scholarly journals A Detailed Examination of Sphicas (2014), Generalized EOQ Formula Using a New Parameter: Coefficient of Backorder Attractiveness

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 931 ◽  
Author(s):  
Luo
Keyword(s):  
Open Problem ◽  
Algebraic Method ◽  
Generalized Solution ◽  
Detailed Examination ◽  
Inventory Model ◽  
The Other ◽  
Inventory Models ◽  
Solution Approach ◽  
Feasible Domain ◽  
Parameter Coefficient

Researchers have used analytic methods (calculus) to solve inventory models with fixed and linear backorder costs. They have found conditions to partition the feasible domain into two parts. For one part, the system of the first partial derivatives has a solution. For the other part, the inventory model degenerates to the inventory model without shortages. A scholar tried to use the algebraic method to solve this kind of model. The scholar mentioned the partition of the feasible domain. However, other researchers cannot understand why the partition appears, even though the scholar provided two motivations for his derivations. After two other researchers provided their derivations by algebraic methods, the scholar showed a generalized solution to combine inventory models with and without shortages together. In this paper, we will point out that this generalized solution approach not only did not provide explanations for his previous partition but also contained twelve questionable results. Recently, an expert indicated questionable findings from two other researchers. Hence, we can claim that solving inventory models with fixed and linear backorder costs is still an open problem for future researchers.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

Multi-Location Inventory Model Considering Bidirectional and Unidirectional Transshipments Simultaneously

2013 ◽  
Vol 694-697 ◽  
pp. 2742-2745
Author(s):  
Jin Hong Zhong ◽  
Yun Zhou
Keyword(s):  
Process Model ◽  
Approximate Calculation ◽  
Inventory Model ◽  
Inventory System ◽  
Death Process ◽  
Birth And Death Process ◽  
Inventory Models ◽  
Continuous Review ◽  
Poisson Demand ◽  
Queue Theory

Abstract. A cross-regional multi-site inventory system with independent Poisson demand and continuous review (S-1,S) policy, in which there is bidirectional transshipment between the locations at the same area, and unidirectional transshipment between the locations at the different area. According to the M/G/S/S queue theory, birth and death process model and approximate calculation policy, we established inventory models respectively for the loss sales case and backorder case, and designed corresponding procedures to solve them. Finally, we verify the effectiveness of proposed models and methods by means of a lot of contrast experiments.

Resolving the Lourinia armata (Claus, 1866) complex with remarks on the monophyletic status of Louriniidae, Monard 1927 (Copepoda: Harpacticoida)

Zootaxa ◽  
2021 ◽  
Vol 5051 (1) ◽  
pp. 346-386
Author(s):  
SÜPHAN KARAYTUĞ ◽  
SERDAR SAK ◽  
ALP ALPER ◽  
SERDAR SÖNMEZ
Keyword(s):  
Comparative Evaluation ◽  
Species Complex ◽  
Detailed Examination ◽  
The Other ◽  
Phylogenetic Position ◽  
Nicobar Island ◽  
Other Hand ◽  
The Family ◽  
Close Relationship ◽  
Almost All

An attempt was made to test if Lourinia armata (Claus, 1866)—as it is currently diagnosed—represents a species complex. Detailed examination and comparisons of several specimens collected from different localities suggest that L. armata indeed represents a complex of four closely related morphospecies that can be differentiated from one another by only detailed observations. One of the four species is identified as Lourinia aff. armata and the other three species are described as new to science and named as Lourinia wellsi sp. nov., L. gocmeni sp. nov., and L. aldabraensis sp. nov. Detailed review of previous species records indicates that the genus Lourinia Wilson, 1924 is distributed worldwide. Ceyloniella nicobarica Sewell, 1940, originally described from Nicobar Island and previously considered a junior subjective synonym of L. armata is reinstated as Lourinia nicobarica (Sewell, 1940) comb. nov. on the basis of the unique paddle-shaped caudal ramus seta V. It is postulated that almost all of these records are unreliable in terms of representing true Lourinia aff. armata described herein. On the other hand, the comparative evaluation of the illustrations and descriptions in the published literature indicates the presence of several new species waiting to be discovered in the genus Lourinia.                 It has been determined that, according to updated modern keys, the recent inclusion of the monotypic genus Archeolourinia Corgosinho & Schizas, 2013 in the Louriniidae is not justified since Archeolourinia shermani Corgosinho & Schizas, 2013 does not belong to this family but should be assigned to the Canthocamptidae. On the other hand, it has been argued that the exact phylogenetic position of the Louriniidae still remains problematic since none of the diagnostic characters supports the monophyly of the family within the Oligoarthra. It has also been argued that the close relationship between Louriniidae and Canthocamptidae is supported since both families share the homologous sexual dimorphism (apophysis) on P3 endopod. The most important characteristic that can possibly be used to define Louriniidae is the reduction of maxilliped.  

Attitudes to reform: political parties in Ulster and the Irish land bill of 1881

1985 ◽  
Vol 24 (95) ◽  
pp. 327-340
Author(s):  
Francis Thompson
Keyword(s):  
Political Parties ◽  
Detailed Examination ◽  
The Other ◽  
The South ◽  
The North ◽  
Other Hand ◽  
Previous Decade ◽  
History Of

The Irish land act of 1881, it is generally agreed, was a victory for the Land League and Parnell, and nationalist policy with regard to the act and the attitude of southern tenants towards it have been many times subjected to detailed examination by historians of this period. In these analyses of the events of 1880–81, however, little reference is normally made to the part played by the different parties and interests in the north of the country. It is often assumed, for example, that the Ulster tenants held aloof from the campaign for reform, lending no more than occasional vocal support to the agitational efforts of tenants in the south and west. Indeed, they were later excoriated by William O'Brien, Michael Davitt and others not only for giving no support to the land movement but also for sabotaging Parnell's policy of testing the 1881 act by precipitately rushing into the land courts to take advantage of the new legislation: ‘that hard-fisted body of men, having done nothing themselves to win the act, thought of nothing but turning it to their own immediate use, and repudiating any solidarity with the southern and western rebels to whom they really owed it’. If, however, northern tenants were harshly judged by nationalist politicians in the years after 1881, the part played by the northern political parties in the history of the land bill has been either ignored or misunderstood by historians since that time. The Ulster liberals, for example, are rarely mentioned, the implication being that they made no contribution to the act even though it implemented almost exactly the programme on which they had been campaigning for much of the previous decade. The northern conservatives, on the other hand, are commonly seen as leading opponents of the bill, more intransigent than their party colleagues in the south, ‘quick to denounce any weakening of the opposition’ to reform, and ‘determined to keep the tory party up to the mark in defending the landlord interest’

An Imperfect Production Model for Breakable Multi-Item with Dynamic Demand and Learning Effect on Rework over Random Planning Horizon

2021 ◽  
Vol 14 (12) ◽  
pp. 574
Author(s):  
Amalesh Kumar Manna ◽  
Leopoldo Eduardo Cárdenas-Barrón ◽  
Barun Das ◽  
Ali Akbar Shaikh ◽  
Armando Céspedes-Mota ◽  
...  
Keyword(s):  
Learning Effect ◽  
Planning Horizon ◽  
Inventory Model ◽  
Inventory System ◽  
Production Model ◽  
Inventory Models ◽  
Imperfect Production ◽  
Production Inventory ◽  
Random Planning Horizon ◽  
Production Inventory System

In recent times, in the literature of inventory management there exists a notorious interest in production-inventory models focused on imperfect production processes with a deterministic time horizon. Nevertheless, it is well-known that there is a high influence and impact caused by the learning effect on the production-inventory models in the random planning horizon. This research work formulates a mathematical model for a re-workable multi-item production-inventory system, in which the demand of the items depends on the accessible stock and selling revenue. The production-inventory model allows shortages and these are partial backlogged over a random planning horizon. Also, the learning effect on the rework policy, inflation, and the time value of money are considered. The main aim is to determine the optimum production rates that minimize the expected total cost of the multi-item production-inventory system. A numerical example is solved and a detailed sensitivity analysis is conducted in order to study the production-inventory model.

A Deterministic Inventory Model under Quantity-depended Payments Delay Policy Using Algebraic Method

2006 ◽  
Vol 6 (2) ◽  
pp. 406-410 ◽  
Author(s):  
Chih-Sung Lai ◽  
Yung-Fu Huang . ◽  
Hung-Fu Huang .
Keyword(s):  
Algebraic Method ◽  
Inventory Model

scholarly journals Generating Adjoint Groups

2019 ◽  
Vol 62 (3) ◽  
pp. 733-738 ◽  
Author(s):  
Be'eri Greenfeld
Keyword(s):  
Open Problem ◽  
Jacobson Radical ◽  
The Other ◽  
Adjoint Group ◽  
Finitely Generated ◽  
Infinite Dimensional ◽  
Other Hand ◽  
Nil Ring

AbstractWe prove two approximations of the open problem of whether the adjoint group of a non-nilpotent nil ring can be finitely generated. We show that the adjoint group of a non-nilpotent Jacobson radical cannot be boundedly generated and, on the other hand, construct a finitely generated, infinite-dimensional nil algebra whose adjoint group is generated by elements of bounded torsion.

Kodály's Melody

Tempo ◽  
1963 ◽  
pp. 12-16
Author(s):  
András Szőllősy
Keyword(s):  
Chamber Music ◽  
Folk Music ◽  
Close Contact ◽  
Detailed Examination ◽  
Folk Song ◽  
The Other ◽  
Organic Part ◽  
Violin And Piano ◽  
Shed Light

It is a generally accepted view that the most striking features of Kodály's melodic structure may be explained by the influence of folk song. This is not borne out, however, by more detailed examination. It is true that there are certain features in his melodic types which later undergo a change, and of these a prime example is the precise periodic articulation of the melodies, which is much more consistent in his later compositions than in those of his youth. Such characteristics may indeed be attributed to the influence of folk music, but in general the typical Kodály melody existed before he could have come into close contact with folk music in the year when he made his first folk song collecting trip. Of his compositions from the years 1904–1906, the only work we can consider from the viewpoint of melodic structure is the ‘Adagio’ for violin and piano; the other two compositions, Evening for mixed voice choirs and Summer Evening for orchestra, are known only in their later revised form of 1930. This, however, is sufficient to convince us that the expansive declamation and the structural ornamentation which is an organic part of its idiom continue an instrumental tradition whose origin may well go back to chamber music of the Baroque age, with its broad-flowing slow movements. This also seems to be substantiated by the piano part, which replaces impressionistic harmonies with those which may be analysed in accordance with classical harmonic principles. This characteristic harmonisation requires mention here, although it is not closely connected with the problem of melodic structure, since even the most complicated of Kodály's harmonies, when stripped of their embellishments, reveal pure ‘classical’ chords as their basis. The role of the melody in this problem serves merely to emphasise that with Kodály, perhaps more than any other composer, harmony is never an end in itself, but is always the result of the movement of the melody. If the word did not have more significance than we wish to attribute to it here, we might say that Kodály's harmony is only secondary to melody. This word ‘secondary’, however, does not refer to expression, but merely attempts to shed light on the matter of origin, by stressing the supreme importance of melody for Kodály.

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