences of Adults: Centered on Lifelong Education Center Students at Chonbuk National University (성인의 반복독서 경험에 관한 연구 - 전북대학교 평생교육원 학생들을 중심으로 -)

  • Lee, Seung-Chae
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.45 no.1
    • /
    • pp.353-376
    • /
    • 2011
  • The goal of this study is to examine what kind of repeated-reading habits adults have, what sort of books they read repeatedly, and what preferences they have depending on their age or gender. A questionnaire was distributed to the students at Lifelong Education Center of Chonbuk National University to survey their repeated reading experiences. The results of the statistical analysis are as follows: 1) Most adults have experienced repeated reading. 2) Women have more experience with repeated reading than men, and in terms of age, more people in their forties read the same books repeatedly. 3) Most repeated readers read their books twice: Women tend to read their books repeatedly more than men do. 4) More than half of the adults in the sample group have read their favorite books several times. 5) The importance of books in this study was judged on the basis of the number of repeated readers and the frequency of reading. The order of important books is as follows: The Little Prince, The Tale of Three Kingdoms, The Giving Tree, The Greek and Roman Mythology, Meu Pe de Larania Lima, No Possession, Hope for the Flowers, and Demian. 6) More than half of the male repeated readers read The Tale of Three Kingdoms while female repeated readers tend to read a wider variety of books. 7) Adults read the same books repeatedly to enjoy and learn something.

Rheological properties and crystallization kinetics of polypropylene block copolymer with repeated extrusion

  • Sung Yu-taek;Seo Won Jin;Kim Jong Sung;Kim Woo Nyon;Kwak Dong-Hwan;Hwang Tae-Won
    • Korea-Australia Rheology Journal
    • /
    • v.17 no.1
    • /
    • pp.21-25
    • /
    • 2005
  • Rheological properties and crystallization kinetics of the polypropylene (PP) block copolymer and recycled PP block copolymer were studied by advanced rheometric expansion system (ARES), differential scanning calorimetry (DSC), and optical microscopy. In the study of the dynamic rheology, it is observed that the storage modulus and loss modulus for the PP block copolymer and recycled PP block copolymer did not change with frequency. In the study of the effect of the repeated extrusion on the crystallization rate, half crystallization time of the PP samples was increased with the number of repeated extrusion in isothermal crystallization temperature ($T_c$). From the isothermal crystallization kinetics study, the crystallization rate was decreased with the increase of the number of repeated extrusion. Also, from the result of Avrami plot, the overall crystallization rate constant (K) was decreased with the increase of the number of the repeated extrusion. From the study of the optical microscopy, the size of the spherulite of the PP samples did not change significantly with the number of repeated extrusion. However, it was clearly observed that the number of the spherulite growth sites was decreased with the number of repeated extrusion. From the results of the crystallization rate, isothermal crystallization kinetics, Avrami plots, and optical microscopy, it is suggested that the crystallization rate of the PP block copolymer is decreased with the increase of the number of repeated extrusion.

Analysis of Repeated Bone Graft after Secondary Bone Graft in Children with Alveolar Cleft (치조열에서 재 시행한 골이식의 분석)

  • Koh, Kyung Suck;Lee, Sung Wook;Choi, Jong Woo;Lee, Young Kyoo;Kwoun, Soon Man
    • Archives of Plastic Surgery
    • /
    • v.35 no.3
    • /
    • pp.273-278
    • /
    • 2008
  • Purpose: The most widely accepted protocol for alveolar cleft reconstruction is to repair it during the mixed dentition stage. There were lower resorption rate (about 88%) at this stage. However we found some cases that need repeated bone grafting. Therefore we sought to analyze the cause of repeated alveolar bone grafting in connection with other factors. Methods: From January 2000 to January 2006, thirty-nine secondary alveolar bone grafts with iliac crest spongiosa were carried out. In 39 patients, 5 patients who had significant bone graft resorption received repeated alveolar bone graft. In all the cases, the causes of repeated bone grafts were dental root exposure(angulation), and the deficiency of the bony support for lateral incisor or canine eruption. In 3 cases, there was deficiency of the alveolar bone at the cleft side. There was the need of repeated bone grafts for orthodontic treatment in 2 cases and for application of dental implants in 1 case. Results: During the follow-up period, the clinical and radiologic examinations showed that repeated alveolar bone grafts were maintained successfully without any complications. The volume of the repeated bone graft was sufficient for orthodontic treatment and implantation. Conclusion: The essential conditions for successful alveolar bone grafting includes the status of cleft sided teeth, further treatment and planed schedule, as well as canine eruption. Alveolar bone grafting has to be performed with difference of each case in mind.

Effects of Repeated Ovarian Stimulation on Ovarian Function and Aging in Mice

  • Whang, Jihye;Ahn, Cheyoung;Kim, Soohyun;Seok, Eunji;Yang, Yunjeong;Han, Goeun;Jo, Haeun;Yang, Hyunwon
    • Development and Reproduction
    • /
    • v.25 no.4
    • /
    • pp.213-223
    • /
    • 2021
  • Controlled ovarian hyperstimulation (COH) is routinely used in the in vitro fertilization and embryo transfer (IVF-ET) cycles to increase the number of retrieved mature oocytes. However, the relationship between repeated COH and ovarian function is still controversial. Therefore, we investigated whether repeated ovarian stimulation affects ovarian aging and function, including follicular development, autophagy, and apoptosis in follicles. Ovarian hyperstimulation in mice was induced by intraperitoneal injection with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Mice subjected to ovarian stimulation once were used as a control group and 10 times as an experimental group. Repeated injections with PMSG and hCG significantly reduced the number of primary follicles compared to a single injection. The number of secondary and antral follicles increased slightly, while the number of corpus luteum increased significantly with repeated injections. On the other hand, repeated injections did not affect apoptosis in follicles associated with follicular atresia. The expression of autophagy-related genes Atg5, Atg12, LC3B, and Beclin1, cell proliferation-related genes mTOR, apoptosis-related genes Fas, and FasL was not significantly different between the two groups. In addition, the expression of the aging-related genes Dnmt1, Dnmt3a, and AMH were also not significantly different. In this study, we demonstrated that repeated ovarian stimulation in mice affects follicular development, but not autophagy, apoptosis, aging in ovary. These results suggest that repetition of COH in the IVF-ET cycle may not result in ovarian aging, such as a decrease in ovarian reserve in adult women.

Behavior of RC Beams Strengthened with Carbon Fiber SheetsUnder Repeated Loading (단조 반복하중 하의 탄소섬유시트 보강 RC보의 거동에 관한 연구)

  • Park, Jeong Yong;Kim, Seong Do;Cho, Baik Soon;Cheung, Jin Hwan
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.10 no.4
    • /
    • pp.183-193
    • /
    • 2006
  • This study deals with the response of reinforced concrete beams strengthened with carbon fiber sheets. Test beams are subjected to static loading and repeated loading. Based on the static test results of the RC beams strengthened with carbon fiber sheets, repeated loading tests are performed. The variables of repeated loading test are composed of the number of carbon fiber sheets, the existence of U-shaped band at the end for anchoring, and loading rate of repeated loading, etc. Test results show the flexural behavior, the characteristics of strength, the characteristics of ductility, the change of flexural rigidity, and the amount of energy loss of RC beams under monotonic incremental loading and repeated loading. The failure strain of carbon fiber sheets is also estimated under repeated loading. From the experimental results, this work presents a basis of the data needed to analyze and design the static and dynamic flexural response of RC beams strengthened with carbon fiber sheets.

SECOND BEST TEMPORALLY REPEATED FLOWS

  • Eleonor, Ciurea
    • Journal of applied mathematics & informatics
    • /
    • v.9 no.1
    • /
    • pp.77-86
    • /
    • 2002
  • Ford and Fulkerson have shown that a stationary maximal dynamic flow can be obtained by solving a transhipment problem associated with the static network and thereby finding the maximal temporally repeated dynamic flow. This flow is known to be an optical dynamic flow. This paper presents an algorithm for second best temporal1y repeated flows. A numerical example is presented.