352 research outputs found

    ν•œκ΅­μ‚° λ‚˜λ¬΄μ’€μ•„κ³Όμ™€ κΈ΄λ‚˜λ¬΄μ’€μ•„κ³Ό (λ”±μ •λ²Œλ ˆλͺ©: 바ꡬ미과)의 λΆ„λ₯˜ν•™μ  연ꡬ

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    ν•™μœ„λ…Όλ¬Έ (박사)-- μ„œμšΈλŒ€ν•™κ΅ λŒ€ν•™μ› : 농생λͺ…곡학뢀, 2016. 8. μ΄μŠΉν™˜.This paper consisted of two main results. First one is concerned on a taxonomic review on the Korean Scolytinae and Platypodinae through the re-examination of Korean specimens preserved in the several institutes. Secondly, I examined the taxonomic status of these two subfamilies, identified undetermined species, and placed newly recognized species into the adequate genera using DNA barcodes analysis. I adopted the higher classification system of the Catalogue of Palaearctic Coleoptera edited by Lobl and Smetana (2011) and modified several generic groups because some generic positions are changed after recent studies (Hulcr and Cognato, 2013). In this results, I discussed the changes of phylogenetic status of Scolytinae and Platypodinae. In fact, these two subfamilies of Scolytinae and Platypodinae are still in the center of controversy about their taxonomic positions. Some taxonomists still prefer to consider the two subfamilies as valid families. In this study, 4 new species and 10 newly recorded species to the Korean fauna were found. And Scolytoplatypus sinensis, which was synonymised with S. mikado resurrected as a valid species after examining the DNA barcodes and morphological characters. Two species belong to Xyleborus transferred to the genus Cyclorhipidon after examining the DNA barcode and morphological characters. New species and newly added species to Korean fauna are as follows: Hylurgus ligniperda (Fabricius, 1787) new to Korea Tomicus heuksandoensis sp. nov. new to Science Sueus niisimai (Eggers, 1926) new to Korea Hypothenemus expers Blandford, 1894 new to Korea Scolytoplatypus sinensis Tsai & Huang, 1965 new to Korea, resurrected Cyclorhipidion japonicus (Nobuchi, 1981) comb. nov., new to Korea Cyclorhipidion laetus Niisima, 1909 comb. nov., new to Korea Cyclorhipidion pseudopelliculosum sp. nov. new to Science Xyleborinus kwangreungensis sp. nov. new to Science Xyleborus glabratus Eichhoff, 1876 new to Korea Xyleborus muticus Blandford, 1894 new to Korea Xylosandrus compactus (Eichhoff, 1876) new to Korea Xylosandrus pseudogermanus sp. nov. new to Science Dinoplatypus hamatus (Blandford, 1894) new to Korea Totally, 261 COI sequences of the 109 Scolytinae and Platypodinae species were analyzed in this study. Several tribal groups are clearly divided into separated branches and show monophyletic aspects. For examples, tribe Ipini, Scolytini, Scolytoplatypodini, and Xyloterini are clearly divided each others. In case of tribe Xyleborini, they show almost independent tree from other tribes except containing some species in genus Coccotrypes of tribe Dryocoetini. Tribe Hylastini and Hylurgini also clearly divided into separated monophyletic groups in the level of tribes and genera. Despite of those many efforts on the phylogeny, of the higher classification of the family Curculionidae and the rank of the subfamily Scolytinae and Platypodinae, are still debated and unresolved. To solve the problems on the phylogenetic position of these two groups, additional studies using the both of morphological and molecular methods are required. Many generic and species groups in both subfamilies are still not well-positioned in the classification. Therefore, the phylogenetic studies of the higher category classification should apparently be accompanied with the re-arrangements on unclear generic and species positions.I. INTRODUCTION OF THE SUBFAMILY SCOLYTINAE AND PLATYPODINAE 1 1. General introduction of the subfamily Scolytinae and Platypodinae 1 2. Historical Review of Scolytinae and Platypodinae in Korea 8 3. Contents of the review of Scolytinae and Platypodinae in Korea 10 II. MATERIALS AND METHODS 11 1. Materials examined 11 2. Illustrations of species 12 3 Abbreviations of provinces in the Korean Peninsula 12 4. Terminology 13 5. DNA sequencing from nondestructive methods and selection of genetic markers 15 6. Data analysis 15 III. RESULTS 17 1. Taxonomic review of Scolytinae and Platypodinae in Korea 17 2. DNA barcodes in the examined species of the subfamily Scolytinae and Platypodinae 269 IV. DISCUSSION 280 1. Taxonomic review of Korean Scolytinae and Platypodinae 280 2. DNA barcodes in the examined species of Scolytinae and Platypodinae 283 3. Taxonomic status of Scolytinae and Platypodinae 285 LITERATURE CITED 289 PLATE 295 κ΅­λ¬Έ 초둝 332Docto

    Cost Effectiveness of Postponed Routing Decisions in a Supply Chain

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    This paper examines the cost-reduction effect of postponed routing decisions in a two-echelon supply chain. When a delivery vehicle leaves the warehouse with system replenishment quantities, it sequentially makes routing decisions to choose the next retailer to visit. To measure this effect this paper studies combined vehicle routing and inventoryallocation policies designed to minimize total expected purchasing, inventory-holding and backordering cost/period for a one-warehouse Nretailer symmetric distribution system. Using a numerical study, we demonstrate that optimal dynamic routing and allocation policies can significantly reduce the inventory-management costs associated with fixed routing and dynamic allocation in medium-to-large customer demand-variance scenarios

    Risk-Pooling Effects of Emergency Shippping in a Two-Echelon Distribution System

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    This paper analyzes the optimal replenishment policy in a one warehouse N-retailer distribution system operating in a periodic-review mode where emergency shipping from a central warehouse or a retailer to an individual customer is allowed to satisfy retailer backorders at the end of the cycle. We show that, under the assumption that it costs the same whether emergency shipping is made by the warehouse or by a retailer, it is optimal that the warehouse carries no inventory. Under the same assumption, the form of the optimal system-replenishment policy is shown to be a base-stock policy, and the necessary and sufficient condition of optimality, which is analogous to that of the Newsboy problem, is presented. The further analysis shows that, with emergency shipping allowed, the warehouse orders less from its supplier.This paper analyzes the optimal replenishment policy in a one warehouse N-retailer distribution system operating in a periodic-review mode where emergency shipping from a central warehouse or a retailer to an individual customer is allowed to satisfy retailer backorders at the end of the cycle. We show that, under the assumption that it costs the same whether emergency shipping is made by the warehouse or by a retailer, it is optimal that the warehouse carries no inventory. Under the same assumption, the form of the optimal system-replenishment policy is shown to be a base-stock policy, and the necessary and sufficient condition of optimality, which is analogous to that of the Newsboy problem, is presented. The further analysis shows that, with emergency shipping allowed, the warehouse orders less from its supplier

    Routing and Inventory Allocation Policies in Multi-Echelon Distribution Systems

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    This paper reviews the previous research in the area of logistics systems, especially in the area of the multi-echelon distribution system with stochastic demand. Many researches in this area emphasize the value of real-time information (which is more readily available nowadays by use of EDS or satellite systems) in distribution-related decisions. Also a great deal of efforts has been taken to study the risk-pooling effect of the various distribution policies in the multi-echelon systems. The objectives of this review are two-folded; (1) to help readers to understand the research paradigm in the multi-echelon area, and (2) to help them to find future research topics not yet explored
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