• Title/Summary/Keyword: statistical analysis.

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Simulation of Drying Grain with Solar-Heated Air (태양에너지를 이용한 곡물건조시스템의 시뮬레이션에 관한 연구)

  • Keum, Dong-Hyuk
    • Journal of Biosystems Engineering
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    • v.4 no.2
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    • pp.64-64
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    • 1979
  • Low-temperature drying systems have been extensively used for drying cereal grain such as shelled corn and wheat. Since the 1973 energy crisis, many researches have been conducted to apply solar energy as supplemental heat to natural air drying systems. However, little research on rough rice drying has been done in this area, especially very little in Korea. In designing a solar drying system, quality loss, airflow requirements, temperature rise of drying air, fan power and energy requirements should be throughly studied. The factors affecting solar drying systems are airflow rate, initial moisture content, the amount of heat added to drying air, fan operation method and the weather conditions. The major objectives of this study were to analyze the effects of the performance factors and determine design parameters such as airflow requirements, optimum bed depth, optimum temperature rise of drying air, fan operation method and collector size. Three hourly observations based on the 4-year weather data in Chuncheon area were used to simulate rough rice drying. The results can be summarized as follows: 1. The results of the statistical analysis indicated that the experimental and predicted values of the temperature rise of the air passing through the collector agreed well.2. Equilibrium moisture content was affected a little by airflow rate, but affected mainly by the amount of heat added, to drying air. Equilibrium moisture content ranged from 12.2 to 13.2 percent wet basis for the continuous fan operation, from 10.4 to 11.7 percent wet basis for the intermittent fan operation respectively, in range of 1. 6 to 5. 9 degrees Centigrade average temperature rise of drying air.3. Average moisture content when top layer was dried to 15 percent wet basis ranged from 13.1 to 13.9 percent wet basis for the continuous fan operation, from 11.9 to 13.4 percent wet basis for the intermittent fan operation respectively, in the range of 1.6 to 5.9 degrees Centigrade average temperature rise of drying air and 18 to 24 percent wet basis initial moisture content. The results indicated that grain was overdried with the intermittent fan operation in any range of temperature rise of drying air. Therefore, the continuous fan operation is usually more effective than the intermittent fan operation considering the overdrying.4. For the continuous fan operation, the average temperature rise of drying air may be limited to 2.2 to 3. 3 degrees Centigrade considering safe storage moisture level of 13.5 to 14 perceut wet basis.5. Required drying time decrease ranged from 40 to 50 percent each time the airflow rate was doubled and from 3.9 to 4.3 percent approximately for each one degrees Centigrade in average temperature rise of drying air regardless of the fan operation methods. Therefore, the average temperature rise of drying air had a little effect on required drying time.6. Required drying time increase ranged from 18 to 30 percent approximately for each 2 percent increase in initial moisture content regardless of the fan operation methods, in the range of 18 to 24 percent moisture.7. The intermittent fan operation showed about 36 to 42 percent decrease in required drying time as compared with the continuous fan operation.8. Drymatter loss decrease ranged from 34 to 46 percent each time the airflow rate was doubled and from 2 to 3 percent approximately for each one degrees Centigrade in average temperature rise of drying air, regardless of the fan operation methods. Therefore, the average temperature rise of drying air had a little effect on drymatter loss. 9. Drymatter loss increase ranged from 50 to 78 percent approximately for each 2 percent increase in initial moisture content, in the range of 18 to 24 percent moisture. 10. The intermittent fan operation: showed about 40 to 50 percent increase in drymatter loss as compared with the continuous fan operation and the increasing rate was higher at high level of initial moisture and average temperature rise.11. Year-to-year weather conditions had a little effect on required drying time and drymatter loss.12. The equations for estimating time required to dry top layer to 16 and 1536 wet basis and drymatter loss were derived as functions of the performance factors. by the least square method.13. Minimum airflow rates based on 0.5 percent drymatter loss were estimated.Minimum airflow rates for the intermittent fan operation were approximately 1.5 to 1.8 times as much as compared with the continuous fan operation, but a few differences among year-to-year.14. Required fan horsepower and energy for the intermittent fan operation were3. 7 and 1. 5 times respectively as much as compared with the continuous fan operation.15. The continuous fan operation may be more effective than the intermittent fan operation considering overdrying, fan horsepower requirements, and energy use.16. A method for estimating the required collection area of flat-plate solar collector using average temperature rise and airflow rate was presented.

Development and Application of a Methodologyfor Climate Change Vulnerability Assessment-Sea Level Rise Impact ona Coastal City (기후변화 취약성 평가 방법론의 개발 및 적용 해수면 상승을 중심으로)

  • Yoo, Ga-Young;Park, Sung-Woo;Chung, Dong-Ki;Kang, Ho-Jeong;Hwang, Jin-Hwan
    • Journal of Environmental Policy
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    • v.9 no.2
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    • pp.185-205
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    • 2010
  • Climate change vulnerability assessment based on local conditions is a prerequisite for establishment of climate change adaptation policies. While some studies have developed a methodology for vulnerability assessment at the national level using statistical data, few attempts, whether domestic or overseas, have been made to develop methods for local vulnerability assessments that are easily applicable to a single city. Accordingly, the objective of this study was to develop a conceptual framework for climate change vulnerability, and then develop a general methodology for assessment at the regional level applied to a single coastal city, Mokpo, in Jeolla province, Korea. We followed the conceptual framework of climate change vulnerability proposed by the IPCC (1996) which consists of "climate exposure," "systemic sensitivity," and "systemic adaptive capacity." "Climate exposure" was designated as sea level rises of 1, 2, 3, 4, and 5 meter(s), allowing for a simple scenario for sea level rises. Should more complex forecasts of sea level rises be required later, the methodology developed herein can be easily scaled and transferred to other projects. Mokpo was chosen as a seaside city on the southwest coast of Korea, where all cities have experienced rising sea levels. Mokpo has experienced the largest sea level increases of all, and is a region where abnormal high tide events have become a significant threat; especially subsequent to the construction of an estuary dam and breakwaters. Sensitivity to sea level rises was measured by the percentage of flooded area for each administrative region within Mokpo evaluated via simulations using GIS techniques. Population density, particularly that of senior citizens, was also factored in. Adaptive capacity was considered from both the "hardware" and "software" aspects. "Hardware" adaptive capacity was incorporated by considering the presence (or lack thereof) of breakwaters and seawalls, as well as their height. "Software" adaptive capacity was measured using a survey method. The survey questionnaire included economic status, awareness of climate change impact and adaptation, governance, and policy, and was distributed to 75 governmental officials working for Mokpo. Vulnerability to sea level rises was assessed by subtracting adaptive capacity from the sensitivity index. Application of the methodology to Mokpo indicated vulnerability was high for seven out of 20 administrative districts. The results of our methodology provides significant policy implications for the development of climate change adaptation policy as follows: 1) regions with high priority for climate change adaptation measures can be selected through a correlation diagram between vulnerabilities and records of previous flood damage, and 2) after review of existing short, mid, and long-term plans or projects in high priority areas, appropriate adaptation measures can be taken as per this study. Future studies should focus on expanding analysis of climate change exposure from sea level rises to other adverse climate related events, including heat waves, torrential rain, and drought etc.

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The Effect of Polypropylene Mulching Method on Growth of Quercus glauca Thunb. Seedling and Weed Treatments (부직포 멀칭 방식에 따른 종가시나무 묘목의 생장과 제초에 미치는 영향)

  • Sung, Chang-Hyun;Yoon, Jun-Hyuck;Jin, Eon-Ju;Bae, Eun-Ji
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.5
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    • pp.59-66
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    • 2020
  • Recently, cultivation and management technologies have been needed to adapt due to climate change, which is causing abnormal weather conditions. One technique is to increase the utilization of evergreen broad-leaved species with high ornamental value. A total of five treatments were installed (1m×22.5m), including 60g/㎡ and 80g/㎡ using two types mulching material with an overlapping and hole-drilling mulching method and these were compared to un-mulching treatment a total of planted 92㎡ attheWol-aTestSiteForestattheForestforBiomaterialsResearchCenterinJinju-si, Gyeongsangnam-dofor 10monthsusing3-years-oldQuercusglaucaThunb. In comparison with the control site, the 60g/㎡ overlapping method was about 1.9 times higher than the root collar diameter, but there was no statistical significance between the treatments. Healthy seedlings were found to meet these conditions due to high biomass values and below and T/R ratios of 3.0 or lower and H/D ratios of 7.0 or lower. Comparing the values of LWR, SWR, and RWR, which can be evaluated for seedling due to the mulching treatments, as compared to the control, the growth of the ground areas including leaves and stems was enhanced, but the growth of the underground areas containing roots tended to have high control values. Based on this, the SQI value, which can be evaluated for the comprehensive quality of seedlings, was found to be significantly different between the control site and the mulching treatment sites, confirming that the growth and growth improvement effects were achieved with mulching treatments. The chlorophyll content analysis showed that there was a significant difference from the control site, and it was judged that weed generation in the control acted as an environmental stress, causing a decrease in chlorophyll content. It was found that the overlapping 80g/㎡ of polypropylene mulching material generated about 4 times fewer weeds than the control, and the manpower required for the mulching test field and weeding were equal at 3.3 people/100㎡/1 day. Mulching treatments have demonstrated a significant difference in the promotion of growth and quality of the seedlings and are judged as an alternative that can reduce the economic burden incurred by the purchase of the supplies and the manpower required to weed forestry plantations.

Comparison of Arthroscopic versus Mini Open Repair in Rotator Cuff Tear (회전근 개 파열에 대한 관절경적 봉합술과 소 절개 봉합술의 비교)

  • Park, Ji-Kang;Park, Kyoung-Jin;Kim, Yong-Min;Kim, Dong-Soo;Choi, Eui-Sung;Shon, Hyun-Chul;Cho, Byung-Ki;Im, Se-Hyuk
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.9 no.1
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    • pp.35-40
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    • 2010
  • Purpose: To compare the outcome of patients who underwent rotator cuff repair using all-arthroscopic mini-open repair techniques. Materials and Methods: We retrospectively reviewed 44 patients who underwent either arthroscopic (group I) or mini-open (group II) rotator cuff repair. 23 patients underwent an arthroscopic repair and 21 patients had a mini-open repair. The mean age was 50.4 years in the arthroscopic group and 56.7 years in the mini-open group. The outcomes for the 2 groups were evaluated using ROM, VAS, ASES, UCLA scale. Statistical analysis was performed using correlations, T-test, Paired T-test. The mean follow-up period in the arthroscopic and mini-open groups were 24.1months and 26.1months, respectively. Results: The group I (arthroscopic group) had 2 small-sized tears, 10 medium sized tears, and 11 large sized tears (3~5 cm). The group II (mini-open group) had 1 small sized tears, 8 medium sized tears, and 12 large sized tears. The mean cuff tear size of the group I and Group II were 3.8 cm and 4.2 cm, respectively. At last follow-up periods, ROM and functional scores were improved. In the group I and group II, there were no significant difference in ROM, VAS, ASES, UCLA score. Conclusion: The size of the tear did not produce different results at arthroscopic repair group but larger tear size was associated with a worse outcome in mini-open group. There were no significant clinical results between the arthroscopic and mini-open group.

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Tibial Torsion in Children of the Jeju Area (제주지역 소아의 경골 염전)

  • Song, Dong Ho;Eun, Baik-Lin;Park, Sang Hee;Lee, Joon Young;Tockgo, Young Chang
    • Clinical and Experimental Pediatrics
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    • v.48 no.1
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    • pp.75-80
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    • 2005
  • Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.

Clinical significance of follow-up laboratory tests, performed at 6 weeks after the onset of Kawasaki disease (가와사끼병에서 발병 6주째에 시행하는 추적검사의 임상적 유용성에 관한 고찰)

  • Oh, Il Ji;Moon, Kyung Hee;Hong, Myung Eun;Kim, Yeon Soon;Lee, Chang Woo;Yoon, Hyang Suk
    • Clinical and Experimental Pediatrics
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    • v.49 no.6
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    • pp.672-676
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    • 2006
  • Purpose : Low dose aspirin is used due to its antiplatelet effect for the subacute phase of Kawasaki disease(KD). It is usually used for 6-8 weeks, then various hematologic laboratory tests and follow up echocardiography for evaluating coronary abnormalities are performed. Our review investigated the usefulness of various follow up laboratory tests performed at 6 weeks after the onset of KD. Methods : Two hundred eighty-two children diagnosed and hospitalized with KD were identified by reviewing patient's charts. Cases which were diagnosed between January 1997 and December 2004 were included in this study. We reviewed laboratory data including leukocytes, platelet counts, antistreptolysin O(ASO), erythrocyte sedimentation rate(ESR), C-reactive protein(CRP), aspartate aminotransferase(AST), alanine aminotransferase(ALT), urinalysis, and echocardiograms performed at admission and 6 weeks after the onset of KD. Paired t-test and Fisher's exact test, as well as logistic regression tests, were used for the statistical analysis. Results : At 6th week data, ESR and CRP were still elevated in 35(12.4 percent) and 12(4.3 percent) patients, respectively. Sterile pyuria were all normalized. But, 36 patients(12.8 percent) showed thrombocytosis, 22(7.8 percent) elevated AST, 15(5.3 percent) leukocytosis, and 6(2.1 percent) coronary abnormalities. Coronary abnormalities at the 6th week were only shown in patients with initial abnormalites. Younger age and initial thrombocytosis were risk factors for thrombocytosis at the 6th week. Conclusion : All children with initial coronary abonormalites should have an echocardiogram at 6 weeks after the onset of fever. In view of case-effectiveness, additional echocardiographic studies are justified only if abnormalities are present at admission. ESR, CRP, and urinalysis performed at the 6 weeks after onset of KD is not significant for clinical information of progression. Platelet count should be estimated at 6th week for a judgement of continuous antiplatelet therapy.

Clinical Significance of C-reactive Protein in Measles (홍역 환아에서 C-반응 단백(CRP)의 의의)

  • Choi, Sang-Lim;Lee, Kyung-Yil;Lee, Hyung-Shin;Hong, Ja-Hyun;Whang, Kyung-Tai
    • Clinical and Experimental Pediatrics
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    • v.46 no.5
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    • pp.480-483
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    • 2003
  • Purpose : We evaluated clinical manifestations and laboratory findings in patients with measles according to C-reactive protein(CRP) concentration. Methods : A retrospective analysis was performed using the medical records of patients with measles at The Catholic University of Korea, Daejeon St. Mary's Hospital from October 1999 to May 2000. We divided the patients with measles into four groups according to CRP level, i.e., those with below 5 mg/L(134 patients, negative group), those with 6-19 mg/L(85 patients), those with 20-49 mg/L(27 patients), and those over 50 mg/L(7 patients). We compared clinical and laboratory characteristics among these four groups. Results : The mean CRP level of all patients was $11.1{\pm}7.5mg/L$. No statistical differences were present between the negative group and the 6-19 mg/L group or the 20-49 mg/L group in the duration of fever, hospitalization days, complications determined with longer hospitalization for more than eight days, white blood cell count, and incidence of hepatitis. Compared with the negative group, the over 50 mg/L group showed a longer duration of fever($4.7{\pm}1.7$ vs $7.2{\pm}3.9days$), duration of hospitalization($5.4{\pm}1.4$ vs $9.4{\pm}4.7days$), incidence of complications(5.2% vs 42.9%) and a higher mean level of WBC count($5,900{\pm}2,700/mm^3$ vs $12,700{\pm}6,700/mm^3$). With an increasing CRP level, there was a tendency for the duration of fever, complications and WBC count to increase. However the levels of liver enzymes(AST/ALT) were not associated with CRP level. Conclusion : A CRP level of over 50 mg/L in measles is associated with severity and complications.

The Effects of Glenohumeral Abduction Motion and Intra-articular Movement after Passive Caudal Gliding Mobilization in Frozen Shoulder Patients (상완와관절의 수동하방활주운동이 오십견환자의 외전운동과 관절 내 움직임에 미치는 영향)

  • Seo Jong-Hak;Bae Sung-Soo;Kim Chul-Yong
    • The Journal of Korean Physical Therapy
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    • v.15 no.3
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    • pp.126-152
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    • 2003
  • The purpose of this study was to evaluate the value of passive caudal gliding mobilization of the glenohumeral joint on the range of motion (ROM) of active and passive abduction; to evaluate the value of pain relief through visual analogue scale (VAS); to evaluate the correlation between improvement of shoulder abduction and intra-articular movement measured by fluoroscopy in frozen shoulder patients. The subjects consisted of twenty-one patients with clinically diagnosed frozen shoulder (11 males, 10 females) between 40 and 63 years of age (mean age : 52.7 years). The traction and caudal gliding mobilization based on the convex-concave rule in the resting position and at end range of abduction was peformed for 15 minutes per day and was repeated 10 times during a 2 week period. The ROM of abduction was measured by goniometer and pain was measured by VAS. The intra-articular movement was measured by fluoroscope, Neurostar Plus TOP (Siemens, Germany). ROM measurements of each patient was acquired at pre-treatment, immediate post-treatment and 2 week post-treatment. Statistical analysis was performed using SPSS 10.0 for Windows software and data was analyzed using the paired-test and the pearson correlation. The results of this study are as follows: 1. There was a significant decrease of VAS between pre-treatment data and 2 week post-treatment data (P<.05) but no significant difference between pre-treatment and immediate post-treatment data (P>.05). 2. There was a significant increase in ROM of active and passive abduction in the pre-treatment data, immediate post-treatment data, and in 2 week post-treatment data (P<.05). 3. With regard to results of the joint play test, there was a significant difference in the grade of traction between pre-treatment data and immediate post-treatment data and between pre-treatment data and 2 week post-treatment data (P<.05). There was no significant difference between immediate post-treatment data and 2 week post-treatment data (P>.05). 4. With regard to results of the joint play test, there was a significant difference in the grade of caudal gliding between pre-treatment data and immediate post-treatment data and between pre-treatment data and 2 week post-treatment data (P<.05). There was no significant difference between immediate post-treatment data and 2 week post-treatment data (P>.05), 5. With regard to the results of fluoroscopic findings, there was a significant change of the glenohumeral joint space between pre-treatment data and immediate post-treatment data and between immediate post-treatment data and 2 week post-treatment data (P<.05). There was no significant change of the glenohumeral joint space between immediate post-treatment data and 2 week post-treatment data (P>.05). 6. With regard to the results of fluoroscopic findings, there was a significant change of acromiohumeral joint space between the three data (pre-treatment data, immediate post-treatment data, 2 week post-treatment data) (P<.05). 7. Mobility grade by joint play test was significantly increased and was correlated to improved ROM of active and passive abduction (P<.05). In this study of frozen shoulder, passive caudal gliding techniques of the glenohumeral joint results in statistically significant changes in active and passive abduction as well as in VAS. There is also a significant correlation between joint play test and ROM of abduction.

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Functional MRI of Visual Cortex: Correlation between Photic Stimulator Size and Cortex Activation (시각피질의 기능적 MR 연구: 광자극 크기와 피질 활성화와의 관계)

  • 김경숙;이호규;최충곤;서대철
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.114-118
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    • 1997
  • Purpose: Functional MR imaging is the method of demonstrating changes in regional cerebral blood flow produced by sensory, motor, and any other tasks. Functional MR of visual cortex is performed as a patient stares a photic stimulation, so adaptable photic stimulation is necessary. The purpose of this study is to evaluate whether the size of photic stimulator can affect the degree of visual cortex activation. Materials and Methods: Functional MR imaging was performed in 5 volunteers with normal visual acuity. Photic stimulator was made by 39 light-emitting diodes on a plate, operating at 8Hz. The sizes of photic stimulator were full field, half field and focal central field. The MR imager was Siemens 1.5-T Magnetom Vision system, using standard head coil. Functional MRI utilized EPI sequence (TR/TE= 1.0/51. Omsec, matrix $No.=98{\times}128$, slice thickness=8mm) with 3sets of 6 imaging during stimulation and 6 imaging during rest, all 36 scannings were obtained. Activation images were obtained using postprocessing software(statistical analysis by Z-score), and these images were combined with T-1 weighted anatomical images. The activated signals were quantified by numbering the activated pixels, and activation a index was obtained by dividing the pixel number of each stimulator size with the sum of the pixel number of 3 study using 3 kinds of stimulators. The correlation between the activation index and the stimulator size was analysed. Results: Mean increase of signal intensities on the activation area using full field photic stimulator was about 9.6%. The activation index was greatest on full field, second on half field and smallest on focal central field in 4. The index of half field was greater than that of full field in 1. The ranges of activation index were full field 43-73%(mean 55%), half field 22-40 %(mean 32%), and focal central field 5-24%(mean 13%). Conclusion: The degree of visual cortex activation increases with the size of photic stimulator.

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Anger-coping types and hypertension in some employed men (일부 남자 고용집단에서 분노 대응형태와 고혈압)

  • Lee, Choong-Won;Park, Jong-Won;Lee, Se-Youp
    • Journal of Preventive Medicine and Public Health
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    • v.28 no.2 s.50
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    • pp.462-472
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    • 1995
  • This study examined the relation between anger-coping types and hypertension in employed men aged $40\sim60$ who consented to participate during the biannual physical checkup in the department of health management in 1988. The subjects analyzed were five hundred thirteen excluding those having hypertension history and/or current antihypertensive medications. Anger-coping types were constructed from the Harburg's model with two hypothetical anger-provoking situations involving wife and boss. Hypertensives were defined more than 140mmHg systolic blood pressure and/or 90mmHg diastolic blood pressure. Hypertensives were one hundred fifty two(29.6%) and those who suppressed their anger were 61.6% and 62.8% in wife and boss situations respectively. Items of anger, guilt, protest, and suppressed anger in wife situation showed odds ratios of 0.78-0.94 without statistical significance. But four items in boss situation showed odds ratios more than 1, especially anger-in types of anger item had 1.58 times the prevalence of hypertension of anger-out types(95% confidence intervals(CI) $1.06\sim2.35$) and subjects who indicated that suppressed their anger had 1.55 times the prevalence of hypertension of those who expressed their anger(95% CI $1.03\sim2.32$). For anger suppressed vs. expressed types of total suppressed anger index, prevalence of hypertension was 1.31 (95% CI $0.83\sim2.08$). After adjusting for age, body mass index, smoking and drinking, the odds ratios were slightly increased in both situations except guilt items compared with univariate analysis. These results suggest that the relation between Harburg's anger-coping model and hypertension is replicated partially in this subjects.

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