UMYU Scientifica最新文献

{"title":"An Order Quantity Model for Delayed Deteriorating Items with Time-varying Demand Rate and Holding Cost, Complete Backlogging Rate and Two-level Pricing Strategies under Trade Credit Policy","authors":"Aisha Ahmed Madugu, B. Bature, Ibrahim M. Idris, Mustapha Malumfashi Lawal","doi":"10.56919/usci.2323.022","DOIUrl":"https://doi.org/10.56919/usci.2323.022","url":null,"abstract":"In some classical inventory models for non-instantaneous deteriorating items, it is tacitly assumed that the selling price before and after deterioration sets in is the same.  However, in real practice, when deterioration sets in, the retailer may decide to reduce the selling price to encourage more sales, reduce the cost of holding stock, attract new customers and reduce losses due to deterioration.  This research developed an economic order quantity model for non-instantaneous deteriorating items with two-phase demand rates, linear holding cost, complete backlogging rate and two-level pricing strategies under trade credit policy.  It is assumed that the holding cost is linear time-dependent, the unit selling price before deterioration sets in is greater than that after deterioration sets and the demand rate before deterioration sets in is considered as continuous time-dependent quadratic, after which it is considered as constant up to when the inventory is completely exhausted.  Shortages are allowed and completely backlogged.  The proposed model determines the optimal time with positive inventory, cycle length and order quantity such that the total profit of the inventory system has a maximum value.  The necessary and sufficient conditions for the existence and uniqueness of optimal solutions have been established.  Numerical experiments have been conducted to illustrate the theoretical result of the model.  Sensitivity analysis of some model parameters on the decision variables has been carried out, and suggestions towards maximising the total profit were also given.","PeriodicalId":506326,"journal":{"name":"UMYU Scientifica","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139332005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity, Composition and Economic Importance of Herbaceous Plants within the Federal Polytechnic Kaura Namoda Campus, Zamfara State, Nigeria.","authors":"Bello Musawa Bello, Khalid Tukur, Nura Salah Maiakwai, Mustapha Muhammad Sani, Mukhtar Abubakar Lawal","doi":"10.56919/usci.2322.014","DOIUrl":"https://doi.org/10.56919/usci.2322.014","url":null,"abstract":"The diversity, composition and economic importance of herbaceous species within the federal polytechnic Kaura Namoda, Zamfara State was studied.  The study's objective was to identify, document and evaluate the diversity and abundance of herbaceous species in the study area.  The point-centered quarter (PCQ) method was employed in each sampling point.  All nearest living herb species encountered were listed.  Data obtained were quantitatively analyzed for Relative density (RD) and relative frequency (RF).  Species diversity was calculated using Simpson’s index and the Shannon-Weiner index.  A total of 64 species of herb were identified belonging to 19 Families.  Acanthaceae, Aizoaceae, Cleomaceae, Connaraceae, Laminaceae, Oxalidaceae, and Plantaginaceae had (1) species each. Convolvulaceae, Cucurbitaceae and Euphobiaceae had (2) species each. Apocynaceae, Asteraceae, Malvaceae, Pedaliaceae and Poaceae had (3) species each. Solonaceae is the only family with (4) species.  Fabaceae is the only family with the highest number of species (32).  A total of 494 individuals of herbaceous species were in the study area. Site A has the highest number of individuals (117), followed by Site D (103), Site C (95) and E (82).  Tephrosia pedicellata has the highest species density of 3.2. Leptadenia hastata, Centaurea perrottetii, Gynandropsis gynandra, Euphorbia balsamifera, Senna obtusifolia, Abrus precatorius, Desmodium velutinum, Crotalaria goreensis, Crotalaria pallida var.obovata, Tephrosia pedicellata, Indigofera oblongifolia, Tephrosia vogelii, Tephrosia linearis, Biophytum petersianum, Sesamum radiatum, Solanum lycopersicum has the highest Frequency (100%). Senna tora has the highest relative abundance (5), and Euphorbia balsamifera has a Relative Density of 3.8.  Euphorbia balsamifera has the highest relative density of 5, and Ipomea asarifolia has an IVI of 7.  Shannon Weiner's diversity index for herbaceous species showed a total of 4.0097.  Herbaceous plants are of economic importance; they serve as food, fooder, medicine, fuel, and other purposes.  We recommended that there is a need for the conservation of herbaceous species within the Polytechnic to avoid harvesting the herbs for medicinal purposes and animals foraging on the grasses.","PeriodicalId":506326,"journal":{"name":"UMYU Scientifica","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139366323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}