무선 ATM망에서의 동적 대역폭 할당 알고리즘에 대한 QoS 성능 연구

류기훈,김지연,전광탁,양해권 군산대학교 정보통신기술연구소 2000 情報通信技術硏究論文集 Vol.4 No.-

In the network with small cell radius, a mobile terminal which has large mobility should perform frequent handover. This requires that handover mechanism must be done fastly. As cell size is smaller, signal power level is lower Handover is implemented by the network to give the users freedom of motion beyond a limited wireless coverage area while they are communication. The handover is procedure by which a user's radio link is transferred from one radio port to another through the network without an interruption of the user collection. The currently existing method for handover uses an algorithm, in which the bandwidth corresponding to the adjacent cells is supposed to be allocated. However, this method leads to the problem of requiring bandwidth allocation for many-unknown cells, due to the lack of information toward moving direction in mobile terminal. In this paper, we propose an efficient dynamic bandwidth allocation algorithm for solving those problem above, based on both path rerouting handover and soft hangover mechanism with wireless ATM. Thus, only the bandwidth for corresponding adjacent cell, that is from estimation, is chosen to be reserved; this method drastically reduces the waste of bandwidth, and improves the efficiency in performance. Comparing with static bandwidth allocation algorithm, the proposed algorithm make a bandwidth allocation more efficient. As for the QoS, it has been shown that proposed algorithm shows better performance than that with static bandwidth allocation algorithm.

혈액투석중인 말기신부전 환자에서 Fludrocortisone acetate (FCA) 투여 후 혈청 칼륨 저하 효과

류봉관,강대웅,정지용,윤나라,신병철,박경희,정종훈,김현리 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.1

Background: Hyperkalemia is a commonly encountered problem in dialysis patients with end-stage renal disease. In this study we evaluated the effect of mineralocorticoid therapy (fludrocortisono acetate) on serum potassium level in the serum of hyperkalemic end-stage renal disease patients. Methods: Fourteen patients on hemodialysis receiving fludrocortisone acetate (FCA) 0.1 mg/day were observed for 2 months periods. Consecutive monthly biochemical profiles were compared for the druration of the pre-and post-treatment of FCA. Result: Fourteen patients with mean age (±SE) of 51.5 years (4 males and 10 females) and mean hemodialysis period of 51.9 months were studied. Mean serum potassium levels significantly fell (p<0.05) during the post-FCA period (5.2±0.66 mEq/L) compared with potassium levels during the pre-FCA (5.8±0.43 mEq/L) period. Pre-and post-FCA values were not different for sodium, chloride, protein, albumin, AST/ALT, glucose, blood nitrogen, creatinine, phosphate and calcium. Conclusions: FCA appears to decrease serum potassium value in patients with end-stage renal disease. These results suggested that FCA could be effective to treat hyperkalemia without any adverse effect in patients undergoing hemodialysis.

F.D.M.을 應用한 1次元 壓密解析의 最適法 糾明

김지호,류권일,고영헌,김팔규 忠南大學校 産業技術硏究所 2001 산업기술연구논문집 Vol.16 No.2

In general, the term soft ground includes clayey soils, which have large compressibility and small shear resistance due to the external load. All process of consolidation in compressible soils can be explained in terms of transfer of load from an incompressible pore-water to a compressible soil structure. Therefore, one of the most important subjects about the characteristics of the time-dependant consolidation of the clay foundation by the charge of load may be the presumption of the final settlement caused by consolidation and the degree of consolidation according to the time. Pioneering work by Terzaghi imparted scientific and mathematical bases to many aspects of this subject and many people have used this theory to measure the consolidation settlement until now. In the paper, Finite Difference Methods for consolidation are considered. First, it is shown the stability criterion of Explicit scheme and the Crank-Nicolson scheme, although unconditionally stable in the mathematical sense, produces physically unrealistic solutions when the time step is large, it is also shown that The fully Implicit scheme shows more satisfactory behavior, but is less accurate for small time steps. And then we need to decide what scheme is more proper to consolidation. The purpose of this paper is to suggest the pertinent scheme to consolidation.

가토 대퇴정맥에서 헤파린 국소 적용과 혈관냉동이 미세혈관문합부 혈전 형성에 미치는 영향

김지영,오희균,유선열,김선헌 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.2

The effect of topical heparin application and vascular freezing on thrombosis was evaluated in the femoral vein of rabbits. The femoral veins were crushed, incised transverersely and treated by 4 different ways; 1) group 1, heparin treated only, 2) group 2, frozen only, 3) group 3, heparin treated and frozen,4) group 4, treated with saline as control. The patency was evaluated by empty-and-refill test and thrombus formation was judged by stereoscopic and SEM observation. The results obtained were as follows : 1.Thirty minutes after suture, the patency was more improved in the three groups than the control, but there was no significant difference among groups. 2.Three days after suture, the patency was more improved in the three groups than the control, and was prominent in group 1 and group 3 (P<0.05). 3.Significantly reduced thrombus could be seen in most case of group 3. These results suggest that topical application of heparin and vascular freezing is effective in

자발성 심막기종 1례

안지영,이상래,안성훈,류석용,김홍용 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Pneumopericardium, as a form of barotrauma, refers to the presence of air within the pericardial sac. The causes of pneumopericardium are various, Clinically, pneumopericardium is typically present with dyspnea and precordial chest pain. On physical examination, heart sounds are usually distant, and precordial tympany may be elicited. The diagnosis can be made by clinical and radiographic findings. Management of pneumopericardium depends on many factors, such as the age of the patient, the suspected causes, and the extent of clinically observed respiratory compromise. The case shown here, a patient who developed pneumopericardium, involved an associated underlying pulmonary parenchymal process as the cause of pneumopericardium.

고삼투압성 비케톤성 상태의 예후인자

안성훈,김양원,김미란,진헌철,안지영,이상래,류석용,김홍용,김성준,이병권,김경환 대한응급의학회 2001 대한응급의학회지 Vol.12 No.2

Background: A hyperosmolar nonketotic state has been known to have a high mortality, and even now, despite this high mortality, only a few studies of this disease have been performed. We studied the prognostic factors for the hyperosmolar nonketotic state. Methods: We retrospectively studied the cases of 40 patients who were in a hypersomolar nonketotic state when admitted to Sanggye Paik Hospital during the 6-year Period from 1995 through 2000. We divided the hyperosmolar nonketotic patients into two groups, the complete recovery group and the incomplete recovery group, and compared the clinical features, the laboratory findings, and the precipitating factors between two groups. Results: 1) A total of 40 patients were studied: 24 in the complete recovery group and 16 patients in the incomplete recovery group. The mortality rate was 32.5%. 2) No significant statistical difference existed among the clinical features of the two groups, except for the sex(p<0.01). 3) Among the laboratory findings of both groups, analysis revealed that the effective osmolarity was significantly higher among those in the incomplete recovery group(p<0.01). Serum sodium concentration was also significantly higher among those in the incomplete recovery group(p<0.01). Serum creatinine was also significantly higher among those in the incomplete recovery group(p<0.05). Serum bicarbonate concentration, on the other hand, was significantly lower among those in that group(p<0.05).4) Infection was identified as the most common precipitating factor(62.5%). Among the precipitating factors of the two groups, there were significant statistical difference in pneumonia, UTI, and inappropriate glucose control. 5) A significant statistical difference existed among the initial level of consciousness of both groups(p<0.05). 6) The only significant independent factor responsible for prognosis of nonketotic hyperosmolar state patients was the sex. Conclusion: The sex was only significant independent prognostic factor of nonketotic hyperosmolar state patients.

유지 투석중인 만성 신부전환자에서 허혈성 심질환의진단 지표로서의 심장트로닌-I의 유용성

신병철,강대웅,정지용,류봉관,서영욱,김정인,김범윤,김현리,정종훈 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.1

Background : Coronary disease is highly prevalent in patient with end stage renal disease (ESRD) and account for much of their observed morbidity and mortality. Troponin-I consistently maintains a high sensitivity and specificity and is most sensitive marker for ischemic heart disease (IHD). Method : We examed 49 hernodialyzed patients (22 male, 27 female) without evidence of acute coronary syndrome (ACS) for 6 months. Biochemical markers were measured in serial predialysis blood samples. For analysis, we used two cardio-specific assays for troponin-T (cTnT) as well as for troponin-I (cTnI) and compared the results with CK-MB (reference value ≤ 4.0 ng/mL) concentration. Results : Myocardial ischemia was observed in 47% (23/49) of patients. cTnT level above 0.1 ng/mL. and cTnI level above 0.5 ng/mL, were observed in 22% (11/49) and 20% (10/49) of patients respectively. cTnI revealed significantly higher positive rate in patients with myocardial ischemia than the patients without myocardial ischemia (43 % vs 30%) (p<0.05). cTnT and CK-MB revealed no difference in positive rate between the patients with and without myocardial ischemia (cTnT : 30% vs 15% and CK-MB : 30% vs 19%). The sensitivity and specificity of cTnI to myocardial ischemia were higher than those of cTnT and CK-MB (sensitivity 43% vs 30% and 30%. specificity 100% vs 85% and 81%). Conclusion: Both cTnT and cTnI are useful in ruling out myocardial injury in chronic renal failure patients. But. cTnI is a more sensitivity and excellent specificity of ischemic heart disease than cTnT and CK-MB in hemodialyzed patients. In patients with ischemic heart disease, the presences of DM and advanced age were higher than those in patients without ischemic heart disease (p<0.05). Among the baseline characteristics old age, elevated LDH and diabeties were significant more frequent in the patients with elevation of cardiac troponin-I (p>0.5 ng/mL) than those with cardiac troponin-I (p<0.5 ng/mL), p=0.038, p=0.049, and p=0.045, respectively. Our results suggest that these cTnI is the potential diagnostic marker for the prediction of IHD in ESRD patients.

생리식염수 및 포도당수액 정액 투여가 에탄올 농도에 미치는 효과에 관한 연구

김원율,이상래,안지영,안성훈,류석용,김경환,김홍용 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: In emergency department, there are many drunken patients with various emergency medical situations. In these patients, evaluation and management of the medical problems are delayed from time to time because of the uncooperative nature of the patients and because of consciousness and sensory changes. A precise evaluation can only be obtained when the patients become sober. For this purpose, most clinicians start IV fluid loading. This study was carried out to evaluate the effect of IV fluid(normal saline and glucose solution) on the rate of ethanol clearance in such patients Methods: Ten volunteers(healthy males in their twenties and with a Michigan alcohol screening test below 4) were enrolled in this study. Alcohol intake was restricted to at least 48 hours before the test and food intake to at least 4 hours. For the test, A predetermined dose of ethanol(1 gm/kg) was given to the volunteers. Each volunteer was tested on three consecutive times with 3 or more days interval for alcohol wash out period . On the lst day, the volunteers received ethanol only per os. On the second day, they received ethanol and a liter of IV 10% dextrose solution. Each day, blood was drawn from the antecubital vein to measure the ethanol level at the time of ethanol ingestion and at 0.5, 1, 1.5, 2, 3, 4, 5 and 6 hours after ingestion. The repeated measure ANOVA test was used for the statistical analysis. Results: The difference in the blood ethanol level between the 3 test was F=1.7, p=0.184 and the difference corrected by the time factor was F=0.32, and p=0.985. Conclusion: There was no significant difference in the blood ethanol level between the tests. In conclusion, the IV normal saline or glucose solution does not accelerate ethanol clearance in suffering

The Role of Natural Analogue in Spent Fuel Disposal Research

Ji-Hun Ryu,Hun Suk Im,Tae-Jin Park,Min-Hoon Baik 한국방사성폐기물학회 2021 한국방사성폐기물학회 학술논문요약집 Vol.2021 No.06

Particulate matters-mediated oxidative stress induces airway inflammation and pulmonary dysfunction through TXNIP/NF-κB and SIRT1/p53/caspase-3 pathways in mice

Ji-Hye Ha,Ba-Wool Lee,Seong-Hun Jeong,Ju-Hong Kim,Do-Hun Kim,Jihye Lee,Hyung-Jun Kwon,Kyungsook Jung,Woo-Sik Kim,Ji-Young Park,Young-Bae Ryu,In-Chul Lee 한국실험동물학회 2022 한국실험동물학회 학술발표대회 논문집 Vol.2022 No.7