Proposal of New Biaxial Fatigue Life Prediction Parameter by Using the Effective Shear Stress for CF8M Stainless Steels

Park, Joong Cheul,Kwon, Jae Do Trans Tech Publications, Ltd. 2005 Key Engineering Materials Vol.297 No.-

<P>A combined axial-torsional low cycle fatigue test was carried out to predict the fatigue life under in-phase and out-out-phase loading conditions for CF8M cast stainless steels. The Fatemi-Socie (FS) parameter which is based on the critical plane approach is not only one of the many methods but also the best method that can predict the fatigue life under a biaxial loading condition. But the result showed that, a biaxial fatigue life prediction by using the FS parameter with several different parameters for the CF8M cast stainless steels is not conservative enough but at the same time it was the best result so far. So in this present research, we proposed a new fatigue life prediction parameter (Park-Kwon parameter) by considering effective the shear stress instead of the FS parameter which considers the maximum normal stress acting on the maximum shear strain and its effectiveness was verified.</P>

복합레진의 지연충전이 미세인장 결합강도에 미치는 영향

박현식,조영곤,박병철,김종욱,최희영,김종진,진철희,유상훈,기영재 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

The purpose of this study was to evaluate the effect of immediate or delayed composite resin filling on dentinal microtensile bond strength (μTBS) after applied the adhesive. The coronal dentin of human third molars was exposed. Single-Bond or One-Step was applied on the dentin surfaces, and composite resin were constructed immediately (group 1) or 5 min., 10 min., 15 min., 20 min. and 30 min. (groups 2-6) after an adhesive was applied. The specimens were sectioned and made bar-shaped. Each surface area of them was about l ㎟. The RBS test was performed by EZ test. The results were analysed by One-way ANOVA and Tukey's test at 95 % significance level. The results suggested that the μTBS of Single-Bond to dentin was decreased when the composite resin was constructed 20 min. and 30 min. after Single-Bond was applied. But the μTBS of One-Step was not affected by delayed composite resin filling.

팥의 RAPD 분석 조건 최적화 연구

이충열,박현철,박진철,김성만,김용철,최재희,최인수 밀양대학교 농업기술개발연구소 2000 農業技術開發硏究所報 Vol.4 No.1

The object of this study was to optimize PCR condition for RAPD analysis in adzuki bean. The best template DNA concentration was 20ng(0.25unit taq polymerase and 2.5mM MgCl2), 40ng(1unit taq polymerase and 2.5mM MgCl2, 1unit taq polymerase and 4.5mM MgCl2 and lunit taq polymerase and 7.0mM MgCl2), and 60ng(0.5unit taq polymerase and 2.5mM MgCl2, 0.5unit taq polymerase and 4.5mM MgCl2, 1unit taq polymerase and 2.5mM MgCl2, and 1unit taq polymerase and 4.5mM MgCl2) The best MgCl2 concentration was 2.5mM(40ng template DNA and 1unit taq polymerase, 60ng template DNA and 0.5unit taq polymerase, and 60ng template DNA and 1unit taq polymerase), 4.5mM(20ng template DNA and 0.25unit taq polymerase, 60ng template DNA and 0.5unit taq polymerase, and 60ng template DNA and 1unit taq polymerase), and 7.0mM(40ng template DNA and 1unit taq polymerase). Amount of taq polymerase was 0.25unit(20ng template DNA and 2.5mM MgCl2), 0.5unit(60ng template DNA and 2.5mM MgCl2, 60ng template DNA and 4.5mM MgCl2) and 1unit(40ng template DNA and 2.5mM MgCl2, 40ng template DNA and 4.5mM MgCl2, 40ng template DNA and 7.0mM MgCl2, 60ng template DNA and 2.5mM MgCl2, 60ng template DNA and 4.5mM MgCl2, and 60ng template DNA and 7.0mM MgCl2). When we consider results from template DNA concentration, MgCl2 concentration, and amount of taq polymerase, the best condition for PCR optimization was 60ng template DNA, 4.5mM MgCl2, and 1unit taq polymerase. Reaction temperatures for the optimal PCR condition were 84℃, 32℃, 62℃; 90℃, 40℃, 72℃; and 92℃, 36℃, 72℃.

동충하초균의 균종과 접종방법에 따른 자실체형성특징

최재희,박진철,김성만,김용철,이충열,박현철,최인수 밀양대학교 농업기술개발연구소 2000 農業技術開發硏究所報 Vol.4 No.1

Effects of photoperiod(23L or 24D) to the growth of the silkworn vegetable wasp and plant worm were investigated. Exposure of the fungi to 24L photoperiod for at least 3 days accelerated the formation of the spore, but the growth of the fruiting bodies was inhibited. On the contrary, 24D photoperiod inhibited the spore formation, but accelerated the growth of fruiting bodies. Accordingly to harvest high quality silkworm vegetable wasp and plant worm, it is suggested that recommendable light condition for production of longer fruiting bodies is 24D photoperiod during the cultivation.

各國 會計制度에 관한 比較硏究 : 美國, 西獨, 프랑스, 韓國

李勉榮,金喆鎬,李聖淳,朴範鎬,宋在萬 弘益大學校 1977 弘大論叢 Vol.9 No.-

One of the new trends in today's world economy is the emergence of increasing actviities of multinational corporations throughtout the world. The total number of foreign investors in Korea for the periods between 1962 and 1976 reaches almost one thousand, while their total value during the same period nearly approaches one billion in U.S. dollars. As their business activities extended beyond their national boundaries in various forms of foreign investment, it has become necessary to gather pertinent accounting information from foreign countries and to convey it to them as needed for the successful conduct of their world-wide business activities. The method of accounting has evolved over a long period of time as a practical technique in a specific context based on their own peculiar settings involving language, law, culture, politics, social and economic factors and the like. It is important, therefore, to understand the accounting systems of foreign countries which contain their respective accounting information so that the useful accounting information can be exchanged between these countries. It is with this objec ivetin view that the accounting systems of U.S., West Germany, France and Korea have been studied in this treatise. Chapter Ⅱ examines their legal rules and regulations on accounting, accounting standards, system, accounting theory and special problems arising from its practical applications. The main characteristics of their accounting systems are analysed and compared with one another in Chapter Ⅲ. The accounting system in the United States has developed from the stand point of investors and managers in line with the regulations set by the Security Exchange Commission (SEC) and under the leading opinions of the American Association of Accounting (AAA) and the American Institute of Certified Public Account (AICPA). In France it was developed and understood from the requirments of national economy, while closely regulated by the Law of Corporation and the Plan Comptable. Germany has developed its accounting system under its Law of Commerce which traditionally stresses the protection of an innocent third party. The development of accounting system in Korea has been unique in that its Law of Commerce was heavily influenced by the German Law of Commerce which is a part of the European continental legal system, while its Law of Security Exchange and it's accounting standards which directly affecting the practices of accounting affairs are under the direct influence of the American accounting system. As has been shown above, the accounting systems of these countries have developed in their unique fashion depending upon their own peculiar environments. However, it should be pointed out that it is the result of research conducted by the AAA and AIPCA which exerts the leading influenced upon the accounting practices of the world. In view of the recent move among the countries of the world to unify their accounting systems, it is hoped that this study will help to facilitate the conduct of international business activities throughout the world.

상아질에 적용된 재 습윤제가 미세인장 결합강도에 미치는 영향

강희영,조영곤,김종욱,박병철,유상훈,진철희,최희영,기영재 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.2

This study investigated that the effect of rewetting agent on dentinal microtensile bond strength (μTBS). Human molars were sectioned to expose the superficial dentin surfaces. Samples were divided into two groups according to type of adhesives-Single Bond (S) and One-Step (0)], and again subdivided into five groups by different dentin surface treatment-dry for 15s (D) , blot dry (BD) or dry for 15s, and rewet with different rewetting agents[distil1ed water (DW), Gluma Desensitizer (GD) and Aqua-Prep (AP)]for 30s. After application of adhesive, composite resin was built up on the bonding surface. Each tooth was sectioned to obtain stick with 1mm^(2) cross sectional area and the μTBS was determined by EZ test. In the S group, the mean μTBS of GD, AP and BD group was significantly higher than that of DW and D group (p < 0.05). In the 0 group, the mean μTBS of AP, GD, BD and DW group was significantly higher than that of D group (p < 0.05). The data suggested that Gluma Desensitizer and Aqua-Prep could be successfully used as rewetting agents, and Distilled water could be acceptable in aceton based adhesive system only.

단일 단계 접착제의 변연 미세누출

조영곤,정진호,기영재,최희영,진철희,유상훈,김종욱,박병철 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.2

This study evaluated the marginal microleakage of five single step adhesives. Class V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on both buccal and lingual surfaces of extracted human molar teeth. Prepared teeth were randomly divided into five groups and restored using one of the single step adhesives and composite resins: Prompt L-Pop/Filtek Z-250 (Group 1), AQ Bond/Metafil CX (Group 2), One-Up Bond F/Palfique Toughwell (Group 3), Futurabond/Admira (Group 4), Xeno III/Spectrum TPH (Group 5). The restored teeth were thermocycled. Microleakage was assessed by dye penetration using 2% methylene blue dye solution. The teeth were bisected buccolingually and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis test and Mann-Whitney tests. The results of this study were as follows; 1. Microleakage of enamel margins in group 3 was statistically higher than that in groups 1, 2, 4, 5 (p < 0.05) 2. Microleakage of dentin margins in group 1 was statistically higher than that in groups 2, 5, and that in group 3 was statistically higher than that in groups 2, 4, 5 (p < 0.05). 3. Dentin marginal microleakage was higher than enamel marginal microleakage in all experimental groups. In conclusion, Prompt L-Pop showed the least leakage at enamel margin, and AQ Bond showed at dentin margin in this study. Marginal miroleakage in dentin was higher than that in enamel.

법랑질 접착에 대한 습윤 효과

고근호,조영곤,진철희,유상훈,김종욱,박병철,기영재,최희영,김종진 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

This study evaluated the microleakage and interfacial gap between enamel and composite resin under the dry and wet condition of the enamel surface, V shaped class 5 cavities were prepared on the occlusal portion of extracted human molars. Samples were divided into three groups: D group (air dry for 10-15s), BD group (blot dry with moist cotton pellet), and DR group (air dry for 10-15s and rewet with Aqua-Prep F for 20s). Cavities were filled using Aelitefil composite resin after applied One-Step. Microleakage was tested by 2% methylene blue dye solution and the data were statistically analysed by Kruskal-Wallis test and Mann-Whitney test. Also Enamel-resin interface was observed under SEM. Group BD showed statistically lower microleakage than group D (p〈0.05). but there was no statistically significant difference between group BD and DR (p)0.05). At the enamel-resin interface, group D showed the gap of 2 ㎛ thickness, but group BD and DR showed close adaptation. In conclusion, the use of blot dry and rewetting agent (Aqua-Prep F) resulted in decreased microleakage and improved adhesion between enamel and resin when using One-Step.

A CASE STUDY ON OPERATION AND MAINTEANCE OF A ZERO-ENERGY BUILDING IN KOREA

Jae Sung PARK,Jae Wan PARK,Jae Bum LEE,Won Jun Choi,U Cheul Shin 한국신재생에너지학회 2015 AFORE Vol.2015 No.11

Prognostic Factors and Scoring Model for Survival in Metastatic Biliary Tract Cancer

Park, Hyung Soon,Park, Ji Soo,Chun, You Jin,Roh, Yun Ho,Moon, Jieun,Chon, Hong Jae,Choi, Hye Jin,Park, Joon Seong,Lee, Dong Ki,Lee, Se-Joon,Yoon, Dong Sup,Jeung, Hei-Cheul Korean Cancer Association 2017 Cancer Research and Treatment Vol.49 No.4

<P><B>Purpose</B></P><P> Metastatic biliary tract cancer (mBTC) has a dismal prognosis. In this study, an independent dataset of patients with mBTC was used to implement and validate a routine clinico-laboratory parameter-based scoring model for risk group identification.</P><P><B>Materials and Methods</B></P><P> From September 2006 to February 2015, 482 patients with mBTC were assigned randomly (ratio, 7:3) into investigational (n=340) and validation datasets (n=142). The continuous variables were dichotomized using a normal range or the best cutoff values determined using the Contal and O'Quigley statistical methods. Following a Cox’s proportional hazard model, the scoring model was derived by summing the rounded chi-square scores for the factors identified by multivariate analysis.</P><P><B>Results</B></P><P> The performance status (Eastern Cooperative Oncology Group 3-4), hypoalbuminemia (< 3.4 mg/dL), carcinoembryonic antigen (≥ 9 ng/mL), neutrophil-to-lymphocyte ratio (≥ 3.0), and carbohydrate antigen 19-9 (≥ 120 U/mL) were identified as independent prognosticators (Harrell’s C index, 0.682; integrated area under the curve, 0.653). Survival was clearly correlated with the risk groups (low, intermediate, and high, 14.0, 7.3, and 2.3 months, respectively; p < 0.001). The prognosis was also discriminative in the validation data set (median survival, 16.7, 7.5, and 1.9 months, respectively; p < 0.001). Chemotherapy did not offer any survival benefits for high-risk patients.</P><P><B>Conclusion</B></P><P> These proposed prognostic criteria for mBTC can facilitate accurate patient risk stratification and treatment-related decision-making.</P>