ALMOST SURE CONVERGENCE FOR WEIGHTED SUMS OF NA RANDOM VARIABLES

BAEK J. I.,NIU S. L.,LIM P. K.,AHN Y. Y.,CHUNG S. M. The Korean Statistical Society 2005 Journal of the Korean Statistical Society Vol.34 No.4

Let {$X_n,\;n{\ge}1$} be a sequence of negatively associated random variables which are dominated randomly by another random variable. We discuss the limit properties of weighted sums ${\Sigma}^n_{i=1}a_{ni}X_i$ under some appropriate conditions, where {$a_{ni},\;1{\le}\;i\;{\le}\;n,\;n\;{\ge}\;1$} is an array of constants. As corollary, the results of Bai and Cheng (2000) and Sung (2001) are extended from the i.i.d. case to not necessarily identically distributed negatively associated setting. The corresponding results of Chow and Lai (1973) also are extended.

Stretchability and drawability of twinning-Induced plasticity steel-Cored layer steel sheets

Kim, J.G.,Baek, S.M.,Yoon, J.I.,Seo, M.H.,Cho, W.T.,Chin, K.-G.,Lee, S.,Kim, H.S. Elsevier 2017 Journal of materials processing technology Vol. No.

<P>In this work, the qualCONVERSION(0ities of sheet formability (i.e., stretchability and drawability), of twinning-induced plasticity (TWIP), steel-cored thr$ee-layer steel sheets were investigated in terms of tensile parameters (i.e., strain hardening exponent, strain rate sensitivity, normal anisotropy, mean R-value, and total elongation). The tensile parameters of TWIP steel-cored three-layer steel sheets follow the force-based rule of mixtures. The limit drawing ratio, the measure of drawability, of the three-layer steel sheet was proportional to the mean R-value and the strain rate sensitivity while the limit dome height (LDH), the measure of stretchability, could not be correlated with any tensile parameters. The LDH of the TWIP steel-cored layer sheet was superior to that of the single layer due to the inhibition of serration in the TWIP steel-core during the Erichsen test.</P>

Construction and Commissioning of the KSTAR Helium Distribution System

Lee, Y.J.,Park, Y.M.,Kim, Y.S.,Jang, H.S.,Kwag, S.W.,Chang, Y.B.,Park, H.T.,Woo, I.S.,Song, N.H.,Bang, E.N.,Ha, T.H.,Baek, S.,Kim, M.K.,Kim, W.C.,Oh, Y.K.,Bak, J.S. IEEE 2009 IEEE transactions on applied superconductivity Vol.19 No.3

<P>The KSTAR components requiring cryogenic helium coolant for superconducting magnet operations are connected to the helium refrigeration system (HRS) through the helium distribution system (HDS), the final helium distribution station. Twenty eight cryogenic valves including 4 quench protecting valves, many sensors such as temperature sensors, pressure transmitters, and flowmeters are mounted on the system. The HDS has to control the 4.5 K supercritical helium (600 g/s) for 30 superconducting coils and their superconducting bus-lines, 55 K helium (270 g/s) pressurized to 18 bars for the thermal shields and the gravity supports, and a maximum 17.5 g/s of liquid helium for 18 current leads, provided from the HRS which has a 4.5 K equivalent cooling power of 9 kW. The helium distribution system consists of a helium distribution box (DB), 5 helium transfer lines, a PLC based helium control system (HCS), etc. The helium control system is connected to the KSTAR supervisory control & interlock system. The detailed status regarding the construction, commissioning during first cool-down, and the instrumentation & control (I&C) system are included in this paper.</P>

Prognostic factors for classifying extranodal NK/T cell lymphoma, nasal type, as lymphoid neoplasia

Na, Im I.,Kang, Hye J.,Park, Yeon H.,Lee, Seung-Sook,Yoo, Hyung J.,Choe, Du H.,Ryoo, Baek-Yeol,Yang, Sung H. Blackwell Publishing Ltd 2007 European journal of haematology Vol.79 No.1

<P>Abstract</P><P>This study evaluated the applicability of prognostic factors commonly used for diagnosis of classical lymphoma outcomes to extranodal NK/T cell lymphoma, nasal type (NTCL). Clinical features and their associations with lactate dehydrogenase (LDH) were evaluated in 70 patients. RLDH was defined as the ratio of LDH to the upper normal limit. RLDH was associated with stage (I–II vs. III–IV), lymph node involvement (LNI), and International Prognostic Index score (<2 vs. ≥2). Poor performance status and advanced stage were common in patients with local tumor invasiveness (LTI). LDH level, classified into three levels (low, high, and very high) was associated with survival (<I>P</I> < 0.001). In multivariate analysis, the predictive values of LDH level, B symptom, performance status, and stage remained significant whereas those of LTI and LNI did not. Scoring was performed by weighting each factor with 0.5 or 1.0 according to its hazard ratio. Scores were classified into four groups. Groups with high scores were associated with unfavorable outcomes (<I>P</I> < 0.001). Current study suggests that prognostic factors for NHL may be useful to predict the outcome of NTCL but the model should take LDH level and the prognostic weight of each factor into account.</P>

Genetic diversity of the VP7, VP4 and VP6 genes of Korean porcine group C rotaviruses

Jeong, Y.J.,Matthijnssens, J.,Kim, D.S.,Kim, J.Y.,Alfajaro, M.M.,Park, J.G.,Hosmillo, M.,Son, K.Y.,Soliman, M.,Baek, Y.B.,Kwon, J.,Choi, J.S.,Kang, M.I.,Cho, K.O. Elsevier Scientific Pub. Co 2015 Veterinary microbiology Vol.176 No.1

Porcine group C rotaviruses (RVCs) are considered important pathogens due to their economic impact on pig industry and may also cross the host species barrier toward humans. Unlike RVA, however, genetic and phylogenetic data on RVCs from pigs and other host species are scarce. In the present study, full-length ORF sequences of 26 VP7, 9 VP4 and 9 VP6 genes of Korean porcine RVC strains were compared with those of other known RVC strains by phylogenetic analyses and pairwise identity frequency graphs. Applying the established 85% nucleotide identity cut-off value for RVC VP7 classification, the 26 Korean porcine RVC strains belonged to the G1, G3, G6 and G7 genotypes. Although more complete RVC VP4 sequences are warranted before a definitive cut-off value could be determined, a provisional 83% nucleotide cut-off value proposed for RVC VP4 classification resulted in 7 P-genotypes, 5 of which possessed porcine RVC strains. A 90% nucleotide cut-off value for VP6 divided RVC strains into 7 I-genotypes, 5 of which had porcine RVC strains. G/P/I-genotype comparisons suggested the occurrence of rather frequent reassortment events among Korean porcine RVC strains, and strong geographical differences in the distribution of RVC G-genotypes worldwide. Our data indicate that a large genetic diversity exists among porcine RVC strains. For the final genotype determination of each gene segment, more intensified epidemiological studies on animal and human RVC strains throughout the world are needed.

Simultaneous Removal of Algae and Their Secondary Algal Metabolites from Water by Hybrid System of DAF and PAC Adsorption

Roh, S. H.,Kwak, D. H.,Jung, H. J.,Hwang, K. J.,Baek, I. H.,Chun, Y. N.,Kim, S. I.,Lee, J. W. Taylor Francis 2008 Separation science and technology Vol.43 No.1

<P> The feasibility of a hybrid system consisting of powdered activated carbon (PAC) adsorption and dissolved air flotation (DAF) processes was examined for the simultaneous removal of algae (anabaena and mycrocystis) and their secondary algal metabolites (2-methylisoboneol and geosmin). Before studying the hybrid system, adsorption equilibrium and kinetics of organics (2-methylisoboneol and geosmin) produced from algae on three powdered activated carbons (wood-based, coal-based, coconut-based) were studied. The flotation efficiency of algae and PAC in DAF process was evaluated with zeta potential measurements. Interestingly, we found that the agglomerate of bubble and PAC particle can be successfully floated by DAF. In addition, the simultaneous removal of algae and organics (i.e., secondary algal metabolites) dissolved in water can be achieved by using the hybrid system of adsorption/DAF processes.</P>

혈관조영술 소견에 중점을 둔 Buerger's병의 임상적 고찰

황종익,김수신,백세민 大韓成形外科學會 1987 Archives of Plastic Surgery Vol.14 No.2

Thromboangitis obliterans has been recognized clinical entity for more than half a century (Leo Buerger 1908). Buerger's disease is a specific recurrent, segmental, inflammatory, obliterative vascular disease involving principally the medium sized artery and vein and its classic type occurs relatively frequently in Orient, Korea and Japan, despite the rarity of atherosclerosis and of thromboembolic disease. 95 cases with Buerger's disease among the peripheral vascular occlusive disease were experienced at Department of Plastic and Reconstructive Surgery in Korea University Guro Hospital between January 1984 and March 1986. We made clinical study for this patients and the results were as follows: 1. All patients were male and the majority of the patients were between the age of 21 and 50 years, at onset of symptoms with range being 21 to 40. 2. Patients except 5 cases and smoked heavily at the onset of their symptoms with pain, claudication coldness and necrosis. 3. The most common extremities affected were both lower extremities, 19 cases revealed involvement of the both upper and lower extremities, and 1 case showed involvement of only upper extremities. 4. The most common sites of obstruction were, posterior tibial artery, anterior tibial artery and superficial femoral artery in femoral angiogram, and ulnar artery, radial artery and deep palmar arch in brachial angiogram in that order of frequency. 5. In 33 of 95 patients, it was possible to undertake 26 micro-endarterectomy, bypass in 1, micro-endarterectomy combined with bypass graft in 3, micro-endarterectomy with amputation in 1, and amputation in 2. Among the endarterectomy cases, we experienced 4 cases of reocclusion within 6 month and only 1 case showed poor prognosis, amputation.

공작 기계의 이송계 제어 최적화에 관한 연구

박인준,백형래 조선대학교 에너지.자원신기술연구소 1997 에너지·자원신기술연구소 논문지 Vol.19 No.2

This paper is a study about motor technic of feed drive system control and Feedforward control in order to shape cutting control on the machine tool. The shape error caused by delay of the servo system in the direction of radius at the time of circular cutting is reduced by Feedforward control, shape error generated by the position command delay is minimized by using the acceleration/deceleration time constant after the interpolation. The study was verified to optimization of feed drive system control on experiments of a vertical machining center of the machine tool.

수정된 화학전이 NMR 영상법에 의한 수분과 지질의 비율 측정에 관한 연구

신용진,장차익,홍광준,유상하,이관교,양경승,백창현,김남수,정준우 조선대학교 기초과학연구소 1996 自然科學硏究 Vol.19 No.1

다양한 화학종(化學種)의 선택적인 핵자기공명(nuclear magnetic resonance, NMR) 영상(imaging)을 얻기 위한 몇몇 기술들이 가장 일반적인 Dixon's, CHESS, SECSI 등 3가지 방법들과 함께 발전해 왔다. 모든 화학전이 영상법(chemical shift imaging method)에 있어서 가장 큰 문제점은 정자기장의 균일성과 RF(radiofrequency) 코일에 대전된 시료가 인가되었을 때 나타나는 자기장의 찌그러짐이다. 만약 자기장의 shimming이 없다면, 약 3.5ppm으로 분리된 수분(water)과 지질(fat)의 선택적 양성자 영상을 얻는데 위 세 가지 방법들은 이용될 수 없다. 2.5ppm에서 3.5ppm의 선폭(linewidth)을 가진 시료(phantom)를 이용한 실험으로 위의 세 가지 기술과 새로운 화학전이 영상기술을 정량적으로 분석할 수 있었다. 본 연구에서는 선택적인 포화(saturation)와 재집중(refocusing) pulse가 포함된 새로운 화학전이 영상기술(modified CHESS+SECSI technique)이 다양한 시료에서 수분과 지질의 정량적 비율을 측정하는데 이용될 수 있도록 개발되었다. There are several methods developed to achieve selective NMR image of differing chemical species with the three most popular being Dixon's, CHESS, and SECSI, A major problem common to all chemical shift imaging methods is the uniformity of the static magnetic field and distortions introduced when RF coils are loaded with a conducting specimen. Without magnetic field shimming, these methods cannot be used to selectively image protons in fat and water which are separated by approximately 3.5ppm. Experiments with a phantom, with linewidths of 2.5 to 3.5ppm, were quantitatively evaluated for the above three methods and a new chemical shift imaging method. In this study the new chemical shift imaging method (modified CHESS+SECSI technique) which included a selective saturation and refocusing pulse, was developed to determine the ratio of water and fat in different samples.

화상시 T세포 및 자연살해 세포면역능의 변화에 관한 실험적 연구

김영진,백무현,엄익태,조문제,임풍 大韓成形外科學會 1989 Archives of Plastic Surgery Vol.16 No.2

Studies of the immune system in both clinicl and experimental burn injury have noted impairment of cellular immunity and this impaired cellular immunity after burn has been demonstrated by prolonged survival allograft, marked depression on delayed hypersensitivety or failure of lymphocyte mitogenesis. However, the exact nature of the mechanisms leading to immunosuppression remains unclear. The aim of this study is to evaluate the level of cellular immunity in burned rats with immune paramenters of T cell subsets and colony forming unit-T lymphocyte (CFTL) as well as natural killer cell mediated cytotoxicity (NKMC). Lymphocytes were isolated sequentially from the blood of control and experimental animals on the 1st, 3rd, 5th, 7th and 14th postburn days (PBD). T-cell subsets were defined with monoclonal anti rat T lymphocyte antibody by the indirect immunofluoroscence method. The proportions of tatal T cell (Tan T), helper T cell (Th) and helper T cel/suppressor T cell ratio decreased from the 1st PND and revealed most significant reduction on the 5th PBD (Pan T)and 7th PBD (Th, Th/Ts ratio)respectively, but they recovered by the 14th PBC. On the contrary, the percentage of suppressor T cell (Ts) in creased after burn injury and was maximum on the 7th PBD, thereafter it decreased to the nearly control level on the 14th PBD, Number of T-lymphocyte colony (TL-colony) decreased after burn injury, and the changing pattern of its number was quite similar to that of Pan T. The cytotoxicity of natural killer cell against Molt 4 target cells depressed rapidly after burn injury and revealed most significant reduction on the 3rd PBD, but it restored completely on the 7th PBD. Sequential change of cortisol level didn't co-ordinate with that of cellular immunity, and it showed that stress after burn injury did not frnction as a major role to decrese cellular immunity. The results of this study give us a speculation that immunosuppression after burn injury was resulted from decreased helper T cell, increased suppressor T cell and depressed NKMC, and that damage or recovery fo natural killer cells after burn injury is of precedence to that of the T cells.