• Title/Summary/Keyword: 통계해석

Search Result 1,152, Processing Time 0.025 seconds

Change of Cerebral Blood Flow Distribution and Vascular Reserve according to Age in Koreans Measured by Tc-99m HMPAO Brain SPECT (한국 정상인에서 연령에 따른 뇌혈류분포와 혈류예비능의 변화: Tc-99m HMPAO SPECT에 의한 연구)

  • Song, Ho-Cheon;Bom, Hee-Seung;Sohn, Hye-Kyung;Jeong, Hwan-Jeong;Min, Jung-Jun;Kim, Ji-Yeul;Lee, Jae-Tae;Moon, Dae-Hyuk;Lee, Hee-Kyung
    • The Korean Journal of Nuclear Medicine
    • /
    • v.33 no.3
    • /
    • pp.247-261
    • /
    • 1999
  • Purpose: The aim of this study was to evaluate the normal values of regional cerebral blood flow (rCBF) and cerebrovascular reserve (CVR) in normal children to aged volunteers using Tc-99m HMPAO, Materials and Methods: Thirty four right-handed normal volunteers (20 males, 14 females, mean age $40.3{\pm}24.9$ years, range 4 to 82 years) were underwent rost/acetazolamide (ACZ) brain SPECT using Tc-99m HMPAO and the sequential injection and subtraction method. rCBF was estimated on the basis of a semiquantitative approach by means of right/left ratio, region/cerebellum and region to whole brain ratios in (rental, parietal, temporal, and occipital lobes, basal ganglia, thalami, and cerebellum. CVR was measured by means of % perfusion increase calculated as % mean count change compared to rest rCBF in each regions. Results: Mean values of right to left ratios range from 1.004 to 1.018, rCBF was highest in cerebellum and lowest in basal ganglia and thalami. Frontal and temporal rCBF decreased while occipital and thalamic rCBF increased according to age. No sexual difference of rCBF was noted. Mean CVR was $29.9{\pm}12.9%$. Mean CVR significantly increased to late teens, and declined thereafter. After 6th decade, CVR in both frontal lobes, left parietal lobe and right basal ganglia decreased significantly with advancing age. There was no sexual difference of CVR. Conclusion: Quantitative assessment of CVR was possible by ACZ Tc-99m HMPAO brain SPECT. It revealed that rCBF and CVR changed according to age in normal Korean volunteers. There was no sexual difference.

  • PDF

Analysis of the Characteristics of the Seismic source and the Wave Propagation Parameters in the region of the Southeastern Korean Peninsula (한반도 남동부 지진의 지각매질 특성 및 지진원 특성 변수 연구)

  • Kim, Jun-Kyoung;Kang, Ik-Bum
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.2 no.1 s.4
    • /
    • pp.135-141
    • /
    • 2002
  • Both non-linear damping values of the deep and shallow crustal materials and seismic source parameters are found from the observed near-field seismic ground motions at the South-eastern Korean Peninsula. The non-linear numerical algorithm applied in this study is Levenberg-Marquadet method. All the 25 sets of horizontal ground motions (east-west and north-south components at each seismic station) from 3 events (micro to macro scale) were used for the analysis of damping values and source parameters. The non-linear damping values of the deep and shallow crustal materials were found to be more similar to those of the region of the Western United States. The seismic source parameters found from this study also showed that the resultant stress drop values are relatively low compared to those of the Western United Sates. Consequently, comparisons of the various seismic parameters from this study and those of the United States Seismo-tectonic data suggest that the seismo-tectonic characteristics of the South eastern Korean Peninsula is more similar to those of the Western U.S.

Surgical Treatment of Pulmonary Atresia with Intact Ventricular Septum -Effect of the size of tricuspid valve annulus on the surgical outcome- (영아기에 발견된 심실중격이 온전한 폐동맥 폐쇄증의 외과적 수술요법 술전 삼첨판륜 크기 가 수술 결과에 미치는 영향)

  • 이정렬;윤태진
    • Journal of Chest Surgery
    • /
    • v.29 no.10
    • /
    • pp.1081-1089
    • /
    • 1996
  • Pulmonary atresia with intact ventricular septum has continued to have a high surgical mortality and morbidity. This mAy attribute to the non-uniformity of the anomaly. We reviewed a total of 34 infants with pulmonary atresla and intact ventricular septum managed in this hospital between 1987 and 1995. Mean age and body weight were 57.2 (range, 3-208) days and 4.1 (range, B.3∼6.8) kg. The preoperative Z-value of the diameter of the tricuspid valve was less than -2 in 85.2% of patients and less than -4 in 33. 3% . It is well correlated w th right ventricular cavity size (n=27. r10.68, p< 0.05). Coronary artery-right ventricular fistulas were identified in 3 patients, and right ventricular dependency was suspected in 1 Over All hospital mortality was 23.5%(8/34), although it decreased to 16.6%(4124) in 1990s. Subsequent procedures were performed in 6 patients between 3 days and 58 months after Initial palliation : one bidirectional cavopulmonary shunt and 1 Fontan operation after systemic-pulmonary shunt, 3 transannular patch + atrial septal defect closure and 1 additional systemic-pulmonary shunt after polmonary valvectomy or valvotomy. Changes of Z-values of the diameter of tricuspid valve have been followed up in 11 patients between 1 and 66 months postoperatively. Z-values were increased In 5 out of 8 transannular right ventriculAr outflow tract enlargement group and in 1 out of 3 pulmonary valvectomy or valvotomy group. Our data suggest that tailoring a treatment to right ventricular cavity size and coronary anom lies may improve the surgical outcome. A Z-value of the tricuspid valve diameter could be used.

  • PDF

The Effect of Perceived Risk, Scarcity Message in the CATV Homeshopping Ad, and Purchasing Experience on CATV Homeshopping Consumers Response (케이블 TV홈쇼핑 프로그램에서 지각된 위험과 희소성 메시지가 이용경험이 다른 소비자의 반응에 미치는 영향에 관한 연구)

  • Lee, Kyu-Wan;Koo, Ja-Eun
    • Korean journal of communication and information
    • /
    • v.32
    • /
    • pp.209-245
    • /
    • 2006
  • This study examines primarily the effects of perceived risk and scarcity massage on consumers in CATV homeshopping. For consumers, the perceived risk is the cause of delaying purchase decision in CATV Homeshopping while scarcity message in the Ad facilitate purchasing intention in the CATV homeshopping. And another important characteristic of consumer which exerts impact on the response of consumer to the Ad and the product is the frequency of purchasing experience. Thus the purpose of this study is to test the effect of 3 factors on consumer's response to homeshopping Ad and product: one is perceived risk, another is scarcity message and the third is consumer's difference in purchasing. And these are defined as independent variables. The responses of the consumer, the dependent variables of this test are measured in three dimensions; 1) the purchasing intention of the product, 2) the attitude toward the Ad, and 3) the attitude toward product of the consumer. 110 housewives are sampled and assigned to 4 experimental groups. All the groups first watched a video-taped homeshopping Ad messages, and then filled up their responses on the administered questionnaire. The results of this study shows as follows: 1) Perceived risk has negative effect to consumer response. 2) Scarcity message has positive effect to consumers response. 3) But especially perceived risk has negative effect to high frequency purchasing experience group. 4) Scarcity message has also negative effect to high frequency purchasing experience group. 5) The interaction effect of perceived risk and scarcity message is most prominent to the consumers of high frequent purchasing experience.

  • PDF

Automatic Detection of Stage 1 Sleep Utilizing Simultaneous Analyses of EEG Spectrum and Slow Eye Movement (느린 안구 운동(SEM)과 뇌파의 스펙트럼 동시 분석을 이용한 1단계 수면탐지)

  • Shin, Hong-Beom;Han, Jong-Hee;Jeong, Do-Un;Park, Kwang-Suk
    • Sleep Medicine and Psychophysiology
    • /
    • v.10 no.1
    • /
    • pp.52-60
    • /
    • 2003
  • Objectives: Stage 1 sleep provides important information regarding interpretation of nocturnal polysomnography, particularly sleep onset. It is a short transition period from wakeful consciousness to sleep. The lack of prominent sleep events characterizing stage 1 sleep is a major obstacle in automatic sleep stage scoring. In this study, utilization of simultaneous EEG and EOG processing and analyses to detect stage 1 sleep automatically were attempted. Methods: Relative powers of the alpha waves and the theta waves were calculated from spectral estimation. A relative power of alpha waves less than 50% or relative power of theta waves more than 23% was regarded as stage 1 sleep. SEM(slow eye movement) was defined as the duration of both-eye movement ranging from 1.5 to 4 seconds, and was also regarded as stage 1 sleep. If one of these three criteria was met, the epoch was regarded as stage 1 sleep. Results were compared to the manual rating results done by two polysomnography experts. Results: A total of 169 epochs were analyzed. The agreement rate for stage 1 sleep between automatic detection and manual scoring was 79.3% and Cohen’s Kappa was 0.586 (p<0.01). A significant portion (32%) of automatically detected stage 1 sleep included SEM. Conclusion: Generally, digitally-scored sleep staging shows accuracy up to 70%. Considering potential difficulty in stage 1 sleep scoring, accuracy of 79.3% in this study seems to be strong enough. Simultaneous analysis of EOG differentiates this study from previous ones which mainly depended on EEG analysis. The issue of close relationship between SEM and stage 1 sleep raised by Kinnari remains a valid one in this study.

  • PDF

Relationships between Fatty Acids and Tocopherols of Conventional and Genetically Modified Peanut Cultivars Grown in the United States (미국산 전통품종과 유전자 재조합 땅콩품종의 지방산과 토코페롤의 상관관계)

  • Shin, Eui-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.42 no.10
    • /
    • pp.1618-1628
    • /
    • 2013
  • Relationships between fatty acids and tocopherols in conventional and genetically modified peanut cultivars were studied by gas chromatography with flame ion detector and high performance liquid chromatography with fluorescence detection. Eight fatty acids and four tocopherol isomers in the sample set were identified and quantified. Oleic acid and linoleic acid are major fatty acids and the ratio of oleic and linoleic acids ranged from 1.11 to 16.26. Tocopherols contents were 6.76 to 12.24 for ${\alpha}$-tocopherol (T), 0.08 to 0.39 for ${\beta}$-T, 5.28 to 15.02 for ${\gamma}$-T, and 0.17 to 1.17 mg/100 g for ${\delta}$-T. Correlation coefficient (r) for fatty acids and tocopherols indicated a strong inverse relationship between oleic & linoleic acids (r=-0.97, P<0.05) and positive relationships between palmitic & linoleic acids (r=0.95, P<0.05) and ${\gamma}$-T & ${\delta}$-T (r=0.83, P<0.05). Principal component analysis (PCA) of fatty acids and tocopherols gave four significant principal components (PCs, with eigenvalues>1), which together account for 85.49% of the total variance in the data set with PC1 and PC2 contributing 45.27% and 21.33% of the total variability, respectively. Eigen analysis of the correlation matrix loadings of the four significant PCs revealed that PC1 was mainly contributed by palmitic, oleic, linoleic, and gondoic acids, while PC2 was by behenic acid, ${\beta}$-T, and ${\gamma}$-T. The score plot generated by PC1-PC2 identified sample clusters in the two spatial planes based on the oleic and linoleic acids. The score plot PC3-PC4 didn't separate sample groups.

Clinical Outcome after Treatment with the First-line Drugs in Patients with Persistent Positive Sputum Smear and Negative Sputum Culture Results (지속적인 객담 도말양성 및 배양음성인 폐결핵환자에서 일차항결핵제로 치료종결한 후의 임상성적)

  • Kwon, Eun-Su;Lee, Jong-Youk
    • Tuberculosis and Respiratory Diseases
    • /
    • v.51 no.4
    • /
    • pp.325-333
    • /
    • 2001
  • Background : This study aimed to estimate the clinical outcome and identify the characteristics of a group of patients with pulmonary tuberculosis who completed anti-tuberculosis therapy with the First-line drugs in spite of having positive smear results with negative sputum culture results over the previous six months. Method : A retrospective chart review of 21 patients who fulfilled the above criteria between 1995 and 1999 was performed. The laboratory data as well as the clinical data of the patients with positive smear results and negative culture results over a six months period were reviewed. Results : The negative conversion of sputum culture results was achieved within $1.3{\pm}1.2$ months and the negative conversion of the sputum smear results was accomplished during $9.5{\pm}3.3$ months. Chest X-rays at 5 months following the institution of anti-tuberculosis therapy from all patients revealed improvements. Four out of 21 patients(19%) relapsed during the follow up, $15.2{\pm}13.4$ months after administering anti-tuberculosis therapy for $13.3{\pm}3.1$ months. Relapses were confirmed from between 3 months and 4 months after the treatment completion. Only one of the four relapses had no past history of anti-tuberculosis therapy and the others had prior treatment twice (p<0.01). The period of anti-tuberculosis treatment was extended to a mean of $4.6{\pm}2.6$ months in 12 patients. However, prolongation of anti-tuberculosis therapy had no affect on the relapse rate (odds ratio, 95% CI 0.18, 2.15). Conclusion : Prolongation of therapy with the First-line drugs is not necessary for patients with persistently positive smear results over 6 months and negative culture results. A patient who has had prior anti-tuberculosis therapy more than twice should be paid the closest attention.

  • PDF

Analysis of Factors Influencing Entrepreneurial Performance at the University Level for Becoming Entrepreneurial Universities (기업가형 대학(Entrepreneurial University)을 위한 대학의 창업 성과 영향요인 분석)

  • Lim, Hanryeo;Hon, Sungpyo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.15 no.2
    • /
    • pp.19-32
    • /
    • 2020
  • The purpose of this study was to investigate the influence factors of the university level centering on the entrepreneurial performance of the university students and full-time faculties in the situation of increasing interest in entrepreneurial university. In order to achieve the purpose of the study, a panel data was established from 2015 to 2018 on the basis of the university notification data. The panel data included universities with data on the number of university students and full-time faculty founders for at least two years. Through this, four year data from 154 universities were used for analysis. As an analysis method, frequency analysis and descriptive statistics were conducted to understand the characteristics of the university. Since then, panel negative binomial regression analysis has been conducted in consideration of the longitudinal features and distribution of the data. Also, based on the Hausman test results, the results were interpreted based on random effect model. The results of this study are as follows. First, as a result of the analysis of the entrepreneurial performance and the change trend of the domestic university from 2015 to 2018, the entrepreneurial performance of the university has been steadily increasing in the last four years, and the increase in the number of university student entrepreneurs was relatively higher than the full-time faculties. Second, economic and educational approaches need to be combined to promote university students' start-ups. The university factors that promote the start-up of university students were found to be scholarships, start-up grants, startup lectures, and startup clubs. Third, the openness and regional characteristics of the univeristy can promote the establishment of university students. Fourth, the establishment of a research environment and support for start-ups for full-time faculty members can enhance their start-up performance. The university factors that promote the start-up of full-time faculty were research funds and staffes who support start-up. The conclusions drawn from these findings are as follows. First, overall efforts are needed to develop into an entrepreneurial university. Second, in order to change into an entrepreneurial university, direct support for entrepreneurship is needed. Third, as an entrepreneurial university, it is necessary to find a way to bridge the gap by university according to region and size. Fourth, it is necessary to reinforce the support for linking the research results of universities to start-ups. Fifth, it is necessary to improve the atmosphere for full-time faculty members to be entrepreneur.

Studies on Deacidification of Citrus Fruit and Juice for Juice Products by Heating Treatment and Electrodialysis (열처리 및 전기투석에 의한 초기수확 밀감의 탈산에 관한 연구)

  • Ko Won-Joon;Yang Min-Ho;Kang Yeung-Joo
    • Food Science and Preservation
    • /
    • v.13 no.2
    • /
    • pp.144-153
    • /
    • 2006
  • The effects on deacidification of citrus fruits produced at early harvesting season for juice products were examined by heating treatment of raw fruits and electrodialysis of juice. Weight and total acidities were decreased by heating treatment for 40 hr at $25^{\circ}C,\;30^{\circ}C,\;35^{\circ}C\;and\;40^{\circ}C$, but $^{\circ}Brix$ and pH increased Sugar to acid ratio also increased. Total acidities were decreased from 1.25 (Oct30, 2004), 1.24 (Nov.5, 2004), 0.99 (Nov.13, 2004) and 0.98% (Nov.19, 2004) to 0.48 (Oct30, 2004), 0.51 (Nov.05, 2004), 0.37 (Nov.13, 2004) and 0.42% (Nov.19, 2004) by electrodialysis for 100 min respectively, and $^{\circ}Brix$ also slightly decreased, but solid to acid ratio was increased as a result. However pH and color remained almost unchanged by electodialysis. Also, free sugar contents of citrus juice little were changed, but organic acid content were decreased fairly. Narirutin and hesperidin content among flavonoids were slightly decreased by electrodialysis, but they were not significantly different. $K^+,\;PO_4^{2-},\;SO_4^{2-}\;and\;Cl^-$ content were decreased by electrodialysis, and $K^+$ contents decreased by more than 80% However, $Na^+$ consent was increased by about 2 times. Total polyphenol contents and electron donating abilities were decreased a little by electrodialysis but nitrite scavenging abilities were little changed. By acceptability test citrus juice prepared by electrodialysis for 100 min was superior to original citrus juice.

Assessment of CO2 Geological Storage Capacity for Basalt Flow Structure around PZ-1 Exploration Well in the Southern Continental Shelf of Korea (남해 대륙붕 PZ-1 시추공 주변 현무암 대지 구조의 CO2 지중저장용량 평가)

  • Shin, Seung Yong;Kang, Moohee;Shinn, Young Jae;Cheong, Snons
    • Economic and Environmental Geology
    • /
    • v.53 no.1
    • /
    • pp.33-43
    • /
    • 2020
  • CO2 geological storage is currently considered as the most stable and effective technology for greenhouse gas reduction. The saline formations for CO2 geological storage are generally located at a depth of more than 800 m where CO2 can be stored in a supercritical state, and an extensive impermeable cap rock that prevents CO2 leakage to the surface should be distributed above the saline formations. Trough analysis of seismic and well data, we identified the basalt flow structure for potential CO2 storage where saline formation is overlain by basalt cap rock around PZ-1 exploration well in the Southern Continental Shelf of Korea. To evaluate CO2 storage capacity of the saline formation, total porosity and CO2 density are calculated based on well logging data of PZ-1 well. We constructed a 3D geological grid model with a certain size in the x, y and z axis directions for volume estimates of the saline formation, and performed a property modeling to assign total porosity to the geological grid. The estimated average CO2 geological storage capacity evaluated by the U.S. DOE method for the saline formation covered by the basalt cap rock is 84.17 Mt of CO2(ranges from 42.07 to 143.79 Mt of CO2).