Hybrid Glass Ionomer cement의 비커스경도와 간접인장강도에 관한 연구

권균원,박상진 大韓齒科保存學會 1997 Restorative Dentistry & Endodontics Vol.22 No.2

The objective of this investigation was to compare the effects of water storage on the aspect of hardness and diametral tensile strengths of four hybrid glass ionomer cements(two compomers and two resin-reinforced glass ionomers) with a resin composite material. One composite resin(Degufill Ultra), two compomers(Dyract, Compoglass Cavifil), and two resin-reinforced glass ionomers(Fuji Duet, Vitremer) were used in this study. Cylindrical specimens were prepared and stored at 36±1℃ in distilled water for 10 minutes after set, and then tested on an Instron testing machine(No.4467) at 1.0mm/min displacement rate. Vicker's hardness and diametral tensile strengths as time elapsed were measured after aging in water for 10 minutes, 1 hour, 3 hours, 1 day, 3 days, 5 days and 7 days at 36±1℃. During the test of diametral tensile strength, stress-strain curves were obtained, from which the compressive modulus were calculated and compared. The structure of four set glass ionomer cement mass was observed on SEM(Hitachi, S-2300) after being etched with 9.6% hydrofluoric acid for 1 minute. The results were as follows; 1. The hardness of the experimental group(compomer and the resin reinforced glass ionomer cement) did not exceed the value of control gorup(Degufill Ultra). 2. Vicker's hardness of the Fuji Duet tended to increase succeedingly, Dyract was decreased after 3 hours in water, and Vitremer was the lowest. 3. The control group(Degufill Ultra) presented progressively on increased diametral tensile strength with time, Fuji Duet were decreased after 3 days, Compoglass Cavifil and Vitremer were decreased after 5 days in water storage. 4. Compressive modulus of the control group(Degufill Ultra) and Dyract were increased sharply timely, Fuji Duet and Vitremer were increased smoothly by lapse of time in water. Fuji Duet were stronger than Vitremer. On the other hand, Vitremer exhibited the lowest toughness. 5. The microstructure of compomer was similar with that of the composite resin(Degufill Ultra), and the fillers in resin-reinforced glass ionomer cements were noticed. It can be concluded that mechanical properties of hybrid glass inomer cements is weaker than composite resin, and that the compomers or the resin-reinforced glass inomers can not substitute the composite resins. A plenty of considerations should be done on the application of them to the area under the loading and high wear has a little adverse effect on the mechanical properties on the water storage for 7 days. The further research should be needed to confirm the advantage of the compomer.

멀티웨이브릿 변환 기반에서 통계적 추정 이론을 이용한 적응 워터마킹 기술에 관한 연구

권기룡,강균호 부산 외국어 대학교 2003 外大論叢 Vol.26 No.-

We propose adaptive watermarking using stochastic estimation theory based on multiwavelet transform in this paper. To embed watermark, the original image is decomposed into 4 levels using a discrete multiwavelet transform, then a watermark is embedded into the perceptual significant coefficients, PSCs larger than the JND (just noticeable differences) threshold of the each subband. We use DGHM multiwavelet that has approximation order 2. The JND threshold is to achieve watermark transparency and it determine the length of watermark signal. The experimental results of computer simulation of the proposed adaptive watermarking method were found to be excellent invisibility and robustness.

은행엽 물추출물이 흰쥐의 흉부대동맥 혈관이완에 미치는 영향

鄭權洙,金亨煥,安德均,崔湖榮 대한본초학회 2001 大韓本草學會誌 Vol.16 No.2

We have examined the relaxational response of the Ginkgo Folium water extract on isolated thoracic aorta from sprague dawley rat (300~350g) in the presence and absence of endothelium and the vasodilator nitric oxide. Segments of thoracic aorta obtained from rats immediately after delivery were mounted in organ baths superfused on a polygraph. We found that the thoracic aorta segments responded to the Ginkgo Folium water extract with a dose-dependent vasorelaxation. At 2.0 ㎎/㎖ Ginkgo Folium water extract, the relaxational response with and without endothelium were 75.8% and 6.9% of the maximum KCI-response. The Phenylepinephrine and 5-hydroxytrptamine - induced contraction at 10^-4M were inhibited by 77.3% and 75.8% after addition(2.0 ㎎/㎖) of the Ginkgo Folium water extract. After pre-treatment of the thoracic aorta with N^G-monomethyl-L-arginine(10^-4M), the vessels contracted in response to the nitric oxide synthase inhibitor. The present results show that nitric oxide may act as a crucial signal in the vasodilative action. In conclusion, Ginkgo Folium water extract-induced relaxation in the isolated rat thoracic aorta was composed of endothelium-dependent and dose-dependent relaxation. Endothelium-dependent relaxation may be mediated by release of endothelium derived relaxing factor, nitric oxide.

국립대학교 강의인건비 계산모형에 관한 연구

지성권,이균봉,정준수 釜山 大學校 經營 經濟 硏究所 2001 經營 經濟 硏究 Vol.20 No.1

최근 복수전공, 자유전공, 심화전공, 그리고 학부제 등이 도입됨에 따라 특정전공교육이 다른 전공이 제공하는 강의서비스에 의존하는 정도가 증가하고 있는 실정이다. 따라서 전공별 또는 원가대상별 강의용역상호수수관계를 고려하지 않고는 정확한 원가계산이 불가능하다. 본 연구에서는 첫째 강의인건비를 집계하는 과정에서 사용할 강의용역상호수수관계를 파악하는 방법을 제시하였다. 둘째, 교육원가계산에 있어서 고려해야 할 중요한 요인인 교육원가대상을 정의하는 방법을 제시하였다. 본 연구에서는 전임교수의 인건비 중 급여성 연구비는 연구활동비로 분류하지 않고 강의인건비에 포함시키는 방법을 제시하였다. 그리고 전임교수 인건비를 강의용역상호수수관계를 파악하여 교육원가대상에 배분할 때 원가대상의 실제 강의인건비를 사용하지 않고 원가대상이 소속된 대학별로 강의시간당 평준화 인건비를 사용하였다. 그리고 특정대학에 소속된 원가대상의 강의수수 양태가 동일한 대학에 소속된 다른 원가대상과 확연하게 다르다고 생각되는 경우에는 대학별 평준화 인건비를 사용하지 않고 학과(부)별 평균인건비를 사용하는 것이 합리적이다. 시간강사인건비는 대학별로 시간당 평균인건비를 계산하지 않고 부산대학교 전체의 강의시간 당 평균인건비를 계산하여 사용한다. 본 연구에서는 교육원가대상을 학부(과)의 경우에는 기초과정, 전공과정, 일반대학원과정을 개별 원가대상으로 정의하였고 특수대학원은 전공별로 원가대상으로 분류하였다. 그리고 교육원가대상이 대학의 구조조정에 따라 달라지는 경우에는 교육원가계산을 수행하는 연도의 학제를 기준으로 교육원가대상을 정의하였다.

분산 시스템에서 개선된 O(logN) 상호배제 알고리즘 제안

송권수,오병균 木浦大學校 情報産業硏究所 1993 情報産業硏究誌 Vol.1 No.-

본 논문은 분산 시스템에서 수행시간이 O(logN)으로 개선된 토큰 중심의 상호배제 알고리즘을 제안하였다. 이 알고리즘에서, 논리적 트리는 완전 연결(fully connected) 네트워크를 유지하며, 루트(Root)는 메세지 전송이 없을때 병행 요청 사이트들 가운데 토큰을 갖는 마지막 사이트이다. 사이트가 상호배제를 필요로 할 때, 그사이트는 토큰을 갖을 수 있는 사이트에 요청 메세지를 보내는 작업을 요청 메세지가 Root에 도착할 때까지 계속해 나간다. 따라서, 토큰을 탐색하는 메세지의 수는 Root에 도달하는 길(path)의 사이트 수에 비례한다. 토큰의 탐색속도를 향상시키기 위하여 알고리즘은 논리적 트리의 높이(hight)를 줄인다. 알고리즘의 메세지 수행시간은 N이 사이트의 수 일때 가벼운 traffic에서는 O(logN)이고, 복잡한 traffic에서는 3개를 감소한다. 본 알고리즘의 중요한 특성은 분산된 큐자료 구조를 사용하며, 이 구조는 토큰으로 자료 구조를 간단히 할 뿐 아니라 타임스탬프나 무한 수열의 사용을 제거하므로 신뢰도를 높여준다. In this paper, we present an O(logN) token-based mutual exclusion algorithm for distributed systems. In the algorithm, a logical tree is maintained in a fully connected network, and the root is the last site to get the token among the current requesting sites when no message is in transmission. When a site invokes mutual exclusion, it send its request to the site possibly holding the token. The request is continuously forwarded until it arrives at the root. Therefore, the number of messages for the search of the token is proportional to the number of sites on the path leading to the root. To speed up the research for the token, the algorithm reduces the hight of the logical tree. The message complexity of the algorithm is O(logN) in light traffic, where N is the number of sites, and is reduced to three in the heavy traffic. An interesting characteristic of the algorithm is the use of distributed queue data structure. The distributed queue data structure simplifies the data structure in the token, dispenses with the use of unbounded sequence numbers or timestamps, and provides a high degree of reliability.

체외충격파 쇄석술 시행 후 5년 뒤 발생한 요관 협착 및 농신장 1예

이현승,권균홍,조용건,김봉진,임창섭,김자영,허동,임학 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.4

A 40-years-old woman was admitted to this hospital with flank pain and high grade fever for 2 weeks. As a matter of her past history, extracorporeal shock wave lithotripsy (ESWL) was performed for treatment of renal stones 5 years ago. Her abdominal CT findings were hydronephrosis with pyonephrosis and renal stones. Antibiotics administered for 5 days had no effects on her symptom improvement. A right ureteral stricture was noticed by ultrasonography follow up. We inserted double J stent and continued antibiotics therapy for 10 days, and then her fever was disappeared and flank pain was improved. ESWL is one of the most important treatment of renal and ureteral stone. However, its complications should not be negligible including bleeding, pain, ureteral obstruction, infection and so on. Complications of ESWL can be divided into acute and chronic courses. When we treat pyelonephritis patient with past history of ESWL, possibility of ureteral stricture must also be considered. In this study we report a case of pyelonephritis caused by ureteral stricture, possibly as a chronic complication of ESWL performed 5 years earlier

폐결핵치료 중인 환자에서 Rifampicin에 의해 유발된 위막성 대장염 2예

김봉진,권균홍,임창섭,김자영,홍정범,옥미선,배용목,김지연 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.4

Pseudomembranous colitis (PMC) is a disease caused by Clostridium difficile proliferation. The causative drugs are clindamycin, third-generation cephalosporins, flouroquinolone and so on. Rifampicin has been reported as a cause of PMC in the 1980s, and the frequency of PMC is increasing because rifampicin is a first line drug for anti-tuberculosis therapy. Two patients were recently admitted to our hospital due to watery diarrhea for 1 month and they were diagnosed with PMC by sigmoidoscopy. Their onset age were 74, 72 years old and latent period of symptoms were 60, 129 days, respectively. In one case, the patient displayed coexisting hypertension and diabetes. The clinical symptoms improved after discontinuing the rifampicin and then administering oral metronidazole. We report here on two cases presumed to be rifampicin-induced PMC.

효율적인 네트워크 관리를 위한 사용자 인터페이스에 관한 연구

김만택,송권수,오병균 木浦大學校 情報産業硏究所 1995 情報産業硏究誌 Vol.3 No.-

Network management provides us with configuration management function, fault management function, performance management function, account management function, and security management function. A good Graphical User Interface(GUI) has been requested for users or network managers to monitor networking and to correct problems. In this thesisr, We design and implement GUI for a network management protocol used in the heterogeneous distributed environment. The designed GUI is developed by using Motif. Users easily select the managed object on the graphical map and execute commands through pulldown menus that are controlled by MWM. Our SNMP API provided access to MIB table to perform management operations, to set up the agent, and to include functions that return values of MIB.

내시경역행성담췌관조영술 후 발생한 종격동기종, 피하공기증, 긴장성 기흉 1예

조용건,이현승,권균홍,김자영,김봉진,김지연,배용목,박선자 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.4

However, Endoscopic retrograde cholangiopancreatography (ERCP) is still helpful procedure for the diagonosis of the pancreatobiliary disease and treatment through endoscopic sphinterectomy (EST) is relatively safe, these have possiblity of complications such as hemorrhage, infection, panceatitis, and perforation. ERCP related perforation was rarely reported in 0.3 to 1.1% of previous study, but most serious complication. A report of Pneumomediastinum, Tension Pneumothorax complicating perforation after ERCP and EST is very uncommon. In our hospital, we experienced case of pneumomediastinum, subcutaneous emphysema, and tension pneumothorax after ERCP and EST, and the patient (a 58 years old female with suspicious common bile duct stone) was treated successfully with conservative treatment.

Color Variation Improvement by Introducing Double Emission Layers in WPLEDs

Kwon, Soon Kab,Lee, Yong Kyun,Park, Tae Jin,Jeong, Su Hyeon,Jeon, Woo Sik,Jang, Jin,Kwon, Jang Hyuk TaylorFrancis 2007 Molecular Crystals and Liquid Crystals Vol.470 No.1

<P> We have fabricated white polymeric light-emitting devices (WPLEDs) from polyfluorene-based (PFO) blue and MEH-PPV polymer blending systems. A device structure of ITO/PEDOT:PSS/Blending polymer/Blue polymer/LiF/Al was employed. This double emissive structure results in the significant improvement of white color shift phenomenon. A current efficiency of 4.67 cd/A (3,900 cd/m2, 6.4 V) and a brightness value of 17,600 cd/m2 at 9.4 V with (0.34, 0.35) CIE coordinates at 5 V and (0.29, 0.29) at 9 V were obtained.</P>