• Title/Summary/Keyword: frontier function

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Expressed Sequence Tag Analysis of the Erythrocytic Stage of Plasmodium berghei

  • Seok, Ji-Woong;Lee, Yong-Seok;Moon, Eun-Kyung;Lee, Jung-Yub;Jha, Bijay Kumar;Kong, Hyun-Hee;Chung, Dong-Il;Hong, Yeon-Chul
    • Parasites, Hosts and Diseases
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    • v.49 no.3
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    • pp.221-228
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    • 2011
  • Rodent malaria parasites, such as Plasmodium berghei, are practical and useful model organisms for human malaria research because of their analogies to the human malaria in terms of structure, physiology, and life cycle. Exploiting the available genetic sequence information, we constructed a cDNA library from the erythrocytic stages of P. berghei and analyzed the expressed sequence tag (EST). A total of 10,040 ESTs were generated and assembled into 2,462 clusters. These EST clusters were compared against public protein databases and 48 putative new transcripts, most of which were hypothetical proteins with unknown function, were identified. Genes encoding ribosomal or membrane proteins and purine nucleotide phosphorylases were highly abundant clusters in P. berghei. Protein domain analyses and the Gene Ontology functional categorization revealed translation/protein folding, metabolism, protein degradation, and multiple family of variant antigens to be mainly prevalent. The presently-collected ESTs and its bioinformatic analysis will be useful resources to identify for drug target and vaccine candidates and validate gene predictions of P. berghei.

Static Type Inference Based on Static Single Assignment for Bytecode (바이트코드를 위한 정적 단일 배정문 기반의 정적 타입 추론)

  • Kim Ji-Min;Kim Ki-Tea;Kim Je-Min;Yoo Weon-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.4 s.42
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    • pp.87-96
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    • 2006
  • Although bytecode has many good features, it has slow execution speed and it is not an ideal representation for program analysis or optimization. For analysises and optimizations. bytecode must be translated to a Static Single Assignment Form(SSA Form) But when bytecode is translated a SSA Form it has lost type informations of son variables. For resolving these problem in this paper, we create extended control flow graph on bytecode. Also we convert the control flow graph to SSA Form for static analysis. Calculation about many informations such as dominator, immediate dominator. dominance frontier. ${\phi}$-Function. renaming are required to convert to SSA Form. To obtain appropriate type for generated SSA Form, we proceed the followings. First. we construct call graph and derivation graph of classes. And the we collect information associated with each node. After finding equivalence nodes and constructing Strongly Connected Component based on the collected informations. we assign type to each node.

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Vibration analysis and optimization of functionally graded carbon nanotube reinforced doubly-curved shallow shells

  • Hammou, Zakia;Guezzen, Zakia;Zradni, Fatima Z.;Sereir, Zouaoui;Tounsi, Abdelouahed;Hammou, Yamna
    • Steel and Composite Structures
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    • v.44 no.2
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    • pp.155-169
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    • 2022
  • In the present paper an analytical model was developed to study the non-linear vibrations of Functionally Graded Carbon Nanotube (FG-CNT) reinforced doubly-curved shallow shells using the Multiple Scales Method (MSM). The nonlinear partial differential equations of motion are based on the FGM shallow shell hypothesis, the non-linear geometric Von-Karman relationships, and the Galerkin method to reduce the partial differential equations associated with simply supported boundary conditions. The novelty of the present model is the simultaneous prediction of the natural frequencies and their mode shapes versus different curvatures (cylindrical, spherical, conical, and plate) and the different types of FG-CNTs. In addition to combining the vibration analysis with optimization algorithms based on the genetic algorithm, a design optimization methode was developed to maximize the natural frequencies. By considering the expression of the non-dimensional frequency as an objective optimization function, a genetic algorithm program was developed by valuing the mechanical properties, the geometric properties and the FG-CNT configuration of shallow double curvature shells. The results obtained show that the curvature, the volume fraction and the types of NTC distribution have considerable effects on the variation of the Dimensionless Fundamental Linear Frequency (DFLF). The frequency response of the shallow shells of the FG-CNTRC showed two types of nonlinear hardening and softening which are strongly influenced by the change in the fundamental vibration mode. In GA optimization, the mechanical properties and geometric properties in the transverse direction, the volume fraction, and types of distribution of CNTs have a considerable effect on the fundamental frequencies of shallow double-curvature shells. Where the difference between optimized and not optimized DFLF can reach 13.26%.

Stability investigation of symmetrically porous advanced composites plates via a novel hyperbolic RPT

  • S.R. Mahmoud;E.I. Ghandourah;A.H. Algarni;M.A. Balubaid;Abdelouahed Tounsi;Abdeldjebbar Tounsi;Fouad Bourada
    • Steel and Composite Structures
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    • v.46 no.4
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    • pp.471-483
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    • 2023
  • This paper presents an analytical hyperbolic theory based on the refined shear deformation theory for mechanical stability analysis of the simply supported advanced composites plates (exponentially, sigmoidal and power-law graded) under triangular, trapezoidal and uniform uniaxial and biaxial loading. The developed model ensures the boundary condition of the zero transverse stresses at the top and bottom surfaces without using the correction factor as first order shear deformation theory. The mathematical formulation of displacement contains only four unknowns in which the transverse deflection is divided to shear and bending components. The current study includes the effect of the geometric imperfection of the material. The modeling of the micro-void presence in the structure is based on the both true and apparent density formulas in which the porosity will be dense in the mid-plane and zero in the upper and lower surfaces (free surface) according to a logarithmic function. The analytical solutions of the uniaxial and biaxial critical buckling load are determined by solving the differential equilibrium equations of the system with the help of the Navier's method. The correctness and the effectiveness of the proposed HyRPT is confirmed by comparing the results with those found in the open literature which shows the high performance of this model to predict the stability characteristics of the FG structures employed in various fields. Several parametric analyses are performed to extract the most influenced parameters on the mechanical stability of this type of advanced composites plates.

Inefficiencies and Productivity Change of Domestic Banks including Non-performing Loan with Normal Output after Financial Crisis (금융위기 이후 부실채권을 고려한 국내 은행의 비효율성과 생산성 변화)

  • Chang, Young-Jae;Yang, Dong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.91-102
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    • 2020
  • This study constructed production frontiers of inputs and outputs in a sequential manner, measured inefficiencies by applying a non-radial sequential weighted Russell directional distance function to these frontiers, and analyzed Luenberg productivity indices and the contribution of each of input and output factor based on these distances. The results are as follows. First, the productivity of banks increased due to technical changes after the global financial crisis. Second, productivity growth decreased between 2009 and 2014 due to technical changes after the recession, as previous studies have shown that technology progressed before the global financial crisis but then largely decreased or remained the same thereafter. After 2014, the productivity of banks improved. This result may be due to both technology improvement after 10 years of stagnation and reduction of inputs and non-performing loans. Third, the 3.6% annual of productivity growth for 10 years was comprised of 1.77% household loans, 0.67% corporate loans, 0.98% manpower, 1.18% non-performing loans, -0.5% total deposits, and -1.25% securities. Finally, this study has limitations since it could not control risks such as capital structure and interest volatility.

Relative Stability, Ionization Potential, and Chemical Reactivity of the Neutral and Multiply Charged $C_{60}$ (중성과 다중 전하를 가진 $C_{60}$의 상대적 안정도, 이온화 에너지 및 화학 반응성)

  • Sung, Yong Kiel;Son, Man Shick
    • Journal of the Korean Chemical Society
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    • v.41 no.3
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    • pp.117-122
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    • 1997
  • On the basis of our previous paper[Bull. Korean Chem. Soc. 1995, 16, 1015], the relative stability, ionization potential, and chemical reaction of the neutral and multiply charged $C_{60}$n ions(n=3+ to 6-) have been investigated by the semi-empirical MNDO method. $C_{60}^{1-}$ has the highest stability. The ionization potential values of the $C_{60}$ ions range from 15.31 eV of $C_{60}^{2+}$ to -13.01 eV of $C_{60}^{6-}$. These values show a linear relationship according to charges. The average IP per charge is 3.15 eV from our calculations and 3.22 eV from the linear function of IP. A charge- or electron-transfer reaction of $C_{60}^{n+}$ will only occur if the ionization potential of any guest molecule is lower than the electron affinity of the host $C_{60}^{n+}$. If the energy gap between ionization potential and electron affinity, ${\Delta}_{IP-EA}$, is high, charge-transfer reactions arise by the charge-controlled effect. However, if ${\Delta}_{IP-EA}$ is low, electron-transfer reactions arise by the frontier-controlled effect.

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Practice and Theory of RYUTSUKEIRETSUKA(Vertical Marketing System) by the Japanese Leading Manufacturers (일본 과점메이커의 유통계열화의 현실과 이론)

  • Choi, Sang-Chul
    • Journal of Distribution Research
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    • v.16 no.5
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    • pp.211-231
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    • 2011
  • RYUTSUKEIRETSUKA(Vertical Marketing System) developed by the Japanese Leading Manufacturers began to turn weak with the presence of the large- scaled retail enterprises since 1980’s. Therefore the alliances between major manufacturers & large distributors that were in the conflict relations for a long time began to progress. In accordance with this change in the distribution channel practice, the stance of the distribution channel theory in Japan had also changed. As the normative researcher group who had been critical to RYUTSUKEIRETSUKA and sympathetic to the task of merchant judged that it would disappear sooner or later, they considered positively the alliances between major manufacturers & large distributors which the latter were in dominant position. On the other hand, even the empirical researchers who supported the affirmative function of RYUTSUKEIRETSUKA changed their standpoint. They recognized the new channel practice, in other words the vertical alliances between the power companies, would be the frontier of research in accordance with the impetus of positivism in terms of the Marketing methodology. Thus, researchers of distribution channel theory in Japan who supported the normative approach become few and even changed to hurry to absorb in the empirical research, while moving the main focus of the research from RYUTSUKEIRETSUKA to the Alliances. In the long run, the distribution channel theory which was regarded as the leading principle of the Japanese Marketing has just made the methodological paradigm shift. The author suggests a critical viewpoint against the current Japan’s academism with the assumption that RYUTSUKEIRETSUKA has negative aspects.

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Technical Inefficiency in Korea's Manufacturing Industries (한국(韓國) 제조업(製造業)의 기술적(技術的) 효율성(效率性) : 산업별(産業別) 기술적(技術的) 효율성(效率性)의 추정(推定))

  • Yoo, Seong-min;Lee, In-chan
    • KDI Journal of Economic Policy
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    • v.12 no.2
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    • pp.51-79
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    • 1990
  • Research on technical efficiency, an important dimension of market performance, had received little attention until recently by most industrial organization empiricists, the reason being that traditional microeconomic theory simply assumed away any form of inefficiency in production. Recently, however, an increasing number of research efforts have been conducted to answer questions such as: To what extent do technical ineffciencies exist in the production activities of firms and plants? What are the factors accounting for the level of inefficiency found and those explaining the interindustry difference in technical inefficiency? Are there any significant international differences in the levels of technical efficiency and, if so, how can we reconcile these results with the observed pattern of international trade, etc? As the first in a series of studies on the technical efficiency of Korea's manufacturing industries, this paper attempts to answer some of these questions. Since the estimation of technical efficiency requires the use of plant-level data for each of the five-digit KSIC industries available from the Census of Manufactures, one may consture the findings of this paper as empirical evidence of technical efficiency in Korea's manufacturing industries at the most disaggregated level. We start by clarifying the relationship among the various concepts of efficiency-allocative effciency, factor-price efficiency, technical efficiency, Leibenstein's X-efficiency, and scale efficiency. It then becomes clear that unless certain ceteris paribus assumptions are satisfied, our estimates of technical inefficiency are in fact related to factor price inefficiency as well. The empirical model employed is, what is called, a stochastic frontier production function which divides the stochastic term into two different components-one with a symmetric distribution for pure white noise and the other for technical inefficiency with an asymmetric distribution. A translog production function is assumed for the functional relationship between inputs and output, and was estimated by the corrected ordinary least squares method. The second and third sample moments of the regression residuals are then used to yield estimates of four different types of measures for technical (in) efficiency. The entire range of manufacturing industries can be divided into two groups, depending on whether or not the distribution of estimated regression residuals allows a successful estimation of technical efficiency. The regression equation employing value added as the dependent variable gives a greater number of "successful" industries than the one using gross output. The correlation among estimates of the different measures of efficiency appears to be high, while the estimates of efficiency based on different regression equations seem almost uncorrelated. Thus, in the subsequent analysis of the determinants of interindustry variations in technical efficiency, the choice of the regression equation in the previous stage will affect the outcome significantly.

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Impacts of R&D and Smallness of Scale on the Total Factor Productivity by Industry (R&D와 규모의 영세성이 산업별 총요소생산성에 미치는 영향)

  • Kim, Jung-Hwan;Lee, Dong-Ki;Lee, Bu-Hyung;Joo, Won
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.2 no.4
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    • pp.71-102
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    • 2007
  • There were many comprehensive analyses conducted within the existing research activities wherein factors affecting technology progress including investment in R&D vis-${\Box}$-vis their influences act as the determinants of TFP. Note, however, that there were few comprehensive analysis in the industrial research performed regarding the impact of the economy of scale as it affects TFP; most of these research studies dealt with the analysis of the non -parametric Malmquist productivity index or used the stochastic frontier production function models. No comprehensive analysis on the impacts of individual independent variables affecting TFP was performed. Therefore, this study obtained the TFP increase rate of each industry by analyzing the factors of the existing growth accounting equation and comprehensively analyzed the TFP determinants by constructing a comprehensive analysis model considering the investment in R&D and economy of scale (smallness by industry) as the influencers of TFP by industry. First, for the TFP increase rate of the 15 industries as a whole, the annual average increase rate for 1993${\sim}$ 1997 was approximately 3.8% only; during 1999${\sim}$ 2000 following the foreign exchange crisis, however, the annual increase rate rose to approximately 7.8%. By industry, the annual average increase rate of TFP between 1993 and 2000 stood at 11.6%, the highest in the electrical and electronic equipment manufacturing business and IT manufacturing sector. In contrast, a -0.4% increase rate was recorded in the furniture and other product manufacturing sectors. In the case of the service industry, the TFP increase rate was 7.3% in the transportation, warehousing, and communication sectors. This is much higher than the 2.9% posted in the electricity, water, and gas sectors and -3.7% recorded in the wholesale, food, and hotel businesses. The results of the comprehensive analysis conducted on the determinants of TFP showed that the correlations between R&D and TFP in general were positive (+) correlations whose significance has yet to be validated; in the model where the self-employed and unpaid family workers were used as proxy variables indicating the smallness of industry out of the total number of workers, however, significant negative (-) correlations were noted. On the other hand, the estimation factors of variables surrogating the smallness of scale in each industry showed that a consistently high "smallness of scale" in an industry means a decrease in the increase rate of TFP in the same industry.

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