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Analytical Insight (analytical + insight)
Selected AbstractsScheduling Part-Families Under FMS: To Mix or Not to Mix?INTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 2 2001Henry C. Co This paper considers the issue of whether to mix part-types in one or several of the families to be produced in a flexible manufacturing system (FMS). For this input control problem in an FMS, we have derived conditions that support the mixing of a part-type, which can share the setup of other part-types, in deterministic environment. The problem is identified as a special economic lot scheduling problem (ELSP), and is formulated as a linear programming problem. Analytical insights are derived by considering the special case with three part-families. The results are illustrated with a numerical example. [source] Recognition of resonance in long radial transmission lines with static VAR compensation using travelling wavesEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 1 2005Ljubivoje M. Popovi Abstract This paper presents an analytical procedure for estimation of resonance frequencies in long-distance radial transmission lines with static VAR compensation. The development of the procedure is based on a new approach in solving this problem. It employs the fact that the phenomenon is characterized by an algebraic sum of travelling current waves at the beginning of the line. Relatively simple analytical expressions are obtained by considering the phase angles of only one direct and only one corresponding reflected wave. Besides enabling a simpler and faster solution of the problem under various realistic conditions, the obtained analytical expressions also offer more direct analytical insight into the interplay of basic parameters. Copyright © 2005 John Wiley & Sons, Ltd. [source] The local theory of the cosmic skeletonMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2009D. Pogosyan ABSTRACT The local theory of the critical lines of two- and three-dimensional random fields that underline the cosmic structures is presented. In the context of cosmological matter distribution, the subset of critical lines of the three-dimensional density field serves to delineate the skeleton of the observed filamentary structure at large scales. A stiff approximation used to quantitatively describe the filamentary skeleton shows that the flux of the skeleton lines is related to the average Gaussian curvature of the (N , 1) dimensional sections of the field. The distribution of the length of the critical lines with threshold is analysed in detail, while the extended descriptors of the skeleton , its curvature and singular points , are introduced and briefly described. Theoretical predictions are compared to measurements of the skeleton in realizations of Gaussian random fields in two and three dimensions. It is found that the stiff approximation accurately predicts the shape of the differential length, allows for analytical insight and explicit closed form solutions. Finally, it provides a simple classification of the singular points of the critical lines: (i) critical points; (ii) bifurcation points and (iii) slopping plateaux. [source] Lessons from the Past: The First Wave of Developmental Assistance to North Korea and the German Reconstruction of HamhùngPACIFIC FOCUS, Issue 1 2008Rüdiger Frank North Korea is currently a receiver of substantial international economic support, but not for the first time in its history. This article seeks to shed some light on a largely unknown instance of multilateral aid and assistance to North Korea provided by the socialist camp in the 1950s. Based on research in archives and the analysis of trade data and contemporary media reports, the focus is mainly on the contribution of East Germany to the reconstruction of the North Korean city of Hamhùng. It is argued that this relatively well documented and completed case provides a number of highly relevant conclusions for the current, ongoing debate on engagement with North Korea. Comparing two historically distinct "waves" of assistance to the same country provides new analytical insights if contrasted with the usual approach of using assistance to a third country as the point of reference. There is evidence that North Korea might be applying the same tactics as five decades ago, while the international community faces the danger of repeating old mistakes. Moreover, history provides a hitherto underestimated rationale for the nuclear program, one that might require the international community to develop very different strategies from the ones applied so far. [source] Industry Clockspeed and the Pace of New Product DevelopmentPRODUCTION AND OPERATIONS MANAGEMENT, Issue 2 2005Janice E. Carrillo Recent empirical literature describes an industry's clockspeed as a measure of the evolutionary life cycle, which captures the dynamic nature of the industry. Among other factors, the rate of new product development is found to be associated with an industry's clockspeed. Yet the notion of an industry clockspeed and the essential factors driving suitable decision making in this area have remained relatively unexplored. We develop a simple definition and a corresponding analytic model which explains the interdependent relationship between a firm's own new product development activities and an industry clockspeed. Results from the single firm model show the conditions under which particular firms have an incentive to accelerate their new product development activities. Moreover, we link the single firm's NPD clockspeed decisions to the industry level by creating appropriate metrics which characterize different types of industries. Examples from high-tech industries such as the personal computer and aerospace industries are included to illustrate our findings. Our intention is not only to offer analytical insights into factors driving the clockspeed for these industries, but also to establish a fundamental structured decision making approach, thereby stimulating future research on this important topic. [source] | ||||||||||