• Title/Summary/Keyword: Counts Rate

Search Result 495, Processing Time 0.05 seconds

The Application of a Pulsed Photostimulated Luminescence (PPSL) Method for the Detection of Irradiated Foodstuffs

  • Yi, Sang-Duk;Yang, Jae-Seung
    • Preventive Nutrition and Food Science
    • /
    • v.5 no.3
    • /
    • pp.136-141
    • /
    • 2000
  • The properties of pulsed photostimulated luminescence (PPSL) were measured to use as basis data for the detection of irradiated foodstuffs (34 different foods). Samples were packed in polyethylene bags and irradiated at 1, 5, and 10 kGy with a dose rate of 10 kGy/h. The samples irradiated were introduced in the sample chamber without other preparation and measured PPSL photon counts for 60 and 120 s. The PPSL photo counts of the irradiated samples were higher than the unirradiated, increased with increasing irradiation dose, and showed a good relationship between irradiation doses and photon counts in a multinomial expression. These results suggest that the detection of irradiated foodstuffs was possible by PPSL. Therefore, PPSL can be proposed as the method for the detection of irradiated foodstuffs.

  • PDF

Joint Modeling of Death Times and Counts with Covariate (공변량을 포함한 사망시간과 치료횟수의 결합모형의 개발)

  • Park, Hee-Chang;Park, Jin-Pyo
    • Journal of the Korean Data and Information Science Society
    • /
    • v.9 no.2
    • /
    • pp.149-158
    • /
    • 1998
  • In this paper we suggest the joint model of death times and counts with covariates. We assume that the death times follow a Weibull distribution with rate that depends on covariates. For the counts, a Poisson process is assumed with the intensity depending on time and the covariates. We obtain the maximum likelihood estimators of model parameters. This model is applied to data set of patients with breast cancer who received a bone marrow transplant.

  • PDF

Joint Modeling of Death Times and Counts Using a Random Effects Model

  • Park, Hee-Chang;Klein, John P.
    • Journal of the Korean Data and Information Science Society
    • /
    • v.16 no.4
    • /
    • pp.1017-1026
    • /
    • 2005
  • We consider the problem of modeling count data where the observation period is determined by the survival time of the individual under study. We assume random effects or frailty model to allow for a possible association between the death times and the counts. We assume that, given a random effect, the death times follow a Weibull distribution with a rate that depends on some covariates. For the counts, given the random effect, a Poisson process is assumed with the intensity depending on time and the covariates. A gamma model is assumed for the random effect. Maximum likelihood estimators of the model parameters are obtained. The model is applied to data set of patients with breast cancer who received a bone marrow transplant. A model for the time to death and the number of supportive transfusions a patient received is constructed and consequences of the model are examined.

  • PDF

A Study on Developing a Prediction Model of Patent Citation Counts (특허인용 예측모형 구축에 관한 연구)

  • Yoo, Jae-Bok;Chung, Young-Mee
    • Journal of the Korean Society for information Management
    • /
    • v.27 no.4
    • /
    • pp.239-258
    • /
    • 2010
  • The purpose of this study is to develop a prediction model of patent citation counts based on major factors which affect patent citation. To this end, we performed multiple regression analysis between the patent citation counts and five explanatory variables such as the number of pages, the number of claims, the reference-average-citation rate, the strength of bibliographic coupling, and the document similarity proved as having 5% or more standardized variances($r^2$) with patent citation counts, with a test dataset of U.S. patents in five subject fields. As a result, our prediction models showed 58.3% to 89.6% predictability depending on subject fields and revealed the document similarity has the highest impact on citation counts among the five predictive variables in all the subject fields. The result of comparison between the predicted citation counts and the actual ones confirmed the usefulness of the citation prediction models built for each subject field.

The Effects of Anti-histamine and Leukotriene Receptor Antagonist Against Ischemia-Reperfusion Injury (허혈-재관류 손상에서 히스타민 차단제와 류코트리엔 수용체 길항제의 효과 비교)

  • Cho, Hye-In;Chang, Hak;Kim, Suk-Wha
    • Archives of Reconstructive Microsurgery
    • /
    • v.21 no.1
    • /
    • pp.61-67
    • /
    • 2012
  • Purpose: The purpose of this study was to investigate the role of mast cells and their product, histamine and leukotriene in ischemia-reperfusion injury. Methods: Forty Sprague-Dawley rats were divided into four groups. (Group I: Control group without ischemia, Group II: Normal saline with ischemia, Group III: Cimetidine with ischemia, Group IV: Zafirlukast with ischemia) Skin flap was elevated and ischemic insult was given by clamping the artery for 12 hours. Before reperfusion, the rats were treated with saline, cimetidine and zafirlukast. Flap survival was evaluated at 7 days. Neutrophil counts, mast cell counts were evaluated 24 hours after reperfusion. Results: Flap survival rate in the control group was 92.33%, whereas normal saline group had 37.34% survivals. Cimetidine and zafirlukast treated group showed significantly higher survival rates than normal saline group. The neutrophil and mast cell counts in cimetidine and zafirlukast treated group were significantly decreased than normal saline group. Cimetidine treated group showed higher survival rate and lower cell counts than zafirlukast treated group. Conclusion: The administration of cimetidine and zafirlukast can decrease neutrophils and mast cells caused by ischemia-reperfusion and increase flap survivals. It is suggests that antihistamine and leukotriene receptor antagonist have protective effect against ischemia-reperfusion injury to skin flap in rat.

  • PDF

Effects of Dietary Cellulose Levels on Growth, Nitrogen Utilization, Retention Time of Diets in Digestive Tract and Caecal Microflora of Chickens

  • Cao, B.H.;Zhang, X.P.;Guo, Y.M.;Karasawa, Y.;Kumao, T.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.16 no.6
    • /
    • pp.863-866
    • /
    • 2003
  • This study was conducted to examine the effects of dietary cellulose levels on growth, nitrogen utilization, the retention time of diets in the digestive tract, and caecal microflora of 2-month-old Single Comb White Leghorn male chickens fed 3 purified diets that contained 0, 3.5% and 10% cellulose in equal amount of nutrients for 7 days. Body weight gain and nitrogen utilization were significantly higher (p<0.05), while total microflora counts in the caecal contents and retention time of the diet in the digestive tract were significantly lower (p<0.05) in the group fed 3.5% dietary cellulose compared with the group fed 10% dietary cellulose. Body weight gain, nitrogen utilization and retention time of the diet in the digestive tract decreased significantly while the total microflora count in the caecal contents increased significantly in the group fed 10% dietary cellulose compared to the group fed 0% dietary cellulose (p<0.05). Chickens fed 10% dietary cellulose had significantly increased counts of uric acid-degradative bacteria such as Peptococcaceae and Eubacterium, including Peptostreptococcus (p<0.05). The results suggest that cellulose in purified diets is an effective ingredient and the effects on growth, nitrogen utilization, caecal microflora counts and diet retention time in the digestive tract are dependent on the inclusion rate. Positive or negative effects of dietary cellulose are displayed by growth, nitrogen utilization, caecal microflora counts and retention time of the diet in the digestive tract. Positive effects were displayed when the inclusion rate is 3.5% and negative effects were displayed when that is greater than 3.5% of the diet, and the phenomenon is without reference to the age of the chickens.

A Study on the Characteristics of Water Quality for Groundwater and Purified Water of Several Schools in Gyeongsangbukdo Province (경상북도지역 학교지하수 및 정수기통과수의 수질특성에 관한 연구)

  • Kim, Suk-Chan;Bae, Hun-Kyun
    • Journal of Environmental Science International
    • /
    • v.20 no.5
    • /
    • pp.575-580
    • /
    • 2011
  • This study characterized water quality of groundwater and purified water used for drinking water in 30 schools in Gyeongsangbukdo Province. The results of the study showed that 43% of groundwater and 45% of purified water were not suitable for drinking. Among them, microbial contaminations were the most serious problem. In raw groundwater, the exceeding rates of total colony counts was the highest in August (53.6%). Purified water samples showed higher rate of exceeding drinking water standard for total colony counts while showing lower rate of exceeding drinking water standard for total coliforms and fecal coliforms in March and August. Overall, proper managements for microbial contaminations are required for both groundwater and purified water. Furthermore, special attention should toward students not to drink water when groundwater or purified water exceeds the drinking water quality standard.

A Study on the Spermatotoxicity Evaluation in Rats (랫트를 이용한 정자독성평가 연구)

  • 정문구;김종춘
    • Toxicological Research
    • /
    • v.11 no.1
    • /
    • pp.69-75
    • /
    • 1995
  • The present study was carried out to establish several spermatotoxicity test methods. For this purpose we investigated following parameters in the fertility study of DA-125, a new anticancer agent, in rats: testicular spermatid counts, epididymal sperm counts, daily sperm production rate, sperm morphology, and serum testosterone concentration. Motility and velocity of sperms were also measured using non-treated rats. At 0.3 mg DA-125/kg, spermatids per 1g testis and daily sperm production rate per 1g testis were significantly decreased, when compared with those of control group. Several types of abnormal sperms, such as no head, pin head, double head, hook at wrong angle, no tail, and small sperm, were found in both treated and control groups at a low frequency. Serum testosterone concentration at 0.3 mg DA-125/kg was close to the control value. Sperm motility and velocity measured with non-treated rats were in a good agreement with the results of other investigators. In our study established spermatotoxicity test methods can be used as a tool not only for the close examination of the cause of drug- or chemical-induced infertility, but also for the effective evaluation of reproductive toxicity.

  • PDF

Neutron Count Rate Measurement of $UO_2$ powder by Neutron Source

  • Kang Hee-Young;Koo Gil-Mo;Ha Jang-Ho;Kim Ho-Dong;Yang Myung-Seung
    • Proceedings of the Korean Radioactive Waste Society Conference
    • /
    • 2005.06a
    • /
    • pp.344-349
    • /
    • 2005
  • Neutron count rate measurements to assay fissile content of uranium powder have been carried out in a neutron counter. The induced fission neutrons by Cf-252 neutron source are counted as the variation of fissile material in fuel material. The measured counts are compared with equivalent results obtained from calculation. It shows that the measured neutron counts versus quantity of $UO_2$ powder enrichment agreed reasonably well with the calculated values.

  • PDF

A study of feedback resister series effects for stabilizing the gain of the photomultiplier with counting rate increase (계수율 증가에 따른 광증배관의 이득안정을 위한 궤환저항 효과에 관한 연구)

  • 천희영;신현국
    • 전기의세계
    • /
    • v.29 no.7
    • /
    • pp.455-459
    • /
    • 1980
  • The gain change of the photomultiplier which occurs as the count rate increased was examined. and simple feedback resistor series was introduced between 7th and 9th dynode for compensating the gain change. The effect of the feedback resistor series was considerably good to reduce the gain change. With the feedback resistor, the gain change was only 1.9%, when count rate was increased from 514 CPS (counts per second) to 1250 CPS. Without the feedback resister, the gain change was 6.9%, when the count rate was increased from 530 CPS to 1250 CPS.

  • PDF