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The Palliative Radiation Therapy in Malignant Extra-Hepatic Biliary Obstruction (간외 폐쇄성 황달 환자에서 고식적 방사선치료의 결과)

  • Kay Chul-Seoung;Jang Hong-Suk;Kim Sung-hwan;Ryu Mi-Ryeong;Kim Yeon-Shil;Chung Su-Mi;Yoon Sei-Chul
    • Radiation Oncology Journal
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    • v.17 no.3
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    • pp.209-216
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    • 1999
  • Purpose : To evaluate the effectiveness of external radiation therapy and the prognostic factors, we retrospectively analyzed therapeutic results of malignant extrahepatic biliary obstruction (EHBO). Methods and Materials : We analyzed the results of the external radiation therapy in 59 patients of inoperable malignant EHBO who had been treated with more than 10 Gy of external radiation therapy from April 1984 to December 1990. There were 21 stomach cancer ($35.6\%$), 12 pancreas cancer ($20.3\%$), 15 extrahepatic biliary cancer ($18.0\%$) and 11 another cancer ($18.0\%$). Their pathologies were confirmed in 31 patients ($52.5\%$). They divided into 27 adenocarcinoma and 4 nonadenocarcinoma. Their chief complaints were jaundice in 47 patients ($79.7\%$) and abdominal pain in 15 patients ($49.2\%$). Twelve patients had slightly increased bilirubin level in liver function test without jaundice. We treated twenty four patients ($40.6\%$) with percutaneous transhepatic biliary drainage (PTBD) and 32 patients ($54\%$) with systemic chemotherapy (CT). We performed external radiation therapy (ERT) upto $10.8\~55.8$ Gy (median 37.8 Gy) with palliative aim. Results : Overall median survival duration was $7.80\pm1.15$ months. The response rates of jaundice were $81.8\%$ in PTBO group and $66.7\%$ in non-PTBD group without statistical significance. The improving rate of jaundice was not significantly different in decreased ratio of total bilirubin level. But abdominal pain was more decreased in CT group than non-CT group (p<0.05). The significant prognostic factors were high performance status (Karnofski Performance Status >70), total radiation dose more than 35 Gy and good response of pain after therapy. There were increased in bacterial cholagitis in PTBD group and gastrointestinal complications in CT group. Conclusion : External radiotheapy could improve jaundice and abdominal pain in malignant EHBO patients, Overall survival duration was prolonged in patients with higher performance status and patients who had been treated with more than 35 Gy of total radiation dose. In the future, we expect not only better palliative role but also the prolongation of survival of using the ERT combined with other treatment method. But to achieve certain conclusion, we need luther study consisted with many kinds of treatment methods including new technologies in RT.

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Effect of the Level of Concentrates and Pasture Grazing on Growth, Reproductive Performance and Feed Efficiency in Spring born Hanwoo Heifers (농후사료 급여수준 및 방목이 춘계분만 한우 암송아지의 성장발육, 번식능력 및 사료이용성에 미치는 효과)

  • Kang, S. W.;Im, S. K.;Jeong, J. W.;Woo, J. S.;Jeon, K. J.
    • Journal of Animal Science and Technology
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    • v.45 no.1
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    • pp.101-112
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    • 2003
  • This study was conducted to investigate the effect of the level of concentrates and pasture grazing in 60 head of spring born Hanwoo heifers(initial body weight; 125.3kg) for 450days from six to 21 months in age. Feeding trial was conducted with 5 treatment(twelve heads/ treatment) which were T1(1.5% of apparent body weight in concentrates and indoor feeding for over-all period), T2(0.5% of apparent body weight in concentrates for pre-pasture grazing and pasture grazing), T3(1.0% of apparent body weight in concentrates for pre-pasture grazing and pasture grazing), T4(1.5% of apparent body weight in concentrates for pre-pasture grazing and pasture grazing), T5(2.0% of apparent body weight in concentrates for pre-pasture grazing and pasture grazing). During the total experimental period, average daily gains by treatments ranged from 0.322 to 0.465kg(average 0.405kg) and higher in the order of T5, T4, T1, T3 and T2, and increased with the level of concentrates feeding for pre-pasture grazing. TDN intakes required per unit of kilogram gain were 9.13 to 9.79kg(average 9.49kg) higher in the order of T1, T3, T5, T4 and T2, For the grazing period, they were ranged from 12.39 to 12.98kg(average 12.68kg), and were not significantly different. But TDN requirements of grazing groups was higher about 15.6% than the indoor feeding group’s. The rate of roughage to concentrates by treatments were 57.8 to 73.6%(average 63.7%). The body weight of 15 and 21 month in ages, that is, the ages at puberty and first conception by treatments were 201.2 to 230.7kg(average 223.8kg) and 270.2 to 331.4kg (average 307.6kg), respectively, and the latter were high per unit of 20.4kg by increasing the level of concentrates feeding for pre-pasture grazing every 0.5% addition of apparent body weight. The age of 225 and 275kg in body weight, that is, the body weight at puberty and first conception by treatments were 14.0 to 17.6 month (average 15.3 month) and 17.9 to 21.7 month(average 19.4), respectively, and the latter were shorter about 1.3 month by increasing the level of concentrates feeding every 0.5% addition of apparent body weight. According to the above results, it may be concluded that spring born Hanwoo heifers are raised at indoor have to feed with 1.8% of body weight in concentrates under full feeding of rice straws for all period from six to 21 months in age, but with 1.5% of apparent body weight in concentrates for grazing period.

Clinical Assessment and Cephalometric Characteristics in Patients with Condylar Resorption (하악과두흡수 환자의 임상적 평가 및 악안면 골격형태에 대한 연구)

  • Koo, Seon-Ju;Kim, Kyun-Yo;Hur, Yun-Kyung;Chae, Jong-Moon;Choi, Jae-Kap
    • Journal of Oral Medicine and Pain
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    • v.34 no.1
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    • pp.91-102
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    • 2009
  • Condylar resorption, or condylysis can be defined as progressive alteration of condylar shape and decrease in mass. Condylar resorption is a poorly understood progressive disease that affects the TMJ and that can result in malocclusion, facial disfigurement, TMJ dysfunction, and pain. The aim of this study was to investigate clinical assessment and cephalometric characteristics in 224 patients with condylar resorption, who visited in the Department of Oral Medicine Kyungpook National University Hospital at 2006, by use of panorama, transcranial view and lateral cephalometric radiograph. The results were as follows; 1. Clinical assessment 1) Total number of patients who visited with chief complaints of TMD were 2419 and 224 (9.3%) among them revealed the condylar resorption, Among patients group with condylar resorption, female was 183 and male was 41, females were predominant. 2) Patient's age ranged from 12 to 70 and mean age was 30.6 years old with a strong predominance for 10s and 20s. Distribution of a showed as follows; 10s was 26.3%, 20s was 34,8%, 30s was 13.8%, 40s was 11.2%, 50s was 7.1%, 60s was 6.3% and 70s was 0.4%. 3) Most of the patients had parafunctional habit. 4) The case of showing the pain in condylar resorption was 145, the case of not showing the pain was 79. 5) Treatment duration of the patients was relatively short. 2. Cephalometric Characteristics 1) ANB which means the retruding of the mandible increased significantly than normal group. The ANB of female was lager than male group as the means of ANB were 5.05 in female and 3.57 in male, 2) SN-GoMe and FMA increased in resorption patients, but FH-PP did not show any significant difference. The FMA of female was lager than male group as the means were 31.69 in female and 30.44 in male. 3) Total posterior facial height was significantly smaller and total anterior facial height showed no significant increase as compared with those of the normal group. Condylar resorption was predominant in young female which was caused by more vertical facial pattern in female than male and increase of parafunctional habit in young age. It was thought that the patients who have a risk factor increasing the compressive stress at condyle caused by obliquely inclined masseter and medial pterygoid show high prevalence of condylar resorption.

A Study on the Traumatic Teeth Damage of Children (어린이의 외상성 치아손상에 관한 연구)

  • Yoo, Su-Min;Park, Ho-won
    • Journal of dental hygiene science
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    • v.4 no.1
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    • pp.21-25
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    • 2004
  • In modern times, children's trauma is increasing every year because of car accidents and life environment changes. There is a limit to prevent traumatic damage for oral cavity organization. The fundamental data of trauma treatment and prevention will be presented through the survey and analysis of traumatic teeth damage. I examined 113 patients from Oct. 4th, 2000 to Feb. 27th, 2004 at Dept. of Children's Dental Clinic, Kangnung National University. The results are as follows. (1) The trauma frequency of male subjects is higher than that of female at a rate of 2.05:1. The average age is 5.27 for men and 5.27 for women. The highest percentage of trauma patients is among 2 year old children. It is 21.2%. (2) A patient survey was taken at a trauma treatment hospital. On the first day 34.4% of the patients had come to receive treatment of their first set of teeth. However, after a week, 38.8% of the patients had received treatment on their permanent teeth. (3) As a result of falling, 59% of patients needing treatment on their first set of teeth. 55.1% of patients is permanent teeth. As a result of bump against physical solid, 26.6% of patients is the first set of teeth and 26.5% of patients is permanent teeth. (4) Teeth damage happened at home. 42.1% were male. 35.1% were female. According to trauma, 59.4% of teeth damage happened at home. 28.6% of permanent teeth damage happened at school or kindergarten. (5) According to trauma, the number of teeth damaged was in the first set of teeth are as follows: 56.3%, one-31.3%, three or four-6.3% each. For permanent teeth: two-46.9%, one-28.6%, four over-16.3% and three-8.2%. Over four teeth is larger number for permanent teeth. (6) 56% of first set of teeth patients and 43.4% of permanent teeth patients were male. 56.8% of first set of teeth patients and 43.2% of permanent teeth were female. Trauma happened to both male and female frequently in the first set of teeth. (7) Most of the tooth damage which was in the first set of teeth and permanent teeth was done to the upper jaw. 75% of patients are the first set of teeth. 63.8% of patients are permanent teeth. Trauma is very high in the two mid teeth of the upper jaw. (8) According to trauma survey, 30.2% is from impulse. 28.0% is from crown fracture, 14.7% is from depression. 8.9% is from concussion. 7.1% is from full dislocation of a joint. 2.2% of patients are extrusion. 1.8% is from displacement. According to teeth damage trauma, 35.8% is pulse in the first set of teeth. The breaking of the crown of a tooth happened a lot in permanent teeth. (9) According to data, 43.2% of teeth damage in the first set of teeth goes without treatment. In permanent teeth, it is 38.9%. After treatment, 22.0% of first set of teeth treatment requires a dental pulp treatment. In permanent teeth, which is used for temporary acid etching resin restoration.

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The Impact of Bladder Volume on Acute Urinary Toxicity during Radiation Therapy for Prostate Cancer (전립선암의 방사선치료시 방광 부피가 비뇨기계 부작용에 미치는 영향)

  • Lee, Ji-Hae;Suh, Hyun-Suk;Lee, Kyung-Ja;Lee, Re-Na;Kim, Myung-Soo
    • Radiation Oncology Journal
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    • v.26 no.4
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    • pp.237-246
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    • 2008
  • Purpose: Three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) were found to reduce the incidence of acute and late rectal toxicity compared with conventional radiation therapy (RT), although acute and late urinary toxicities were not reduced significantly. Acute urinary toxicity, even at a low-grade, not only has an impact on a patient's quality of life, but also can be used as a predictor for chronic urinary toxicity. With bladder filling, part of the bladder moves away from the radiation field, resulting in a small irradiated bladder volume; hence, urinary toxicity can be decreased. The purpose of this study is to evaluate the impact of bladder volume on acute urinary toxicity during RT in patients with prostate cancer. Materials and Methods: Forty two patients diagnosed with prostate cancer were treated by 3DCRT and of these, 21 patients made up a control group treated without any instruction to control the bladder volume. The remaining 21 patients in the experimental group were treated with a full bladder after drinking 450 mL of water an hour before treatment. We measured the bladder volume by CT and ultrasound at simulation to validate the accuracy of ultrasound. During the treatment period, we measured bladder volume weekly by ultrasound, for the experimental group, to evaluate the variation of the bladder volume. Results: A significant correlation between the bladder volume measured by CT and ultrasound was observed. The bladder volume in the experimental group varied with each patient despite drinking the same amount of water. Although weekly variations of the bladder volume were very high, larger initial CT volumes were associated with larger mean weekly bladder volumes. The mean bladder volume was $299{\pm}155\;mL$ in the experimental group, as opposed to $187{\pm}155\;mL$ in the control group. Patients in experimental group experienced less acute urinary toxicities than in control group, but the difference was not statistically significant. A trend of reduced toxicity was observed with the increase of CT bladder volume. In patients with bladder volumes greater than 150 mL at simulation, toxicity rates of all grades were significantly lower than in patients with bladder volume less than 150 mL. Also, patients with a mean bladder volume larger than 100 mL during treatment showed a slightly reduced Grade 1 urinary toxicity rate compared to patients with a mean bladder volume smaller than 100 mL. Conclusion: Despite the large variability in bladder volume during the treatment period, treating patients with a full bladder reduced acute urinary toxicities in patients with prostate cancer. We recommend that patients with prostate cancer undergo treatment with a full bladder.

A Study on the Investigation of Sanitary Knowledge and Practice Level of School Foodservice Employees in Jeonju (전주지역 학교급식 조리종사자의 위생지식 및 위생관리 수행에 관한 연구)

  • Han, Eun-Hui;Yang, Hyang-Sook;Shon, Hee-Sook;Rho, Jeong-Ok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.8
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    • pp.1210-1218
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    • 2005
  • This study was to investigate the sanitary knowledge and its practice level of school foodservice employees in Jeonju area. A total of 508 questionnaires were usable; resulting in 79.0$\%$ response rate. Statistics data analysis was completed using the SPSS 10.0 program. The results of this study were summarized as follow : About 62$\%$ of school foodservice employees were 41 $\∼$50 years old and 84$\%$ of them had a irregular job and they had a sanitation training at least once a month. The school foodservice employees had more knowledge about 'personal hygiene' than that about 'equipment and facilities sanitation', 'foodborn disease and food microorganism' Their hygiene practice level were high for 'equipment and facilities sanitation' (4.90$\pm$0.25) and were lesser in the order from 'foodborn disease and food microorganism'(4.86$\pm$0.30), 'personal sanitation'(4.79$\pm$0.34) and the least for food processing hygiene (4.70$\pm$0.37). As a result of relationship between knowledge and hygiene practice level, knowledge of school foodservice employees was not influenced on tile hygiene practice level during their working.

Clinical Study of Pulmonary Tuberculosis for Admitted Patients at National Masan Tuberculosis Hospital (국립마산결핵병원에 입원한 환자에 대한 폐결핵의 임상적 동태에 관한 연구)

  • Park, Seung-Kyu;Choi, In-Hwan;Kim, Chul-Min;Kim, Cheon-Tae;Song, Sun-Dae
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.2
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    • pp.241-250
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    • 1997
  • Objective : Although the prevalence of pulmonary tuberculosis has decreased progressively after the national control program for tuberculosis began, nowadays the number of MDRTB is increasing seriously. MDRTB tends to be poor responsive to current antituberculosis regimens. It is mainly due to poor compliance, high rate of side reaction of secondary drugs, and limitation in number of available drugs. The purpose of present study is to evaluate the clinical features of pulmonary tuberculosis patients admitted in one national tuberculosis hospital and to expose the problems pertaining to current remedies, to increase the treatment efficacy for pulmonary tuberculosis including MDRTB in the end. Method : Retrospective analysis of 336 pulmonary tuberculosis patients admitted in National Masan Tuberculosis Hospital was done. Contents of analysis were patients profile, the first diagnosed time and medical institutes, family history, residence, previous treatment history, chief complaints at the time of admission, lesion site on chest X -ray film, combined deseases, side reaction to antibuberculosis drugs, used drugs before admission and the results of drug sensitivity test. Results : The ratio between male and female was 4 : 1. Age showed relatively even distribution from 3rd to 6 th decades. 64.6% of the patients was diagnosed at public health center. Weight loss was the most common complaint at admission. Bilateral lesions on chest X-ray films were 59.8%. 130patients had combined desease, of which DM was the most common(37.7%). 95patients had family history, of which parents were the most common(41.7%). According to the time of first diagnosis, 31 patients were diagnosed before 1980, and after then the number of patients was increased by degrees. Residence overwhelmed in pusan and gyung-nam province. 258 patients got previous treatment history, of which 112 patients(43.4%) had more than 3 times and only 133 patients(51.6%)got regular medication. 97 patients used more than other 3 drugs in addition to INH, EMB, RFP and PZA before admission. 154 patients were informed with the results of drug sensitivity test. of which 77 patients had resistance to more than 5 drugs. Gastrointestinal problem was the most common in side reaction to drugs. Conclusion : In the case of weight loss of unknown cause, tuberculosis should be suspected. In first treatment, sufficient and satisfactory explanation for tuberculosis is necessary and treatment period should not be stict to 6 month-short term therapy. In retreatment, new drugs should not be added to used drugs even though drug sensitivity results show sensitivity to some of them. Proper time for surgical intervention should not be delayed.

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The Influence of Obstructive Sleep Apnea on Systemic Blood Pressure, Cardiac Rhythm and the Changes of Urinary (폐쇄성 수면 무호흡이 전신성 혈압, 심조율 및 요 Catecholamines 농도 변화에 미치는 영향)

  • Lo, Dae-Keun;Choi, Young-Mee;Song, Jeong-Sup;Park, Sung-Hak;Moon, Hwa-Sik
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.1
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    • pp.153-168
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    • 1998
  • Background: The existing data indicate that obstructive sleep apnea syndrome contributes to the development of cardiovascular dysfunction such as systemic hypertension and cardiac arrhythmias, and the cardiovascular dysfunction has a major effect on high long-term mortality rate in obstructive sleep apnea syndrome patients. To a large extent the various studies have helped to clarify the pathophysiology of obstructive sleep apnea, but many basic questions still remain unanswered. Methods: In this study, the influence of obstructive sleep apnea on systemic blood pressure, cardiac rhythm and urinary catecholamines concentration was evaluated. Over-night polysomnography, 24-hour ambulatory blood pressure and ECG monitoring, and measurement of urinary catecholamines, norepinephrine (UNE) and epinephrine (UEP), during waking and sleep were undertaken in obstructive sleep apnea syndrome patients group (OSAS, n=29) and control group (Control, n=25). Results: 1) In OSAS and Control, UNE and UEP concentrations during sleep were significantly lower than during waking (P<0.01). In UNE concentrations during sleep, OSAS showed higher levels compare to Control (P<0.05). 2) In OSAS, there was a increasing tendency of the number of non-dipper of nocturnal blood pressure compare to Control (P=0.089). 3) In both group (n=54), mean systolic blood pressure during waking and sleep showed significant correlation with polysomnographic data including apnea index (AI), apnea-hypopnea index (AHI), arterial oxygen saturation nadir ($SaO_2$ nadir) and degree of oxygen desaturation (DOD). And UNE concentrations during sleep were correlated with AI, AHI, $SaO_2$ nadir, DOD and mean diastolic blood pressure during sleep. 4) In OSAS with AI>20 (n==14), there was a significant difference of heart rates before, during and after apneic events (P<0.01), and these changes of heart rates were correlated with the duration of apnea (P<0.01). The difference of heart rates between apneic and postapneic period (${\Delta}HR$) was significantly correlated with the difference of arterial oxygen saturation between before and after apneic event (${\Delta}SaO_2$) (r=0.223, P<0.001). 5) There was no significant difference in the incidence of cardiac arrhythmias between OSAS and Control In Control, the incidence of ventricular ectopy during sleep was significantly lower than during waking. But in OSAS, there was no difference between during waking and sleep. Conclusion : These results suggested that recurrent hypoxia and arousals from sleep in patients with obstructive sleep apnea syndrome may increase sympathetic nervous system activity, and recurrent hypoxia and increased sympathetic nervous system activity could contribute to the development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac function.

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The Prognostic Value of the First Day and Daily Updated Scores of the APACHE III System in Sepsis (패혈증환자에서 APACHE III Scoring System의 예후적 가치)

  • Lim, Chae-Man;Lee, Jae-Kyun;Lee, Sung-Soon;Koh, Youn-Suck;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong;Park, Pyung-Hwan;Choi, Jong-Moo
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.6
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    • pp.871-877
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    • 1995
  • Background: The index which could predict the prognosis of critically ill patients is needed to find out high risk patients and to individualize their treatment. The APACHE III scoring system was established in 1991, but there has been only a few studies concerning its prognostic value. We wanted to know whether the APACHE III scores have prognostic value in discriminating survivors from nonsurvivors in sepsis. Methods: In 48 patients meeting the Bones criteria for sepsis, we retrospectively surveyed the day 1(D1), day 2(D2) and day 3(D3) scores of patients who were admitted to intensive care unit. The scores of the sepsis survivors and nonsurvivors were compared in respect to the D1 score, and also in respect to the changes of the updated D2 and D3 scores. Results: 1) Of the 48 sepsis patients, 21(43.5%) survived and 27(56.5%) died. The nonsurvivors were older($62.7{\pm}12.6$ vs $51.1{\pm}18.1$ yrs), presented with lower mean arterial pressure($56.9{\pm}26.2$ vs $67.7{\pm}14.2\;mmHg$) and showed greater number of multisystem organ failure($1.2{\pm}0.8$ vs $0.2{\pm}0.4$) than the survivors(p<0.05, respectively). There were no significant differences in sex and initial body temperature between the two groups. 2) The D1 score was lower in the survivors (n=21) than in the nonsurvivors ($44.1{\pm}14.6$, $78.5{\pm}18.6$, p=0.0001). The D2 and D3 scores significantly decreased in the survivors (D1 vs D2, $44.1{\pm}14.6$ : $37.9{\pm}15.0$, p=0.035; D2 vs D3, $37.9{\pm}15.0$ : $30.1{\pm}9.3$, p=0.0001) but showed a tendency to increase in the nonsurvivors (D1 vs D2 (n=21), $78.5{\pm}18.6$ : $81.3{\pm}23.0$, p=0.1337; D2 vs D3 (n=11), $68.2{\pm}19.3$ : $75.3{\pm}18.8$, p=0.0078). 3) The D1 scores of 12 survivors and 6 nonsurvivors were in the same range of 42~67 (mean D1 score, $53.8{\pm}10.0$ in the survivors, $55.3{\pm}10.3$ in the nonsurvivors). The age, sex, initial body temperature, and mean arterial pressure were not different between the two groups. In this group, however, D2 and D3 was significantly decreased in the survivors(D1 vs D2, $53.3{\pm}10.0$ : $43.6{\pm}16.4$, p=0.0278; D2 vs D3, $43.6{\pm}16.4$ : $31.2{\pm}10.3$, p=0.0005), but showed a tendency to increase in the nonsurvivors(D1 vs D2 (n=6), $55.3{\pm}10.3:66.7{\pm}13.9$, p=0.1562; D2 vs D3 (n=4), $64.0{\pm}16.4:74.3{\pm}18.6$, p=0.1250). Among the individual items of the first day APACHE III score, only the score of respiratory rate was capable of discriminating the nonsurvivors from the survivors ($5.5{\pm}2.9$ vs $1.9{\pm}3.7$, p=0.046) in this group. Conclusion: In sepsis, nonsurvivors had higher first day APACHE III score and their updated scores on the following days failed to decline but showed a tendency to increase. Survivors, on the other hand, had lower first day score and showed decline in the updated APACHE scores. These results suggest that the first day and daily updated APACHE III scores are useful in predicting the outcome and assessing the response to management in patients with sepsis.

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Memory Organization for a Fuzzy Controller.

  • Jee, K.D.S.;Poluzzi, R.;Russo, B.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1041-1043
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    • 1993
  • Fuzzy logic based Control Theory has gained much interest in the industrial world, thanks to its ability to formalize and solve in a very natural way many problems that are very difficult to quantify at an analytical level. This paper shows a solution for treating membership function inside hardware circuits. The proposed hardware structure optimizes the memoried size by using particular form of the vectorial representation. The process of memorizing fuzzy sets, i.e. their membership function, has always been one of the more problematic issues for the hardware implementation, due to the quite large memory space that is needed. To simplify such an implementation, it is commonly [1,2,8,9,10,11] used to limit the membership functions either to those having triangular or trapezoidal shape, or pre-definite shape. These kinds of functions are able to cover a large spectrum of applications with a limited usage of memory, since they can be memorized by specifying very few parameters ( ight, base, critical points, etc.). This however results in a loss of computational power due to computation on the medium points. A solution to this problem is obtained by discretizing the universe of discourse U, i.e. by fixing a finite number of points and memorizing the value of the membership functions on such points [3,10,14,15]. Such a solution provides a satisfying computational speed, a very high precision of definitions and gives the users the opportunity to choose membership functions of any shape. However, a significant memory waste can as well be registered. It is indeed possible that for each of the given fuzzy sets many elements of the universe of discourse have a membership value equal to zero. It has also been noticed that almost in all cases common points among fuzzy sets, i.e. points with non null membership values are very few. More specifically, in many applications, for each element u of U, there exists at most three fuzzy sets for which the membership value is ot null [3,5,6,7,12,13]. Our proposal is based on such hypotheses. Moreover, we use a technique that even though it does not restrict the shapes of membership functions, it reduces strongly the computational time for the membership values and optimizes the function memorization. In figure 1 it is represented a term set whose characteristics are common for fuzzy controllers and to which we will refer in the following. The above term set has a universe of discourse with 128 elements (so to have a good resolution), 8 fuzzy sets that describe the term set, 32 levels of discretization for the membership values. Clearly, the number of bits necessary for the given specifications are 5 for 32 truth levels, 3 for 8 membership functions and 7 for 128 levels of resolution. The memory depth is given by the dimension of the universe of the discourse (128 in our case) and it will be represented by the memory rows. The length of a world of memory is defined by: Length = nem (dm(m)+dm(fm) Where: fm is the maximum number of non null values in every element of the universe of the discourse, dm(m) is the dimension of the values of the membership function m, dm(fm) is the dimension of the word to represent the index of the highest membership function. In our case then Length=24. The memory dimension is therefore 128*24 bits. If we had chosen to memorize all values of the membership functions we would have needed to memorize on each memory row the membership value of each element. Fuzzy sets word dimension is 8*5 bits. Therefore, the dimension of the memory would have been 128*40 bits. Coherently with our hypothesis, in fig. 1 each element of universe of the discourse has a non null membership value on at most three fuzzy sets. Focusing on the elements 32,64,96 of the universe of discourse, they will be memorized as follows: The computation of the rule weights is done by comparing those bits that represent the index of the membership function, with the word of the program memor . The output bus of the Program Memory (μCOD), is given as input a comparator (Combinatory Net). If the index is equal to the bus value then one of the non null weight derives from the rule and it is produced as output, otherwise the output is zero (fig. 2). It is clear, that the memory dimension of the antecedent is in this way reduced since only non null values are memorized. Moreover, the time performance of the system is equivalent to the performance of a system using vectorial memorization of all weights. The dimensioning of the word is influenced by some parameters of the input variable. The most important parameter is the maximum number membership functions (nfm) having a non null value in each element of the universe of discourse. From our study in the field of fuzzy system, we see that typically nfm 3 and there are at most 16 membership function. At any rate, such a value can be increased up to the physical dimensional limit of the antecedent memory. A less important role n the optimization process of the word dimension is played by the number of membership functions defined for each linguistic term. The table below shows the request word dimension as a function of such parameters and compares our proposed method with the method of vectorial memorization[10]. Summing up, the characteristics of our method are: Users are not restricted to membership functions with specific shapes. The number of the fuzzy sets and the resolution of the vertical axis have a very small influence in increasing memory space. Weight computations are done by combinatorial network and therefore the time performance of the system is equivalent to the one of the vectorial method. The number of non null membership values on any element of the universe of discourse is limited. Such a constraint is usually non very restrictive since many controllers obtain a good precision with only three non null weights. The method here briefly described has been adopted by our group in the design of an optimized version of the coprocessor described in [10].

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