Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

DEFF Research Database (Denmark)

Johansen, Søren Glud; Thorstenson, Anders

2008-01-01

We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the 'extended lead time'. The derived performance measures...

Note: Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

DEFF Research Database (Denmark)

Johansen, Søren Glud; Thorstenson, Anders

We show that well-known textbook formulae for determining the optimal base stock of the inventory system with continuous review and constant lead time can easily be extended to the case with periodic review and stochastic, sequential lead times. The provided performance measures and conditions...

Improvement of inventory control and forecast according to activity-based classifications: T company as an example

Science.gov (United States)

Huang, Jui-Chan; Wu, Tzu-Jung; Chiu, Yen-Chun; Lu, Chunwei

2017-06-01

Inventory management is a major issue for all the industries. The supply of products to customers requires the readiness of the inventory. This allows rapid delivery and reduces waiting time for customers so that companies can profit from it. Any stock out or insufficiency will lead to loss of customers because their needs cannot be met. This will hurt firm profitability and market competitiveness. Inventory control is critical to retain liquidity and avoid overstocking. This is also the key to firm's survival and sustainability. To ensure an appropriate level of inventory, it is necessary to manage the inventory levels with sales forecast on an on-going basis. This paper seeks to assist Company T to improve its inventory control. Firstly, the products offered by Company T are classified into groups. The R programming language is used to stimulate and forecast future sales of different products. Different techniques are applied to manage the inventory levels according to the results of categorizations and forecasts that are consolidation of all the product items and grouping them into activity-based classifications, simulation and forecasting of future sales according to the categorization results, and formulation of different control techniques based on the simulations and forecasts. The results and the inventory management can be used to enhance the inventory control as well.

Dynamic Pricing and Production Control of an Inventory System with Remanufacturing

Directory of Open Access Journals (Sweden)

Chunyan Gao

2015-01-01

Full Text Available We consider optimal pricing and manufacturing control of a continuous-review inventory system with remanufacturing. Customer demand and product return follow independent Poisson processes. Customer demand is filled by serviceable product, which can be either manufactured or remanufactured from the returned product. The lead times for both manufacturing and remanufacturing are exponentially distributed. The objective is to maximize the expected total discounted profit over an infinite planning horizon. We characterize the structural properties of the optimal policy through the optimality equation. Specifically, the optimal manufacturing policy is a base-stock policy with the base-stock level nonincreasing in the return inventory level. The optimal pricing policy is also a threshold policy, where the threshold level is nonincreasing in the return inventory level.

Optimization Policy of Inventory Spare Parts Stocking and Provisioning

International Nuclear Information System (INIS)

Yun, Tae Sik; Park, Jong Hyuk; Hwang, Eui Youp; Yoo, Sung Soo; Kim, In Hwan

2005-01-01

Spare parts, especially safety related items, being used in Korea Nuclear Power Plants are largely from the United States, Canada, France and the like, meaning the inventory policy, stocking and provision, should be influenced by those countries' nuclear industry situation in a direct or indirect manner. As a result of nuclear industry downturn practices, lots of spare supply corporations have gone broke, which gave immediate signals we have to resolve inventory purchases in need. It is known for that nuclear maintenance spare items are particularly composed of many kinds with small quantities, which makes matters worse to Korea nuclear operation company (KHNP) to purchase them. Hence, Korea nuclear business is trying to change its exinventory purchasing paradigm into innovative schemes it did not have to consider in the past. In order to implement a new stocking policy, it should be kept in mind the factors such as not only how much to stock for a smooth operation but also economic point of view. Even though it has done a lot of studies to optimize the inventory stocking level in an academic curiosity, it is not easy to apply the researches in a real world. Since it is so tough job to anticipate when and how large scale even occurs. Hence, it would be thought that the nuclear inventory should be dealt in a different manner from the general manufacturing industry

Joint inventory control and pricing in a service-inventory system

DEFF Research Database (Denmark)

Marand, Ata Jalili; Li, Hongyan Jenny; Thorstenson, Anders

2017-01-01

This study addresses joint inventory control and pricing decisions for a service-inventory system. In such a system both an on-hand inventory item and a positive service time are required to fulfill customer demands. The service-inventory system also captures main features of the classical...... inventory systems with a positive processing time, e.g., make-to-order systems. In this study, the service-inventory system is modeled as an M/M/1 queue in which the customer arrival rate is price dependent. The inventory of an individual item is continuously reviewed under an (r,Q) policy....... The replenishment lead times of the inventory are exponentially distributed. Furthermore, customers arriving during stock-out periods are lost. The stochastic customer inter-arrival times, service times, and inventory replenishment lead times cause the high complexity of the problem and the difficulty in solving it...

Base stock system for patient vs impatient customers with varying demand distribution

Science.gov (United States)

Fathima, Dowlath; Uduman, P. Sheik

2013-09-01

An optimal Base-Stock inventory policy for Patient and Impatient Customers using finite-horizon models is examined. The Base stock system for Patient and Impatient customers is a different type of inventory policy. In case of the model I, Base stock for Patient customer case is evaluated using the Truncated Exponential Distribution. The model II involves the study of Base-stock inventory policies for Impatient customer. A study on these systems reveals that the Customers wait until the arrival of the next order or the customers leaves the system which leads to lost sale. In both the models demand during the period [0, t] is taken to be a random variable. In this paper, Truncated Exponential Distribution satisfies the Base stock policy for the patient customer as a continuous model. So far the Base stock for Impatient Customers leaded to a discrete case but, in this paper we have modeled this condition into a continuous case. We justify this approach mathematically and also numerically.

The Impact of Inventory Management on Stock-Outs of Essential Drugs in Sub-Saharan Africa: Secondary Analysis of a Field Experiment in Zambia.

Science.gov (United States)

Leung, Ngai-Hang Z; Chen, Ana; Yadav, Prashant; Gallien, Jérémie

2016-01-01

To characterize the impact of widespread inventory management policies on stock-outs of essential drugs in Zambia's health clinics and develop related recommendations. Daily clinic storeroom stock levels of artemether-lumefantrine (AL) products in 2009-2010 were captured in 145 facilities through photography and manual transcription of paper forms, then used to determine historical stock-out levels and estimate demand patterns. Delivery lead-times and estimates of monthly facility accessibility were obtained through worker surveys. A simulation model was constructed and validated for predictive accuracy against historical stock-outs, then used to evaluate various changes potentially affecting product availability. While almost no stock-outs of AL products were observed during Q4 2009 consistent with primary analysis, up to 30% of surveyed facilities stocked out of some AL product during Q1 2010 despite ample inventory being simultaneously available at the national warehouse. Simulation experiments closely reproduced these results and linked them to the use of average past monthly issues and failure to capture lead-time variability in current inventory control policies. Several inventory policy enhancements currently recommended by USAID | DELIVER were found to have limited impact on product availability. Inventory control policies widely recommended and used for distributing medicines in sub-Saharan Africa directly account for a substantial fraction of stock-outs observed in common situations involving demand seasonality and facility access interruptions. Developing central capabilities in peripheral demand forecasting and inventory control is critical. More rigorous independent peer-reviewed research on pharmaceutical supply chain management in low-income countries is needed.

On Inventory Control For Perishable Inventory Systems Subject To Uncertainties On Customer Demands

OpenAIRE

Abbou , Rosa; Loiseau , Jean-Jacques; Khaldi , Hajer; Farraa , Berna ,

2017-01-01

International audience; This paper deals with the inventory controller design for constrained production systems subject to uncertainties on the customer demands. The case study focuses on the inventory regulation problem in production systems where contain perishable finite products. Such systems are characterized by the presence of delays due to production processes, and constraints from the instantaneous inventory level, production level and the finite capacities of stocks. To do that, we ...

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2011-01-01

This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level...... measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...

Oil inventories should be based on margins, supply reliability

International Nuclear Information System (INIS)

Waguespack, K.; Cantor, B.D.

1996-01-01

US oil inventories have plummeted to their lowest recorded levels this year, leading industry observers to conclude that refiners have adopted new just-in-time (JIT) inventory policies. Total crude oil inventories are about 300 million bbl -- 8% below the 10-year average. Distillate inventories posted similar declines this year because of unusually cold winter temperatures and refiners' reluctance to build sufficient stocks in the autumn months. Gasoline stocks are 20% below the 10-year average at 200 million bbl, despite forecasts of record-high gasoline demand this summer. The sudden drop in crude and product inventories this year is widely considered a sign that refiners have implemented JIT, signaling a permanent shift to reduced stocks. The authors submit that the shift towards reduced oil inventories is not related to a concerted adoption of JIT by US refiners, and that oil inventory management decisions should instead be based on refining margins and supply reliability. The paper discusses the JIT revolution and the optimal-inventory model

Changing an automated drug inventory control system to a data base design.

Science.gov (United States)

Bradish, R A

1982-09-01

A pharmacy department's change from indexed sequential access files to a data base management system (DBMS) for purposes of automated inventory control is described. The DBMS has three main functional areas: (1) inventory ordering and accountability, (2) charging of interdepartmental and intradepartmental orders, and (3) data manipulation with report design for management control. There are seven files directly related to the inventory ordering and accountability area. Each record can be accessed directly or through another file. Information on the quantity of a drug on hand, drug(s) supplied by a specific vendor, status of a purchase order, or calculation of an estimated order quantity can be retrieved quickly. In the drug master file, two records contain a reorder point and safety-stock level that are determined by searching the entries in the order history file and vendor master file. The intradepartmental and interdepartmental orders section contains five files assigned to record and store information on drug distribution. All items removed from the stockroom and distributed are recorded, and reports can be generated for itemized bills, total cost by area, and as formatted files for the accounts payable department. The design, development, and implementation of the DBMS took approximately a year using a part-time pharmacist and minimal outside help, while the previous system required constant expensive help of a programmer/analyst. The DBMS has given the pharmacy department a flexible inventory management system with increased drug control, decreased operating expenses, increased use of department personnel, and the ability to develop and enhance other systems.

Base Stock Policy in a Join-Type Production Line with Advanced Demand Information

Science.gov (United States)

Hiraiwa, Mikihiko; Tsubouchi, Satoshi; Nakade, Koichi

Production control such as the base stock policy, the kanban policy and the constant work-in-process policy in a serial production line has been studied by many researchers. Production lines, however, usually have fork-type, join-type or network-type figures. In addition, in most previous studies on production control, a finished product is required at the same time as arrival of demand at the system. Demand information is, however, informed before due date in practice. In this paper a join-type (assembly) production line under base stock control with advanced demand information in discrete time is analyzed. The recursive equations for the work-in-process are derived. The heuristic algorithm for finding appropriate base stock levels of all machines at short time is proposed and the effect of advanced demand information is examined by simulation with the proposed algorithm. It is shown that the inventory cost can decreases with little backlogs by using the appropriate amount of demand information and setting appropriate base stock levels.

An Inventory and Safety Stock Analysis of Air Force Medical Service Pharmaceuticals

Science.gov (United States)

2015-03-26

wellbeing of a patient in need. Although stockouts of blood units typically pose a more immediate threat to the health of patients in need, the impact of...regarding the dissemination of the flu vaccinations to civilian employees of the base who are not covered by TRICARE. o An inventory and safety stock

Sistem kontrol inventori pemasokan barang Secara Real Time Menggunakan Vendor-Managed Inventory (VMI dan Short Message Service (SMS

Directory of Open Access Journals (Sweden)

Rinaldo Turang

2016-01-01

Full Text Available This research underlines the urgency of real-time stock replenishment control system for distributors using vendor-managed inventory. It is valuable in improving corporate performance in lowering inventory cost as well as making better customer service due to the cut made in ordering cycle. The system produces real-time information on stock available at the retailing stores. Stock replenishment can then be done by the distributor at the right time. Using Short Message Service (SMS as a one-way information channel from retailers to their distributor, the data of every transaction of the supervised item are processed by a rule-based forward-chaining inference system to determine the item’s availability in stores. Folowing steps in Rapid Application Development (RAD, the construction of this system takes place through business modeling, data modeling, process modeling of VMI system, then the application is generated and tested as a prototype. The results are: the stock replenishment control system are able to make transactional data at the stores transparent to the distributor, facilitating the continuation in stock delivery. System architecture reduces the time needed to access information about sales on supervised item by using SMS shortcut. This control system developed in stores can be operationally independent from the retailing systems. Rule-based forward-chaining inference technique processes facts on stock variations, resulting in stock replenishment notification such as normal, reserve, and depleted warning. Keywords: VMI, inventory; Stock replenishment; Rule-based reasoning; Forward-chaining system, RAD

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2014-01-01

This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total demanded quantity the order fill rate would be the preferred service...... level measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...... extensions consider more general inventory control review policies with backordering, as well as some relations between service measures. A particularly important result in the paper concerns an alternative service measure, the customer order fill rate, and shows how this measure always exceeds the other two...

The Role of Hybrid Make-to-Stock (MTS) - Make-to-Order (MTO) and Economic Order Quantity (EOQ) Inventory Control Models in Food and Beverage Processing Industry

Science.gov (United States)

Najhan Mohd Nagib, Ahmad; Naufal Adnan, Ahmad; Ismail, Azianti; Halim, Nurul Hayati Abdul; Syuhadah Khusaini, Nurul

2016-11-01

The inventory model had been utilized since the early 1900s. The implementation of the inventory management model is generally to ensure that an organisation is able to fulfil customer's demand at the lowest possible cost to improve profitability. This paper focuses on reviewing previous published papers regarding inventory control model mainly in the food and beverage processing industry. The author discusses four inventory models, which are the make-to-stock (MTS), make-to-order (MTO), economic order quantity (EOQ), and hybrid of MTS-MTO models. The issues raised by the researchers on the above techniques as well as the elements need to be considered upon selection have been discussed in this paper. The main objective of the study is to highlight the important role played by these inventory control models in the food and beverage processing industry.

Exploiting Growing Stock Volume Maps for Large Scale Forest Resource Assessment: Cross-Comparisons of ASAR- and PALSAR-Based GSV Estimates with Forest Inventory in Central Siberia

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Christian Hüttich

2014-07-01

Full Text Available Growing stock volume is an important biophysical parameter describing the state and dynamics of the Boreal zone. Validation of growing stock volume (GSV maps based on satellite remote sensing is challenging due to the lack of consistent ground reference data. The monitoring and assessment of the remote Russian forest resources of Siberia can only be done by integrating remote sensing techniques and interdisciplinary collaboration. In this paper, we assess the information content of GSV estimates in Central Siberian forests obtained at 25 m from ALOS-PALSAR and 1 km from ENVISAT-ASAR backscatter data. The estimates have been cross-compared with respect to forest inventory data showing 34% relative RMSE for the ASAR-based GSV retrievals and 39.4% for the PALSAR-based estimates of GSV. Fragmentation analyses using a MODIS-based land cover dataset revealed an increase of retrieval error with increasing fragmentation of the landscape. Cross-comparisons of multiple SAR-based GSV estimates helped to detect inconsistencies in the forest inventory data and can support an update of outdated forest inventory stands.

ECONOMIC MODELING STOCKS CONTROL SYSTEM: SIMULATION MODEL

OpenAIRE

Климак, М.С.; Войтко, С.В.

2016-01-01

Considered theoretical and applied aspects of the development of simulation models to predictthe optimal development and production systems that create tangible products andservices. It isproved that theprocessof inventory control needs of economicandmathematical modeling in viewof thecomplexity of theoretical studies. A simulation model of stocks control that allows make managementdecisions with production logistics

Relevance of carbon stocks of marine sediments for national greenhouse gas inventories of maritime nations.

Science.gov (United States)

Avelar, Silvania; van der Voort, Tessa S; Eglinton, Timothy I

2017-12-01

Determining national carbon stocks is essential in the framework of ongoing climate change mitigation actions. Presently, assessment of carbon stocks in the context of greenhouse gas (GHG)-reporting on a nation-by-nation basis focuses on the terrestrial realm, i.e., carbon held in living plant biomass and soils, and on potential changes in these stocks in response to anthropogenic activities. However, while the ocean and underlying sediments store substantial quantities of carbon, this pool is presently not considered in the context of national inventories. The ongoing disturbances to both terrestrial and marine ecosystems as a consequence of food production, pollution, climate change and other factors, as well as alteration of linkages and C-exchange between continental and oceanic realms, highlight the need for a better understanding of the quantity and vulnerability of carbon stocks in both systems. We present a preliminary comparison of the stocks of organic carbon held in continental margin sediments within the Exclusive Economic Zone of maritime nations with those in their soils. Our study focuses on Namibia, where there is a wealth of marine sediment data, and draws comparisons with sediment data from two other countries with different characteristics, which are Pakistan and the United Kingdom. Results indicate that marine sediment carbon stocks in maritime nations can be similar in magnitude to those of soils. Therefore, if human activities in these areas are managed, carbon stocks in the oceanic realm-particularly over continental margins-could be considered as part of national GHG inventories. This study shows that marine sediment organic carbon stocks can be equal in size or exceed terrestrial carbon stocks of maritime nations. This provides motivation both for improved assessment of sedimentary carbon inventories and for reevaluation of the way that carbon stocks are assessed and valued. The latter carries potential implications for the management of

Relevance of carbon stocks of marine sediments for national greenhouse gas inventories of maritime nations

Directory of Open Access Journals (Sweden)

Silvania Avelar

2017-05-01

Full Text Available Abstract Background Determining national carbon stocks is essential in the framework of ongoing climate change mitigation actions. Presently, assessment of carbon stocks in the context of greenhouse gas (GHG-reporting on a nation-by-nation basis focuses on the terrestrial realm, i.e., carbon held in living plant biomass and soils, and on potential changes in these stocks in response to anthropogenic activities. However, while the ocean and underlying sediments store substantial quantities of carbon, this pool is presently not considered in the context of national inventories. The ongoing disturbances to both terrestrial and marine ecosystems as a consequence of food production, pollution, climate change and other factors, as well as alteration of linkages and C-exchange between continental and oceanic realms, highlight the need for a better understanding of the quantity and vulnerability of carbon stocks in both systems. We present a preliminary comparison of the stocks of organic carbon held in continental margin sediments within the Exclusive Economic Zone of maritime nations with those in their soils. Our study focuses on Namibia, where there is a wealth of marine sediment data, and draws comparisons with sediment data from two other countries with different characteristics, which are Pakistan and the United Kingdom. Results Results indicate that marine sediment carbon stocks in maritime nations can be similar in magnitude to those of soils. Therefore, if human activities in these areas are managed, carbon stocks in the oceanic realm—particularly over continental margins—could be considered as part of national GHG inventories. Conclusions This study shows that marine sediment organic carbon stocks can be equal in size or exceed terrestrial carbon stocks of maritime nations. This provides motivation both for improved assessment of sedimentary carbon inventories and for reevaluation of the way that carbon stocks are assessed and valued. The

Stock Control in Automotive Industry with Simulation Utilization

Directory of Open Access Journals (Sweden)

Petra Vegnerová

2008-12-01

Full Text Available At this time in economic environment there is the big trend of coming logistical chain, supply chain and supply chain management (SCM. SCM deals with material and information flows control, inventory management, demand forecast, production plan optimalization, distribution management etc. Nowadays for effective purchase, production and distribution plan and control in companies are utilized the simulation and simulation programmes. This paper deals with the simulation programme Witness and its utilization for finding of results real problems – simulation utilization for stocks solution in automotive industry. The model can be used for the determination of new delivery system of materials and for stocks reduction.

A blue carbon soil database: Tidal wetland stocks for the US National Greenhouse Gas Inventory

Science.gov (United States)

Feagin, R. A.; Eriksson, M.; Hinson, A.; Najjar, R. G.; Kroeger, K. D.; Herrmann, M.; Holmquist, J. R.; Windham-Myers, L.; MacDonald, G. M.; Brown, L. N.; Bianchi, T. S.

2015-12-01

Coastal wetlands contain large reservoirs of carbon, and in 2015 the US National Greenhouse Gas Inventory began the work of placing blue carbon within the national regulatory context. The potential value of a wetland carbon stock, in relation to its location, soon could be influential in determining governmental policy and management activities, or in stimulating market-based CO2 sequestration projects. To meet the national need for high-resolution maps, a blue carbon stock database was developed linking National Wetlands Inventory datasets with the USDA Soil Survey Geographic Database. Users of the database can identify the economic potential for carbon conservation or restoration projects within specific estuarine basins, states, wetland types, physical parameters, and land management activities. The database is geared towards both national-level assessments and local-level inquiries. Spatial analysis of the stocks show high variance within individual estuarine basins, largely dependent on geomorphic position on the landscape, though there are continental scale trends to the carbon distribution as well. Future plans including linking this database with a sedimentary accretion database to predict carbon flux in US tidal wetlands.

Base-Stock Level yang Meminimasi Biaya pada Permasalahan Single Order

Directory of Open Access Journals (Sweden)

Tanti Octavia

2011-01-01

Full Text Available The purpose of this research is to conduct an analysis on demand characteristic and inventory cost which might potentially influence the determination of base-stock level. Appropriate base-stock level will determine the maximum profit and also reduce the stockout cost for fashion products which has high demand uncertainty and single order problem. Case study is applied on a garment company with eight fashion product types that can be classified into short and long lifetime. The effect of coefficient variation, salvage price and stockout cost is analyzed towards profits and base stock level. It can be concluded that demand variability does not affect base stock level, while stockout cost and salvage price does.

Setting safety stocks in multi-stage inventory systems under rolling horizon mathematical programming models

NARCIS (Netherlands)

Boulaksil, Y.; Fransoo, J.C.; van Halm, E.N.G.

2009-01-01

This paper considers the problem of determining safety stocks in multi-item multi-stage inventory systems that face demand uncertainties. Safety stocks are necessary to make the supply chain, which is driven by forecasts of customer orders, responsive to (demand) uncertainties and to achieve

Development of A Web-Based Information System for Material Inventory Control: The Case of An Automotive Company

OpenAIRE

Renjana Setyoandara Wibisono; Tanika D Sofianti; Setijo Awibowo

2016-01-01

Inventory control is controlling the materials movement to fulfill the requirements. The materials can from the direct and indirect materials. the indirect materials are the materials that cannot be calculated according to the bill of materials. Indirect materials need safety stocks, so the requirements can always be fulfilled, means it need the control and monitoring of their levels. To control the movement of the materials, each department have roles to control and information that need to ...

Development of A Web-Based Information System for Material Inventory Control: The Case of An Automotive Company

Directory of Open Access Journals (Sweden)

Renjana Setyoandara Wibisono

2016-10-01

Full Text Available Inventory control is controlling the materials movement to fulfill the requirements. The materials can from the direct and indirect materials. the indirect materials are the materials that cannot be calculated according to the bill of materials. Indirect materials need safety stocks, so the requirements can always be fulfilled, means it need the control and monitoring of their levels. To control the movement of the materials, each department have roles to control and information that need to be shared. PT XYZ is an automotive assembler company, the company need a tool to control the indirect materials inbound and outbound and control its stock. This research is to have the tool that will be a web-based program because to share the information throughout the department of planning, production, and logistics. In developing and implementing the program itself, the RUP methodology is used to guide in doing this research with having four phases and activities that support the research. The result is the program itself have been successful to fulfilled the user requirements. The program shows the real time information for the levels of the materials and also the inbound and outbound of the materials for the user to monitor its levels.

METHODOLOGY AND ORGANIZATION OF ACCOUNTING AND INTERNAL CONTROL OF INVENTORIES OF THE COMPANY IN THE SYSTEM OF ASSET MANAGEMENT

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Koblyanska Olena

2018-03-01

Full Text Available Introduction. The article is devoted to theoretical, methodological and practical issues of accounting and internal control of the company’s stocks in the asset management system. The purpose of the study is to deepen and consolidate the theoretical and practical knowledge of the issues of accounting and internal control of the company’s stocks in the asset management system, identify practical problems with the implementation of the methodology and organization of accounting and internal control of the company’s stocks and develop recommendations for the elimination of deficiencies and improve the accounting and internal control of the company’s stocks. Results. The issue of relevance of proper accounting and internal control of stocks at the enterprise is considered. The research of typical operations with stocks was carried out with the use of the method of their reflection in the account. The classification of stocks, carrying out of their estimation, definition of the initial value, and also the typical correspondence from the account of stocks are resulted. A comparative characteristic of international and national inventory standards was implemented. The article deals with the features of the internal control of inventories at the enterprise, provides normative documents on its organization and methodology, describes the procedure for its implementation at the enterprise and identifies the typical mistakes that occur during its implementation. Conclusions. The questions about theoretical, methodological and practical issues of accounting and internal control of the company’s stocks in the asset management system were considered. A study of typical operations with stocks was carried out with the use of the method of their reflection in the accounts and the features of the internal control of inventories at the enterprise.

Loss-Averse Inventory and Borrowing Decisions with Constraints on Working Capital in Fashion and Textiles Industry

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Lijun Ma

2013-01-01

Full Text Available Traditional inventory models focus on operational decisions and inventory control. Quite few models consider the financial constraint and decision bias such as loss aversion, which are the reality in today's business environment, especially for the fashion and textiles industry. In this paper we study the inventory control problem for a loss-averse retailer with financial constraint for operations in a periodic review setting in a finite horizon. We characterize the optimal inventory control policies with self-financing or with borrowing as capital-dependent base-stock policies. We demonstrate with numerical examples that the optimal base-stock level is nonincreasing in the accumulated wealth and the loss-aversion indicator.

Hanford inventory program user's manual

International Nuclear Information System (INIS)

Hinkelman, K.C.

1994-01-01

Provides users with instructions and information about accessing and operating the Hanford Inventory Program (HIP) system. The Hanford Inventory Program is an integrated control system that provides a single source for the management and control of equipment, parts, and material warehoused by Westinghouse Hanford Company in various site-wide locations. The inventory is comprised of spare parts and equipment, shop stock, special tools, essential materials, and convenience storage items. The HIP replaced the following systems; ACA, ASP, PICS, FSP, WSR, STP, and RBO. In addition, HIP manages the catalog maintenance function for the General Supplies inventory stocked in the 1164 building and managed by WIMS

Validating Virtual Safety Stock Effectiveness through Simulation

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Maria Elena Nenni

2013-08-01

safety stock effectiveness through simulation in an inventory system using a base stock policy with periodic reviews and backorders. This approach can be useful for researchers as well as practitioners who want to model the behaviour of an inventory system under uncertain conditions and verify the opportunity for setting up a virtual safety stock on top of, or instead of, the traditional physical safety stock.

Myopic control of stochastic inventories with intermittent updates: continuous versus periodic replenishment

OpenAIRE

M Shnaiderman

2012-01-01

A manufacturer who is responsible for supplying a retailer with a single product is considered. The retailer sells the product in response to stochastic demand and provides the manufacturer with periodic updates about his inventories. Replenishing the retailer's inventory under two myopic base-stock policies is addressed. These policies, referred to as vendor managed inventory, represent a relatively new approach to allocating responsibility in the replenishment process. Specifically, the man...

Automated Inventory Control System for Nigeria Power Holding ...

African Journals Online (AJOL)

The company may want to release some capital from its inventory investment by reducing stock levels. In addition, manual ways of handling inventory has failed to cope with factors like ... graphical interface ability for decision making.

Optimising a Model of Minimum Stock Level Control and a Model of Standing Order Cycle in Selected Foundry Plant

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Szymszal J.

2013-09-01

Full Text Available It has been found that the area where one can look for significant reserves in the procurement logistics is a rational management of the stock of raw materials. Currently, the main purpose of projects which increase the efficiency of inventory management is to rationalise all the activities in this area, taking into account and minimising at the same time the total inventory costs. The paper presents a method for optimising the inventory level of raw materials under a foundry plant conditions using two different control models. The first model is based on the estimate of an optimal level of the minimum emergency stock of raw materials, giving information about the need for an order to be placed immediately and about the optimal size of consignments ordered after the minimum emergency level has occurred. The second model is based on the estimate of a maximum inventory level of raw materials and an optimal order cycle. Optimisation of the presented models has been based on the previously done selection and use of rational methods for forecasting the time series of the delivery of a chosen auxiliary material (ceramic filters to a casting plant, including forecasting a mean size of the delivered batch of products and its standard deviation.

Inventory control in multi-echelon divergent systems with random lead times

NARCIS (Netherlands)

Heijden, van der M.C.; Diks, E.B.; Kok, de A.G.

1996-01-01

This paper deals with integral inventory control in multi-echelon divergent systems with stochastic lead times. The policy considered is an echelon stock, periodic review, order-up-to (R, S) policy. A computational method is derived to obtain the order-up-to level and the allocation fractions

Inventory control in multi-echelon divergent systems with random lead times

NARCIS (Netherlands)

van der Heijden, Matthijs C.; Diks, Erik; de Kok, Ton

1999-01-01

This paper deals with integral inventory control in multi-echelon divergent systems with stochastic lead times. The policy considered is an echelon stock, periodic review, order-up-to (R, S) policy. A computational method is derived to obtain the order-up-to level and the allocation fractions

A critical spare part inventory control based on hazard function approach: A case study in a garment company

Science.gov (United States)

Melinda, Intan Dewi; Jauhari, Wakhid Ahmad

2018-02-01

Spare part procurement is a complex issue and requires an accurate analysis. Stock outs of spare part can leads a great impact on production. Therefore, it is necessary to design the inventory control of spare parts that guarantee the availability of spare parts needed for supporting the maintenance activity. This paper studies the inventory policy for sewing machine spare part using hazard function to approximate the demand. Hazard function is the indicator of the effect of ageing on the reliability of the system. It quantifies the risk of failure as the age of the system increases. We use a continuous review policy based on Hadley Within Approach to calculate the optimum inventory level for critical spare parts. There are four spare parts categorized as critical spare parts, which are needle plate, feed dog, rotary and binder attachment. The optimal ordering quantity for needle plate, feed, rotary and binder attachment are 5 units, 17 units, 5 units, and 9 units, respectively and the reorder point are 2 units, 1 unit, 2 units and 1 unit, respectively. Finally, the service level achieved by the proposed policy is in a range of 95.91%-97.93%, which indicates that the inventory level of spare parts can be used to support the required parts in the maintenance activity.

Multi-leg Seat Inventory Control Based on EMSU and Virtual Bucket

Directory of Open Access Journals (Sweden)

Wei Fan

2014-01-01

Full Text Available Expected marginal seat revenue (EMSR is a well-known method for airline seat inventory control airlines. However, this method employs a static model to study the dynamic reservation process, and does not take into account the risk tolerance of policy makers. Expected marginal seat utility (EMSU replaces revenue by utility, which addresses the real situation of seat inventory control. However, there is still a lack of multi-leg seat control algorithms based on EMSU. Therefore, using EMSU and bucket algorithms, this paper applies the Markov decision-making process to simulate the flight reservation process and builds a dynamic multi-leg seat inventory control model. Experimental results validate the effectiveness of the proposed method.

Data Driven Tuning of Inventory Controllers

DEFF Research Database (Denmark)

Huusom, Jakob Kjøbsted; Santacoloma, Paloma Andrade; Poulsen, Niels Kjølstad

2007-01-01

A systematic method for criterion based tuning of inventory controllers based on data-driven iterative feedback tuning is presented. This tuning method circumvent problems with modeling bias. The process model used for the design of the inventory control is utilized in the tuning...... as an approximation to reduce time required on experiments. The method is illustrated in an application with a multivariable inventory control implementation on a four tank system....

Enhancements to inventory control procedures used at Koeberg nuclear power station

International Nuclear Information System (INIS)

Barker, M.P.; Adams, A.R.

1991-01-01

In industry today, industrial engineers are forced to seek new and innovative ideas to reduce costs. This can often be accomplished by simplified or modernized operational procedures. With the advancement in computer technology, operational procedures can be enhanced. Despite the fact that Eskom's Koeberg nuclear power station is one of a kind in Africa, it, like most other industries requires a large stock holding capacity. There are currently 25 000 stock items in the Koeberg Stores Information System. Controlling all of these items is no minor task and management is continually trying to optimise the inventory control procedures. One of these procedures is described. 3 refs., 1 fig

Optimal Inventory Control with Advance Supply Information

Directory of Open Access Journals (Sweden)

Marko Jaksic

2016-09-01

Full Text Available It has been shown in numerous situations that sharing information between the companies leads to improved performance of the supply chain. We study a positive lead time periodic-review inventory system of a retailer facing stochastic demand from his customer and stochastic limited supply capacity of the manufacturer supplying the products to him. The consequence of stochastic supply capacity is that the orders might not be delivered in full, and the exact size of the replenishment might not be known to the retailer. The manufacturer is willing to share the so-called advance supply information (ASI about the actual replenishment of the retailer's pipeline order with the retailer. ASI is provided at a certain time after the orders have been placed and the retailer can now use this information to decrease the uncertainty of the supply, and thus improve its inventory policy. For this model, we develop a dynamic programming formulation, and characterize the optimal ordering policy as a state-dependent base-stock policy. In addition, we show some properties of the base-stock level. While the optimal policy is highly complex, we obtain some additional insights by comparing it to the state-dependent myopic inventory policy. We conduct the numerical analysis to estimate the in uence of the system parameters on the value of ASI. While we show that the interaction between the parameters is relatively complex, the general insight is that due to increasing marginal returns, the majority of the benets are gained only in the case of full, or close to full, ASI visibility.

A Dynamic Bayesian Network Model for the Production and Inventory Control

Science.gov (United States)

Shin, Ji-Sun; Takazaki, Noriyuki; Lee, Tae-Hong; Kim, Jin-Il; Lee, Hee-Hyol

In general, the production quantities and delivered goods are changed randomly and then the total stock is also changed randomly. This paper deals with the production and inventory control using the Dynamic Bayesian Network. Bayesian Network is a probabilistic model which represents the qualitative dependence between two or more random variables by the graph structure, and indicates the quantitative relations between individual variables by the conditional probability. The probabilistic distribution of the total stock is calculated through the propagation of the probability on the network. Moreover, an adjusting rule of the production quantities to maintain the probability of a lower limit and a ceiling of the total stock to certain values is shown.

Base stock policies with degraded service to large orders

DEFF Research Database (Denmark)

Du, Bisheng; Larsen, Christian

2011-01-01

and the base stock levels of each rule are such that all customers (of both order types) are indifferent between the two rules. When comparing the difference in the average on-hand inventory levels, we can then make an assessment of the threshold value of the cost of splitting an order (which may otherwise...

30 CFR 220.032 - Inventories.

Science.gov (United States)

2010-07-01

... operations. The accumulation of surplus stocks shall be avoided by proper materiel control, inventory and... physical inventory that has not been credited to NPSL operations under § 220.015(a)(2) shall be credited to... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Inventories. 220.032 Section 220.032 Mineral...

Derivation of confidence intervals of service measures in a base-stock inventory control system with low-frequent demand

DEFF Research Database (Denmark)

Larsen, Christian

We explore a base-stock system with backlogging where the demand process is a compound renewal process and the compound element is a delayed geometric distribution. For this setting it is proven in [4] that the long-run average service measures order fill rate (OFR) and volume fill rate (VFR) are...

Derivation of confidence intervals of service measures in a base-stock inventory control system with low-frequent demand

DEFF Research Database (Denmark)

Larsen, Christian

2011-01-01

We explore a base-stock system with backlogging where the demand process is a compound renewal process and the compound element is a delayed geometric distribution. For this setting it holds that the long-run average service measures order fill rate (OFR) and volume fill rate (VFR) are equal in v...

Exact Fill Rates for (R, s, S) Inventory Control With Gamma Distributed Demand

NARCIS (Netherlands)

Moors, J.J.A.; Strijbosch, L.W.G.

2001-01-01

For the familiar (R; s; S) inventory control system only approximate expressions exist for the fill rate, i.e. the fraction of demand that can be satisfied from stock.Best-known are the approximations derived from renewal theory by Tijms & Groenevelt (1984), holding under specific conditions; in

GENERAL METHOD OF STOCKS AUDIT

Directory of Open Access Journals (Sweden)

Iryna Galushchak

2017-03-01

Full Text Available The article deals with the organization and methodology of accounting and auditing inventory enterprises. Suggestions for improvement of accounting permit to raise processing and presenting economic information to a higher level for making the economic and management decisions. Theory and practice problems of stocks audit were investigated. The basic directions of improvement of  stock audit were defined. The auditor can form an opinion about the state of business transactions of accounting of goods, define shortcomings in its organization and possible directions of elimination of violations and abuses. Program of audit of operations accounting with stocks should include the investigation of the preservation of property, valuation and posting costs, correct evaluation of purchased tangible assets, using of stocks in production. It is worth  to use techniques and methods of verification such as inventory, comparative control,  comparison of documentary evidence, counter check, check arithmetic for  audit of goods. Keywords: audit, stocks, activities of the company.

An Optimization of (Q,r Inventory Policy Based on Health Care Apparel Products with Compound Poisson Demands

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An Pan

2014-01-01

Full Text Available Addressing the problems of a health care center which produces tailor-made clothes for specific people, the paper proposes a single product continuous review model and establishes an optimal policy for the center based on (Q,r control policy to minimize expected average cost on an order cycle. A generic mathematical model to compute cost on real-time inventory level is developed to generate optimal order quantity under stochastic stock variation. The customer demands are described as compound Poisson process. Comparisons on cost between optimization method and experience-based decision on Q are made through numerical studies conducted for the inventory system of the center.

Inventory parameters

CERN Document Server

Sharma, Sanjay

2017-01-01

This book provides a detailed overview of various parameters/factors involved in inventory analysis. It especially focuses on the assessment and modeling of basic inventory parameters, namely demand, procurement cost, cycle time, ordering cost, inventory carrying cost, inventory stock, stock out level, and stock out cost. In the context of economic lot size, it provides equations related to the optimum values. It also discusses why the optimum lot size and optimum total relevant cost are considered to be key decision variables, and uses numerous examples to explain each of these inventory parameters separately. Lastly, it provides detailed information on parameter estimation for different sectors/products. Written in a simple and lucid style, it offers a valuable resource for a broad readership, especially Master of Business Administration (MBA) students.

Optimal Control of a Make-to-Stock System with Outsourced Production and Price-Sensitive Demand

Directory of Open Access Journals (Sweden)

Liuxin Chen

2014-01-01

and a choice of either high or low price, the system decides at any point in time whether to produce or even outsource for additional capacity as well as which price to sell the product at. We show in the paper that the optimal control policy is of dynamic threshold type: all decisions are based on the product inventory position which represents the state of the system; there is a state dependent base stock level to decide on production and a higher level on outsourcing; and there is a state dependent threshold which divides the choice of high and low prices.

LQ optimal and reaching law-based sliding modes for inventory management systems

Science.gov (United States)

Ignaciuk, Przemysław; Bartoszewicz, Andrzej

2012-01-01

In this article, the theory of discrete sliding-mode control is used to design new supply strategies for periodic-review inventory systems. In the considered systems, the stock used to fulfil an unknown, time-varying demand can be replenished from a single supply source or from multiple suppliers procuring orders with different delays. The proposed strategies guarantee that demand is always entirely satisfied from the on-hand stock (yielding the maximum service level), and the warehouse capacity is not exceeded (which eliminates the cost of emergency storage). In contrast to the classical, stochastic approaches, in this article, we focus on optimising the inventory system dynamics. The parameters of the first control strategy are selected by minimising a quadratic cost functional. Next, it is shown how the system dynamical performance can be improved by applying the concept of a reaching law with the appropriately adjusted reaching phase. The stable, nonoscillatory behaviour of the closed-loop system is demonstrated and the properties of the designed controllers are discussed and strictly proved.

Estimating Soil Organic Carbon stocks and uncertainties for the National inventory Report - a study case in Southern Belgium

Science.gov (United States)

Chartin, Caroline; Stevens, Antoine; Kruger, Inken; Esther, Goidts; Carnol, Monique; van Wesemael, Bas

2016-04-01

As many other countries, Belgium complies with Annex I of the United Nations Framework Convention on Climate Change (UNFCCC). Belgium thus reports its annual greenhouse gas emissions in its national inventory report (NIR), with a distinction between emissions/sequestration in cropland and grassland (EU decision 529/2013). The CO2 fluxes are then based on changes in SOC stocks computed for each of these two types of landuse. These stocks are specified for each of the agricultural regions which correspond to areas with similar agricultural practices (rotations and/or livestock) and yield potentials. For Southern Belgium (Wallonia) consisting of ten agricultural regions, the Soil Monitoring Network (SMN) 'CARBOSOL' has been developed this last decade to survey the state of agricultural soils by quantifying SOC stocks and their evolution in a reasonable number of locations complying with the time and funds allocated. Unfortunately, the 592 points of the CARBOSOL network do not allow a representative and a sound estimation of SOC stocks and its uncertainties for the 20 possible combinations of land use/agricultural regions. Moreover, the SMN CARBIOSOL is based on a legacy database following a convenience scheme sampling strategy rather than a statistical scheme defined by design-based or model-based strategies. Here, we aim to both quantify SOC budgets (i.e., How much?) and spatialize SOC stocks (i.e., Where?) at regional scale (Southern Belgium) based on data from the SMN described above. To this end, we developed a computation procedure based on Digital Soil Mapping techniques and stochastic simulations (Monte-Carlo) allowing the estimation of multiple (10,000) independent spatialized datasets. This procedure accounts for the uncertainties associated to estimations of both i) SOC stock at the pixelscale and ii) parameters of the models. Based on these 10,000 individual realizations of the spatial model, mean SOC stocks and confidence intervals can be then computed at

Imputing forest carbon stock estimates from inventory plots to a nationally continuous coverage

Directory of Open Access Journals (Sweden)

Wilson Barry Tyler

2013-01-01

Full Text Available Abstract The U.S. has been providing national-scale estimates of forest carbon (C stocks and stock change to meet United Nations Framework Convention on Climate Change (UNFCCC reporting requirements for years. Although these currently are provided as national estimates by pool and year to meet greenhouse gas monitoring requirements, there is growing need to disaggregate these estimates to finer scales to enable strategic forest management and monitoring activities focused on various ecosystem services such as C storage enhancement. Through application of a nearest-neighbor imputation approach, spatially extant estimates of forest C density were developed for the conterminous U.S. using the U.S.’s annual forest inventory. Results suggest that an existing forest inventory plot imputation approach can be readily modified to provide raster maps of C density across a range of pools (e.g., live tree to soil organic carbon and spatial scales (e.g., sub-county to biome. Comparisons among imputed maps indicate strong regional differences across C pools. The C density of pools closely related to detrital input (e.g., dead wood is often highest in forests suffering from recent mortality events such as those in the northern Rocky Mountains (e.g., beetle infestations. In contrast, live tree carbon density is often highest on the highest quality forest sites such as those found in the Pacific Northwest. Validation results suggest strong agreement between the estimates produced from the forest inventory plots and those from the imputed maps, particularly when the C pool is closely associated with the imputation model (e.g., aboveground live biomass and live tree basal area, with weaker agreement for detrital pools (e.g., standing dead trees. Forest inventory imputed plot maps provide an efficient and flexible approach to monitoring diverse C pools at national (e.g., UNFCCC and regional scales (e.g., Reducing Emissions from Deforestation and Forest

Inventory control in case of unknown demand and control parameters

NARCIS (Netherlands)

Janssen, E.

2010-01-01

This thesis deals with unknown demand and control parameters in inventory control. Inventory control involves decisions on what to order when and in what quantity. These decisions are based on information about the demand. Models are constructed using complete demand information; these models ensure

Control your inventory in a world of lean retailing.

Science.gov (United States)

Abernathy, F H; Dunlop, J T; Hammond, J H; Weil, D

2000-01-01

As retailers adopt lean retailing practices, manufacturers are feeling the pinch. Retailers no longer place large seasonal orders for goods in advance-instead, they require ongoing replenishment of stock, forcing manufacturers to predict demand and then hold substantial inventories indefinitely. Manufacturers now carry the cost of inventory risk--the possibility that demand will dry up and goods will have to be sold below cost. And as product proliferation increases, customer demand becomes harder to predict. Most manufacturers apply one inventory policy for all stock-keeping units in a product line. But the inventory demand for SKUs within the same product line can vary significantly. SKUs with high volume typically have little variation in weekly sales, while slow-selling SKUs can vary enormously in weekly sales. The greater the variation, the larger the inventory the manufacturer must hold relative to an SKU's expected weekly sales. By differentiating inventory policies at the SKU level, manufacturers can reduce inventories for the high-volume SKUs and increase them for the low-volume ones--and thereby improve the profit-ability of the entire line. SKU-level differentiation can also be applied to sourcing strategies. Instead of producing all the SKUs for a product line at a single location, either offshore at low cost or close to market at higher cost, manufacturers can typically do better by going for a mixed allocation. Low-variation goods should be produced mainly offshore, while high-variation goods are best made close to markets.

Inventories and sales uncertainty\\ud

OpenAIRE

Caglayan, M.; Maioli, S.; Mateut, S.

2011-01-01

We investigate the empirical linkages between sales uncertainty and firms´ inventory investment behavior while controlling for firms´ financial strength. Using large panels of manufacturing firms from several European countries we find that higher sales uncertainty leads to larger stocks of inventories. We also identify an indirect effect of sales uncertainty on inventory accumulation through the financial strength of firms. Our results provide evidence that financial strength mitigates the a...

US forest carbon calculation tool: forest-land carbon stocks and net annual stock change

Science.gov (United States)

James E. Smith; Linda S. Heath; Michael C. Nichols

2007-01-01

The Carbon Calculation Tool 4.0, CCTv40.exe, is a computer application that reads publicly available forest inventory data collected by the U.S. Forest Service's Forest Inventory and Analysis Program (FIA) and generates state-level annualized estimates of carbon stocks on forest land based on FORCARB2 estimators. Estimates can be recalculated as...

Inventory management in a metallurgical of the automotive industry

Directory of Open Access Journals (Sweden)

Marcos Antonio Maia de Oliveira

2015-12-01

Full Text Available This article aims to analyze the importance of inventory management in a metallurgical company, located in Santo André city, in Grande São Paulo, since the inventory management is crucial within a company that wants to survive nowadays, by studying the main features and trends in the methods used for inventory control. In this case study the basic concepts for good control were considered, showing tools currently used in the market, providing data for material purchase, sales control, parts in stock, future orders, MRP, storage space, among others once many companies have high and unnecessary cost of stock for not being aware of the real importance of this control. It is felt that the logistics of the company should invest in technology by purchasing the MRP system, visiting fairs and attending seminars. This way, the company will have better inventory control thus consequently decrease the purchase of materials.

Determining supply chain safety stock level and location

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Bahareh Amirjabbari

2014-01-01

Full Text Available Purpose: The lean methodology and its principles have widely been applied in supply chain management in recent decades. Manufacturers are one of the most important contributors in a supply chain and inventory plays a paramount role for them to become lean. Therefore, there should be appropriate management of inventory and all of its drivers in accordance with a lean strategy. Safety stock is one of the main drivers of inventory; it protects against increasing the stretch in the breaking points of the supply chain, which in turn can result in possible reduction of inventory. In this paper an optimization model and a simulation model are developed and applied in a real case to optimize the safety stock level with the objective of logistics cost minimization.Design/methodology/approach: In order to optimize the safety stock level while minimizing logistics costs, a nonlinear cost minimization safety stock model is developed in this paper and then it is applied in a real world manufacturing case company. A safety stock simulation model based on appropriate metrics in the case company’s supply chain performance is also provided.Findings: These models result in not only the optimum levels but also locations of safety stock within the supply chain.Originality/value: In this research, two models of cost minimization and simulation have been developed and also applied in a real case company to result in not only optimized levels but also optimized locations of safety stock across the whole supply chain. In addition, the appropriate supply chain performance measurement metrics have been introduced in this paper and the simulation model is developed based on those.

Sizing inventory of blood products in a blood bank at Brazil based on a model of inventory management and a demand forecast

Directory of Open Access Journals (Sweden)

Julia Lorena Marques Gurgel

2014-02-01

Full Text Available The management of the stocks of products derived from the blood processing collected in blood banks is a problem for health services in Brazil and the world. Quantify the stocks of these products in order to equalize the demand and supply is not a simple task. It's necessary ensure that the product is available when needed and in due time. However, there is no how overestimate these stocks given that the product is perishable and it is not easy the availability of raw material (blood for processing. There are few studies in Brazil, however, that discuss this issue. This study will focus on one Brazilian Hemocentro, which has faced the challenge of measure the demand for haemotherapic's products and establish parameters to control their stocks. Thus, it was sought to adapt a recent study realized out of the country, about sizing of stocks of a inventory for blood banks, combined with a forecast model of demand for blood derivatives subclassified by blood type. This control aims to increase the availability of the transfusion service, as it intends to reduce shortages and wastage of the blood collected.

Information system design of inventory control spare parts maintenance (valuation class 5000) (case study: plant kw)

Science.gov (United States)

Fitriana, Rina; Moengin, Parwadi; Riana, Mega

2016-02-01

Plat KW hadn't using optimal inventory level planning yet and hadn't have an information system that well computerized. The research objective is to be able to design an information system related inventory control of spare parts maintenance. The study focused on five types of spare parts with the highest application rate during February 2013- March 2015 and included in the classification of fast on FSN analysis Grinding stones Cut 4". Cable Tie 15". Welding RB 26-32MM. Ring Plat ½" and Ring Plate 5/8 ". Inventory calculation used Economic Order Quantity (EOQ). Safety Stock (SS) and Reorder Point (ROP) methods. System analysis conducted using the framework PIECES with the proposed inventory control system. the performance of the plant KW relating to the supply of spare parts maintenance needs can be more efficient as well as problems at the company can be answered and can perform inventory cost savings amounting Rp.267.066. A computerized information system of inventory control spare parts maintenance provides a menu that can be accessed by each departments as the user needed.

Proactive inventory policy intervention to mitigate risk within cooperative supply chains

Directory of Open Access Journals (Sweden)

Takako Kurano

2014-04-01

Full Text Available This exploratory paper will investigate the concept of supply chain risk management involving supplier monitoring within a cooperative supply chain. Inventory levels and stockouts are the key metrics. Key to this concept is the assumptions that (1 out-of-control supplier situations are causal triggers for downstream supply chain disruptions, (2 these triggers can potentially be predicted using statistical process monitoring tools, and (3 carrying excess inventory only when needed is preferable as opposed to carrying excess inventory on a continual basis. Simulation experimentation will be used to explore several supplier monitoring strategies based on statistical runs tests, specifically "runs up and down" and/or "runs above and below" tests. The sensitivity of these tests in detecting non-random supplier behavior will be explored and their performance will be investigated relative to stock-outs and inventory levels. Finally, the effects of production capacity and yield rate will be examined. Results indicate out-of-control supplier signals can be detected beforehand and stock-outs can be significantly reduced by dynamically adjusting inventory levels. The largest benefit occurs when both runs tests are used together and when the supplier has sufficient production capacity to respond to downstream demand (i.e., safety stock increases. When supplier capacity is limited, the highest benefit is achieved when yield rates are high and, thus, yield loss does not increase supplier production requirements beyond its available capacity.

COLE: A Web-based Tool for Interfacing with Forest Inventory Data

Science.gov (United States)

Patrick Proctor; Linda S. Heath; Paul C. Van Deusen; Jeffery H. Gove; James E. Smith

2005-01-01

We are developing an online computer program to provide forest carbon related estimates for the conterminous United States (COLE). Version 1.0 of the program features carbon estimates based on data from the USDA Forest Service Eastwide Forest Inventory database. The program allows the user to designate an area of interest, and currently provides area, growing-stock...

Reliability–based economic model predictive control for generalised flow–based networks including actuators’ health–aware capabilities

Directory of Open Access Journals (Sweden)

Grosso Juan M.

2016-09-01

Full Text Available This paper proposes a reliability-based economic model predictive control (MPC strategy for the management of generalised flow-based networks, integrating some ideas on network service reliability, dynamic safety stock planning, and degradation of equipment health. The proposed strategy is based on a single-layer economic optimisation problem with dynamic constraints, which includes two enhancements with respect to existing approaches. The first enhancement considers chance-constraint programming to compute an optimal inventory replenishment policy based on a desired risk acceptability level, leading to dynamical allocation of safety stocks in flow-based networks to satisfy non-stationary flow demands. The second enhancement computes a smart distribution of the control effort and maximises actuators’ availability by estimating their degradation and reliability. The proposed approach is illustrated with an application of water transport networks using the Barcelona network as the case study considered.

Developing Inventory Projection Models Using Empirical Net Forest Growth and Growing-Stock Density Relationships Across U.S. Regions and Species Group

Science.gov (United States)

Prakash Nepal; Peter J. Ince; Kenneth E. Skog; Sun J. Chang

2012-01-01

This paper describes a set of empirical net forest growth models based on forest growing-stock density relationships for three U.S. regions (North, South, and West) and two species groups (softwoods and hardwoods) at the regional aggregate level. The growth models accurately predict historical U.S. timber inventory trends when we incorporate historical timber harvests...

A production inventory model with deteriorating items and shortages

Directory of Open Access Journals (Sweden)

Samanta G.P.

2004-01-01

Full Text Available A continuous production control inventory model for deteriorating items with shortages is developed. A number of structural properties of the inventory system are studied analytically. The formulae for the optimal average system cost, stock level, backlog level and production cycle time are derived when the deterioration rate is very small. Numerical examples are taken to illustrate the procedure of finding the optimal total inventory cost, stock level, backlog level and production cycle time. Sensitivity analysis is carried out to demonstrate the effects of changing parameter values on the optimal solution of the system.

A comparison between the order and the volume fill rates for a base-stock inventory control system under a compound renewal demand process

DEFF Research Database (Denmark)

Larsen, Christian; Thorstenson, Anders

The order fill rate is less commonly used than the volume fill rate (most often just denoted fill rate) as a performance measure for inventory control systems. However, in settings where the focus is on filling customer orders rather than total quantities, the order fill rate should be the prefer......The order fill rate is less commonly used than the volume fill rate (most often just denoted fill rate) as a performance measure for inventory control systems. However, in settings where the focus is on filling customer orders rather than total quantities, the order fill rate should...

Real-time plutonium accountability and inventory control system

International Nuclear Information System (INIS)

Sarich, J.P.

An on-line inventory system for a large storage and processing facility is planned. A terminal system will provide for interactive updating and information retrieval. The data base will contain information on inventory items and transactions, as well as process monitoring information and laboratory bookkeeping data. Access to the terminals, as well as the storage vaults, will be controlled by fingerprint comparison with a personnel identification data base. Bar code labels attached to each inventory item will be read by a light pen during physical inventories and when materials are transferred. The use of devices to continuously monitor and control storage locations within the vaults is planned. (U.S.)

Real-time plutonium accountability and inventory control system

International Nuclear Information System (INIS)

Sarich, J.P.

1975-01-01

An on-line inventory system for a large storage and processing facility is planned. A terminal system will provide for interactive updating and information retrieval. The data base will contain information on inventory items and transactions, as well as process monitoring information and laboratory bookkeeping data. Access to the terminals, as well as the storage vaults, will be controlled by fingerprint comparison with a personnel identification data base. Bar code labels attached to each inventory item will be read by a light pen during physical inventories and when material is transferred. The use of devices to continuously monitor and control s locations within the vaults is planned

Vendor Managed Inventory:Retail Industry Perspective of Malaysia

OpenAIRE

Madjlesi Taklimi, Zahra

2011-01-01

The concept of Vendor Managed Inventory (VMI) radically changes a traditional inventory management. Under the typical business model, the buyer or retailer is in total control of the timing and volume of the order, in order placing and managing the inventory plan. Whereas VMI is a supply chain initiative where the supplier is responsible for all decisions regarding inventories at the retailers, i.e. under VMI program the supplier is authorized to manage inventories of agreed-upon stock-keepin...

Rule Based System for Medicine Inventory Control Using Radio Frequency Identification (RFID

Directory of Open Access Journals (Sweden)

Ardhyanti Mita Nugraha Joanna

2018-01-01

Full Text Available Rule based system is very efficient to ensure stock of drug to remain available by utilizing Radio Frequency Identification (RFID as input means automatically. This method can ensure the stock of drugs to remain available by analyzing the needs of drug users. The research data was the amount of drug usage in hospital for 1 year. The data was processed by using ABC classification to determine the drug with fast, medium and slow movement. In each classification result, rule based algorithm was given for determination of safety stock and Reorder Point (ROP. This research yielded safety stock and ROP values that vary depending on the class of each drug. Validation is done by comparing the calculation of safety stock and reorder point both manually and by system, then, it was found that the mean deviation value at safety stock was 0,03 and and ROP was 0,08.

Rule Based System for Medicine Inventory Control Using Radio Frequency Identification (RFID)

Science.gov (United States)

Nugraha, Joanna Ardhyanti Mita; Suryono; Suseno, dan Jatmiko Endro

2018-02-01

Rule based system is very efficient to ensure stock of drug to remain available by utilizing Radio Frequency Identification (RFID) as input means automatically. This method can ensure the stock of drugs to remain available by analyzing the needs of drug users. The research data was the amount of drug usage in hospital for 1 year. The data was processed by using ABC classification to determine the drug with fast, medium and slow movement. In each classification result, rule based algorithm was given for determination of safety stock and Reorder Point (ROP). This research yielded safety stock and ROP values that vary depending on the class of each drug. Validation is done by comparing the calculation of safety stock and reorder point both manually and by system, then, it was found that the mean deviation value at safety stock was 0,03 and and ROP was 0,08.

A CASE-BASED ROADMAP FOR LATERAL TRANSSHIPMENT IN SUPPLY CHAIN INVENTORY MANAGEMENT

Directory of Open Access Journals (Sweden)

Henry Lau

2016-04-01

Full Text Available Manufacturers and wholesalers are increasingly cost conscious in response to today’s hyper-competitive environment. Lateral transshipment (LT has been proposed as a viable solution to drive total inventory costs down whilst increasing customer service level. Our study proposes five LT decision rules with a case-based roadmap to guide professional inventory management. Results of this large fast moving consumer goods case study company demonstrate superior inventory management performance with implementing a combined reactive and proactive LT strategy to determine whether to transship emergency stock from other warehouse or to backorder from suppliers, size of transshipment, favorite wholesaler, preferred supplier, and extra quantity for preventive LT, which are the key LT decision points among the professional supply chain management practitioners.

Dynamic Evolution Analysis of Stock Price Fluctuation and Its Control

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Yuhua Xu

2018-01-01

Full Text Available This paper studies a simple dynamical system of stock price fluctuation time series based on the rule of stock market. When the stock price fluctuation system is disturbed by external excitations, the system exhibits obviously chaotic phenomena, and its basic dynamic properties are analyzed. At the same time, a new fixed-time convergence theorem is proposed for achieving fixed-time control of stock price fluctuation system. Finally, the effectiveness of the method is verified by numerical simulation.

27 CFR 46.195 - Floor stocks requirements.

Science.gov (United States)

2010-04-01

... Tubes Held for Sale on April 1, 2009 General § 46.195 Floor stocks requirements. (a) Take inventory. The dealer must establish the quantity of articles subject to the floor stocks tax held for sale on April 1, 2009. The dealer may take a physical inventory or may use a record (book) inventory, as specified in...

LQ Optimal Sliding Mode Control of Periodic Review Perishable Inventories with Transportation Losses

OpenAIRE

Leśniewski, Piotr; Bartoszewicz, Andrzej

2013-01-01

In this work we apply the control-theoretic approach to design a new replenishment strategy for inventory systems with perishable stock. Such systems are supposed to effectively satisfy an unknown and permanently time-varying consumers’ demand. The main obstacle of achieving this goal is the need of obtaining supplies from a distant source. During the supply process goods are inevitably lost due to various causes. Furthermore, those goods which successfully arrive at the distribution center s...

Research on Multi-leg Inventory Control Based on Passenger Choice

OpenAIRE

Fan, Wei; Su, Qiubo; Ip, Wai Hung

2014-01-01

To remedy the lack of mathematical programming and the Expected Marginal Seat Revenue (EMSR) model for multi-leg seat inventory control, this paper proposes a method based on passenger choice. Except for data about which seats passengers decide to opt for, there is no need to obtain distributions of passengers’ demands or other “a priori” information. The proposed method can discover the real factors that affect passengers’ choices, and then estimate the probabilities of seat choices and the ...

Spatially explicit analysis of field inventories for national forest carbon monitoring

Directory of Open Access Journals (Sweden)

David C. Marvin

2016-06-01

Full Text Available Abstract Background Tropical forests provide a crucial carbon sink for a sizable portion of annual global CO2 emissions. Policies that incentivize tropical forest conservation by monetizing forest carbon ultimately depend on accurate estimates of national carbon stocks, which are often based on field inventory sampling. As an exercise to understand the limitations of field inventory sampling, we tested whether two common field-plot sampling approaches could accurately estimate carbon stocks across approximately 76 million ha of Perúvian forests. A 1-ha resolution LiDAR-based map of carbon stocks was used as a model of the country’s carbon geography. Results Both field inventory sampling approaches worked well in estimating total national carbon stocks, almost always falling within 10 % of the model national total. However, the sampling approaches were unable to produce accurate spatially-explicit estimates of the carbon geography of Perú, with estimates falling within 10 % of the model carbon geography across no more than 44 % of the country. We did not find any associations between carbon stock errors from the field plot estimates and six different environmental variables. Conclusions Field inventory plot sampling does not provide accurate carbon geography for a tropical country with wide ranging environmental gradients such as Perú. The lack of association between estimated carbon errors and environmental variables suggests field inventory sampling results from other nations would not differ from those reported here. Tropical forest nations should understand the risks associated with primarily field-based sampling approaches, and consider alternatives leading to more effective forest conservation and climate change mitigation.

A credit policy approach in a two-warehouse inventory model for deteriorating items with price- and stock-dependent demand under partial backlogging

Science.gov (United States)

Panda, Gobinda Chandra; Khan, Md. Al-Amin; Shaikh, Ali Akbar

2018-04-01

Advertisement of the product is an important factor in inventory analysis. Also, price and stock have an important role to attract more customers in the competitive business situations. Trade credit policy is another important role in inventory analysis. We have combined these three factors together in a two-warehouse inventory model and represented it mathematically. In addition, we have added deteriorating factor of our proposed problem with price- and stock-dependent demand under partial backlogged shortage and solved. The frequency of advertisement is considered constant for a year in this paper. The proposed model is highly nonlinear in nature. Due to highly nonlinearity, we could not find the closed form solution. In this paper, trade credit facility is taken in the perspective of retailer, and all the possible cases and subcases of the model are discussed and solved using lingo 10.0 software. The results of sensitivity analysis prove the effectiveness of the proposed model.

Interfacing internet of things technologies of RFID, XMPP and Twitter to reduce inaccuracies in inventory management

CSIR Research Space (South Africa)

Mathaba, S

2012-05-01

Full Text Available processes. These processes include forecasting, stock replenishment, ordering, and effective utilization of stock information. Inventory accuracy is a key problem if overlooked. Inventory systems need to have accurate inventory records of stock on hand... of book inventory in parallel with the stock on hand within specified time intervals. Stock on hand and book inventory is compared to check the inventory to be ordered and inventory on hand. Inventory management systems are able to calculate PI...

Periodic inventory system in cafeteria using linear programming

Science.gov (United States)

Usop, Mohd Fais; Ishak, Ruzana; Hamdan, Ahmad Ridhuan

2017-11-01

Inventory management is an important factor in running a business. It plays a big role of managing the stock in cafeteria. If the inventories are failed to be managed wisely, it will affect the profit of the cafeteria. Therefore, the purpose of this study is to find the solution of the inventory management in cafeteria. Most of the cafeteria in Malaysia did not manage their stock well. Therefore, this study is to propose a database system of inventory management and to develop the inventory model in cafeteria management. In this study, new database system to improve the management of the stock in a weekly basis will be provided using Linear Programming Model to get the optimal range of the inventory needed for selected categories. Data that were collected by using the Periodic Inventory System at the end of the week within three months period being analyzed by using the Food Stock-take Database. The inventory model was developed from the collected data according to the category of the inventory in the cafeteria. Results showed the effectiveness of using the Periodic Inventory System and will be very helpful to the cafeteria management in organizing the inventory. Moreover, the findings in this study can reduce the cost of operation and increased the profit.

An Inventory Controlled Supply Chain Model Based on Improved BP Neural Network

Directory of Open Access Journals (Sweden)

Wei He

2013-01-01

Full Text Available Inventory control is a key factor for reducing supply chain cost and increasing customer satisfaction. However, prediction of inventory level is a challenging task for managers. As one of the widely used techniques for inventory control, standard BP neural network has such problems as low convergence rate and poor prediction accuracy. Aiming at these problems, a new fast convergent BP neural network model for predicting inventory level is developed in this paper. By adding an error offset, this paper deduces the new chain propagation rule and the new weight formula. This paper also applies the improved BP neural network model to predict the inventory level of an automotive parts company. The results show that the improved algorithm not only significantly exceeds the standard algorithm but also outperforms some other improved BP algorithms both on convergence rate and prediction accuracy.

Global stocks of selected mineral-based commodities

Science.gov (United States)

Wilburn, David R.; Bleiwas, Donald I.; Karl, Nick A.

2016-12-05

IntroductionThe U.S. Geological Survey, National Minerals Information Center, analyzes mineral and metal supply chains by identifying and describing major components of mineral and material flows from ore extraction, through intermediate forms, to a final product. This report focuses on an important component of the world’s supply chain: the amounts and global distribution of major consumer, producer, and exchange stocks of selected mineral commodities. In this report, the term “stock” is used instead of “inventory” and refers to accumulations of mined ore, intermediate products, and refined mineral-based commodities that are in a form that meets the agreed-upon specifications of a buyer or processor of intermediate products. These may include certain ores such as bauxite, concentrates, smelter products, and refined metals. Materials sometimes referred to as inventory for accounting purposes, such as ore contained in a deposit or in a leach pile, or materials that need to be further processed before they can be shipped to a consumer, are not considered. Stocks may be held (owned) by consumers, governments, investors, producers, and traders. They may serve as (1) a means to achieve economic, social, and strategic goals through government policies; (2) a secure source of supply to meet demand and to mitigate potential shortages in the supply chain; (3) a hedge to mitigate price volatility; and (4) vehicles for speculative investment.The paucity and uneven reliability of data for stocks of ores and concentrates and for material held by producers, consumers, and merchants hinder the accurate estimating of the size and distribution of this portion of the supply chain for certain commodities. This paper reviews the more visible stocks held in commodity exchange warehouses distributed throughout the world.

Activity based costing model for inventory valuation

Directory of Open Access Journals (Sweden)

Vineet Chouhan

2017-03-01

Full Text Available Activity-Based-Model (ABC is used for the purpose of significant improvement for overhead accounting systems by providing the best information required for managerial decision. This pa-per discusses implacability of ABC technique on inventory valuation as a management account-ing innovation. In order to prove the applicability of ABC for inventory control a material driven medium-sized and privately owned company from engineering (iron and steel industry is select-ed and by analysis of its production process and its material dependency and use of indirect in-ventory, an ABC model is explored for better inventory control. The case revealed that the ne-cessity of ABC in the area of inventory control is significant. The company is not only able to increase its quality of decision but also it can significantly analyze its cost of direct material cost, valuation of direct material and use its implications for better decision making.

Stock-based Compensation Plans and Employee Incentives

OpenAIRE

Jan Zabojnik

2014-01-01

Standard principal-agent theory predicts that large firms should not use employee stock options and other stock-based compensation to provide incentives to non-executive employees. Yet, business practitioners appear to believe that stock-based compensation improves incentives, and mounting empirical evidence points to the same conclusion. This paper provides an explanation for why stock-based incentives can be effective. In the model of this paper, employee stock options complement individual...

Steam Generator control in Nuclear Power Plants by water mass inventory

Energy Technology Data Exchange (ETDEWEB)

Dong Wei [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States); Doster, J. Michael [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)], E-mail: doster@eos.ncsu.edu; Mayo, Charles W. [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)

2008-04-15

Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators.

Steam Generator control in Nuclear Power Plants by water mass inventory

International Nuclear Information System (INIS)

Dong Wei; Doster, J. Michael; Mayo, Charles W.

2008-01-01

Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators

Solving a Novel Inventory Location Model with Stochastic Constraints and (R,s,S Inventory Control Policy

Directory of Open Access Journals (Sweden)

Guillermo Cabrera

2013-01-01

Full Text Available We solve a novel inventory-location model with a stochastic capacity constraint based on a periodic inventory control (ILM-PR policy. The ILM-PR policy implies several changes with regard to other previous models proposed in the literature, which consider continuous review as their inventory policy. One of these changes is the inclusion of the undershoot concept, which has not been considered in previous ILM models in the literature. Based on our model, we are able to design a distribution network for a two-level supply chain, addressing both warehouse location and customer assignment decisions, whilst taking into consideration several aspects of inventory planning, in particular, evaluating the impact of the inventory control review period on the network configuration and system costs. Because the model is a very hard-to solve combinatorial nonlinear optimisation problem, we implemented two heuristics to solve it, namely, Tabu Search and Particle Swarm Optimisation. These approaches were tested over small instances in which they were able to find the optimal solution in just a few seconds. Because the model is a new one, a set of medium-size instances is provided that can be useful as a benchmark in future research. The heuristics showed a good convergence rate when applied to those instances. The results confirm that decision making over the inventory control policy has effects on the distribution network design.

System-oriented inventory models for spare parts

NARCIS (Netherlands)

Basten, R.J.I.; Houtum, van G.J.J.A.N.

2014-01-01

Stocks of spare parts, located at appropriate locations, can prevent long downtimes of technical systems that are used in the primary processes of their users. Since such downtimes are typically very expensive, generally system-oriented service measures are used in spare parts inventory control.

Optimal strategy analysis based on robust predictive control for inventory system with random demand

Science.gov (United States)

Saputra, Aditya; Widowati, Sutrisno

2017-12-01

In this paper, the optimal strategy for a single product single supplier inventory system with random demand is analyzed by using robust predictive control with additive random parameter. We formulate the dynamical system of this system as a linear state space with additive random parameter. To determine and analyze the optimal strategy for the given inventory system, we use robust predictive control approach which gives the optimal strategy i.e. the optimal product volume that should be purchased from the supplier for each time period so that the expected cost is minimal. A numerical simulation is performed with some generated random inventory data. We simulate in MATLAB software where the inventory level must be controlled as close as possible to a set point decided by us. From the results, robust predictive control model provides the optimal strategy i.e. the optimal product volume that should be purchased and the inventory level was followed the given set point.

Inventory control based on advanced probability theory, an application

CERN Document Server

Krever, Maarten; Schorr, Bernd; Wunderink, S

2005-01-01

Whenever stock is placed as a buffer between consumption and supply the decision when to replenish the stock is based on uncertain values of future demand and supply variables. Uncertainty exists about the replenishment lead time, about the number of demands and the quantities demanded during this period. We develop a new analytical expression for the reorder point, which is based on the desired service level and three distributions: the distribution of the quantity of single demands during lead time, the distribution of the lengths of time intervals between successive demands, and the distribution of the lead time itself. The distribution of lead time demand is derived from the distributions of individual demand quantities and not from the demand per period. It is not surprising that the resulting formulae for the mean and variance are different from those currently used. The theory developed is also applicable to periodic review systems. The system has been implemented at CERN and enables a significant enha...

Elevation-based upscaling of organic carbon stocks in High-Arctic permafrost terrain

DEFF Research Database (Denmark)

Weiss, Niels; Faucherre, Samuel; Lampiris, Nikos

2017-01-01

Accurate quantity and distribution estimates of permafrost soil organic carbon (SOC) stocks are needed to project potential feedbacks to climate, following warming. Still, upscaling from local field observations to regional estimates to circumarctic assessments remains a challenge. Here we explore...... elevation-based upscaling techniques for High-Arctic permafrost SOC stocks. We combine two detailed, high-resolution SOC inventories on Spitsbergen (Svalbard) with regional validation data. We find a clear relationship between elevation and SOC content, and use this observed exponential correlation, as well...... as discrete elevation classes, as upscaling models for Spitsbergen. We estimate the total amount of permafrost SOC currently present in soils on Spitsbergen to be 105.36 Tg (0.11 Pg), with a mean SOC content of 2.84 ± 0.74 kg C m−2 (mean ± 95% confidence interval). Excluding glaciers and permanent snowfields...

Effects of rapid urban sprawl on urban forest carbon stocks: integrating remotely sensed, GIS and forest inventory data.

Science.gov (United States)

Ren, Yin; Yan, Jing; Wei, Xiaohua; Wang, Yajun; Yang, Yusheng; Hua, Lizhong; Xiong, Yongzhu; Niu, Xiang; Song, Xiaodong

2012-12-30

Research on the effects of urban sprawl on carbon stocks within urban forests can help support policy for sustainable urban design. This is particularly important given climate change and environmental deterioration as a result of rapid urbanization. The purpose of this study was to quantify the effects of urban sprawl on dynamics of forest carbon stock and density in Xiamen, a typical city experiencing rapid urbanization in China. Forest resource inventory data collected from 32,898 patches in 4 years (1972, 1988, 1996 and 2006), together with remotely sensed data (from 1988, 1996 and 2006), were used to investigate vegetation carbon densities and stocks in Xiamen, China. We classified the forests into four groups: (1) forest patches connected to construction land; (2) forest patches connected to farmland; (3) forest patches connected to both construction land and farmland and (4) close forest patches. Carbon stocks and densities of four different types of forest patches during different urbanization periods in three zones (urban core, suburb and exurb) were compared to assess the impact of human disturbance on forest carbon. In the urban core, the carbon stock and carbon density in all four forest patch types declined over the study period. In the suburbs, different urbanization processes influenced forest carbon density and carbon stock in all four forest patch types. Urban sprawl negatively affected the surrounding forests. In the exurbs, the carbon stock and carbon density in all four forest patch types tended to increase over the study period. The results revealed that human disturbance played the dominant role in influencing the carbon stock and density of forest patches close to the locations of human activities. In forest patches far away from the locations of human activities, natural forest regrowth was the dominant factor affecting carbon stock and density. Copyright © 2012 Elsevier Ltd. All rights reserved.

Uncertainty of forest carbon stock changes. Implications to the total uncertainty of GHG inventory of Finland

International Nuclear Information System (INIS)

Monni, S.; Savolainen, I.; Peltoniemi, M.; Lehtonen, A.; Makipaa, R.; Palosuo, T.

2007-01-01

Uncertainty analysis facilitates identification of the most important categories affecting greenhouse gas (GHG) inventory uncertainty and helps in prioritisation of the efforts needed for development of the inventory. This paper presents an uncertainty analysis of GHG emissions of all Kyoto sectors and gases for Finland consolidated with estimates of emissions/removals from LULUCF categories. In Finland, net GHG emissions in 2003 were around 69 Tg (±15 Tg) CO2 equivalents. The uncertainties in forest carbon sink estimates in 2003 were larger than in most other emission categories, but of the same order of magnitude as in carbon stock change estimates in other land use, land-use change and forestry (LULUCF) categories, and in N2O emissions from agricultural soils. Uncertainties in sink estimates of 1990 were lower, due to better availability of data. Results of this study indicate that inclusion of the forest carbon sink to GHG inventories reported to the UNFCCC increases uncertainties in net emissions notably. However, the decrease in precision is accompanied by an increase in the accuracy of the overall net GHG emissions due to improved completeness of the inventory. The results of this study can be utilised when planning future GHG mitigation protocols and emission trading schemes and when analysing environmental benefits of climate conventions

Development and validation of a stock addiction inventory (SAI).

Science.gov (United States)

Youn, HyunChul; Choi, Jung-Seok; Kim, Dai-Jin; Choi, Sam-Wook

2016-01-01

Investing in financial markets is promoted and protected by the government as an essential economic activity, but can turn into a gambling addiction problem. Until now, few scales have widely been used to identify gambling addicts in financial markets. This study aimed to develop a self-rating scale to distinguish them. In addition, the reliability and validity of the stock addiction inventory (SAI) were demonstrated. A set of questionnaires, including the SAI, south oaks gambling screen (SOGS), and DSM-5 diagnostic criteria, for gambling disorder was completed by 1005 participants. Factor analysis, internal consistency testing, t tests, analysis of variance, and partial correlation analysis were conducted to verify the reliability and validity of SAI. The factor analysis results showed the final SAI consisting of two factors and nine items. The internal consistency and concurrent validity of SAI were verified. The Cronbach's α for the total scale was 0.892, and the SAI and its factors were significantly correlated with SOGS. This study developed a specific scale for financial market investments or trading; this scale proved to be reliable and valid. Our scale expands the understanding of gambling addiction in financial markets and provides a diagnostic reference.

Comparison of calculation methods for estimating annual carbon stock change in German forests under forest management in the German greenhouse gas inventory.

Science.gov (United States)

Röhling, Steffi; Dunger, Karsten; Kändler, Gerald; Klatt, Susann; Riedel, Thomas; Stümer, Wolfgang; Brötz, Johannes

2016-12-01

The German greenhouse gas inventory in the land use change sector strongly depends on national forest inventory data. As these data were collected periodically 1987, 2002, 2008 and 2012, the time series on emissions show several "jumps" due to biomass stock change, especially between 2001 and 2002 and between 2007 and 2008 while within the periods the emissions seem to be constant due to the application of periodical average emission factors. This does not reflect inter-annual variability in the time series, which would be assumed as the drivers for the carbon stock changes fluctuate between the years. Therefore additional data, which is available on annual basis, should be introduced into the calculations of the emissions inventories in order to get more plausible time series. This article explores the possibility of introducing an annual rather than periodical approach to calculating emission factors with the given data and thus smoothing the trajectory of time series for emissions from forest biomass. Two approaches are introduced to estimate annual changes derived from periodic data: the so-called logging factor method and the growth factor method. The logging factor method incorporates annual logging data to project annual values from periodic values. This is less complex to implement than the growth factor method, which additionally adds growth data into the calculations. Calculation of the input variables is based on sound statistical methodologies and periodically collected data that cannot be altered. Thus a discontinuous trajectory of the emissions over time remains, even after the adjustments. It is intended to adopt this approach in the German greenhouse gas reporting in order to meet the request for annually adjusted values.

Stock-based vs. fleet-based evaluation of the multi-annual management plan for the cod stocks in the Baltic Sea

DEFF Research Database (Denmark)

Bastardie, Francois; Vinther, Morten; Nielsen, J. Rasmus

2010-01-01

parameters are assumed constant. For the Eastern Baltic stock, additional sources of uncertainties from fishery adaptation to the plan are tested using a fleet-based and spatially explicit version of the model which leads to higher reductions in F and no significant change in management robustness......This study evaluated the EU 2008 multi-annual plan for Baltic cod stock recovery. The plan combines harvest control rules that set TACs with reductions in direct effort (E) and fishing mortality (F). Performance and robustness of the plan are tested with a management strategy evaluation model (MSE...

Formation of initial cost of stocks of own production

Directory of Open Access Journals (Sweden)

Elena Krukovskiy

2016-06-01

Full Text Available The concept and component stocks according to national accounting standards are revealed. The procedure for forming the initial value of the stock, depending on the way they arrive at the company according to the guidelines as well as methods for evaluating stocks of own production is grounded. The methodological principles of formation of information on stocks and the disclosure of its financial statements are considered. In the article investigated the procedure of forming the original value of stocks depending on how they flow to the enterprise. Number of methods of assessment of inventory, which can be used to reflect their value in the accounting and financial reporting, and methods of evaluation of own production is characterized. Identified costs are included in the initial cost of inventories, including inventories of own production. The estimation of the definition of agricultural produce at fair value and features of its application in the enterprise is proposed by authors.

Forest inventory-based estimation of carbon stocks and flux in California forests in 1990.

Science.gov (United States)

Jeremy S. Fried; Xiaoping. Zhou

2008-01-01

Estimates of forest carbon stores and flux for California circa 1990 were modeled from forest inventory data in support of California’s legislatively mandated greenhouse gas inventory. Reliable estimates of live-tree carbon stores and flux on timberlands outside of national forest could be calculated from periodic inventory data collected in the 1980s and 1990s;...

Volatility of sales, expectation errors, and inventory investment : Firm level evidence

NARCIS (Netherlands)

Bo, H

2001-01-01

This paper tests whether demand uncertainty, which is measured by the volatility of sales, affects inventory investment based on the accelerator buffer stock inventory model. Using a panel of Dutch listed firms in the period 1984-1996, we find that the estimated coefficient of the speed parameter of

Statistical Control Charts: Performances of Short Term Stock Trading in Croatia

Directory of Open Access Journals (Sweden)

Dumičić Ksenija

2015-03-01

Full Text Available Background: The stock exchange, as a regulated financial market, in modern economies reflects their economic development level. The stock market indicates the mood of investors in the development of a country and is an important ingredient for growth. Objectives: This paper aims to introduce an additional statistical tool used to support the decision-making process in stock trading, and it investigate the usage of statistical process control (SPC methods into the stock trading process. Methods/Approach: The individual (I, exponentially weighted moving average (EWMA and cumulative sum (CUSUM control charts were used for gaining trade signals. The open and the average prices of CROBEX10 index stocks on the Zagreb Stock Exchange were used in the analysis. The statistical control charts capabilities for stock trading in the short-run were analysed. Results: The statistical control chart analysis pointed out too many signals to buy or sell stocks. Most of them are considered as false alarms. So, the statistical control charts showed to be not so much useful in stock trading or in a portfolio analysis. Conclusions: The presence of non-normality and autocorellation has great impact on statistical control charts performances. It is assumed that if these two problems are solved, the use of statistical control charts in a portfolio analysis could be greatly improved.

Pooled inventory management: a unique cost-sharing program

International Nuclear Information System (INIS)

Bromenschenkel, K.E.

1984-01-01

A totally fresh approach to stocking an inventory of costly, long-lead-time nuclear plant equipment became a reality in January, 1981, after three years of effort to form the program. The program, known as Pooled Inventory Management (PIM), is now procuring the first equipment to be stocked in its inventory. This report describes the formation of PIM, how the program works, PIM accomplishments, equipment included in PIM stockpiles, and economics, implementation, and future plans of the program

Comparison of regression coefficient and GIS-based methodologies for regional estimates of forest soil carbon stocks

International Nuclear Information System (INIS)

Elliott Campbell, J.; Moen, Jeremie C.; Ney, Richard A.; Schnoor, Jerald L.

2008-01-01

Estimates of forest soil organic carbon (SOC) have applications in carbon science, soil quality studies, carbon sequestration technologies, and carbon trading. Forest SOC has been modeled using a regression coefficient methodology that applies mean SOC densities (mass/area) to broad forest regions. A higher resolution model is based on an approach that employs a geographic information system (GIS) with soil databases and satellite-derived landcover images. Despite this advancement, the regression approach remains the basis of current state and federal level greenhouse gas inventories. Both approaches are analyzed in detail for Wisconsin forest soils from 1983 to 2001, applying rigorous error-fixing algorithms to soil databases. Resulting SOC stock estimates are 20% larger when determined using the GIS method rather than the regression approach. Average annual rates of increase in SOC stocks are 3.6 and 1.0 million metric tons of carbon per year for the GIS and regression approaches respectively. - Large differences in estimates of soil organic carbon stocks and annual changes in stocks for Wisconsin forestlands indicate a need for validation from forthcoming forest surveys

Considering inventory distributions in a stochastic periodic inventory routing system

Science.gov (United States)

Yadollahi, Ehsan; Aghezzaf, El-Houssaine

2017-07-01

Dealing with the stochasticity of parameters is one of the critical issues in business and industry nowadays. Supply chain planners have difficulties in forecasting stochastic parameters of a distribution system. Demand rates of customers during their lead time are one of these parameters. In addition, holding a huge level of inventory at the retailers is costly and inefficient. To cover the uncertainty of forecasting demand rates, researchers have proposed the usage of safety stock to avoid stock-out. However, finding the precise level of safety stock depends on forecasting the statistical distribution of demand rates and their variations in different settings among the planning horizon. In this paper the demand rate distributions and its parameters are taken into account for each time period in a stochastic periodic IRP. An analysis of the achieved statistical distribution of the inventory and safety stock level is provided to measure the effects of input parameters on the output indicators. Different values for coefficient of variation are applied to the customers' demand rate in the optimization model. The outcome of the deterministic equivalent model of SPIRP is simulated in form of an illustrative case.

PENGENDALIAN PERSEDIAAN MENGGUNAKAN PENDEKATAN DYNAMIC INVENTORY DENGAN MEMPERTIMBANGKAN KETIDAKPASTIAN PERMINTAAN, YIELD, DAN LEADTIME

Directory of Open Access Journals (Sweden)

Sri Hartini

2012-01-01

Inventory, Dynamic Inventory     Abstract    Inventory management is one of serious problem faced by companies. PT Garuda Putra – Putri Jaya (PT GPPJ Pati is company which produce snack, like coated peanuts, soybean snack, and pillus. With a purpose to support production’s fluency which is afected in consumer demand fulfillment’ fluency, then PT GPPJ Pati management try to assure the availability of roll pack material. But, the failure in inventory management causing overstock in inventory of roll pack material which showed in high value of Days of Inventory (DOI. Based from preliminary research for knowing factors that affected to higher value of DOI, was concluded that the higher value of DOI caused by determination of order quantity that only consider farecast of roll pack material’s need, quantity of safety stock, and outstanding inventory in warehouse without calcuation process and still using intuition and experience of worker. Based form preliminary research, this research try to compared inventory control policy used by company (current policy, and  ( inventory model based form forecasting with uncertainty demand, yield, and lead time which developed by Mohammed Zied Babai [Baba06]. Study of policy comparison was done with implementation of spreadsheet simulation with two policy scenario. From this simulation and policy analysis, was concluded that scenario 2 is best inventory control policy because deliver smallest DOI value, i.e. 36.02 days, and lowest inventory cost, i.e. Rp 5,775,116.41. Key words : Uncertainty Lead Time, Uncertainty Demand, Uncertainty Yield, Days of Inventory, Dynamic Inventory

The Aspects Of Inventory Controlling Instruments Implementation In The System Of Retail Chains Finance Management

OpenAIRE

Nataliya Buratchuk

2014-01-01

The article deals with issues of implementation of inventory controlling instruments in the system of retail chains finance management. The author suggests expanded classification of methods and instruments of inventory controlling distinguishing 3 groups of specific instruments: logistic controlling instruments, expenditures and supply chains controlling instruments and inventory special controlling mechanisms. Based on investigation of controlling methods and instruments, the approximate li...

Inventory Control of Spare Parts for Operating Nuclear Power plants

Energy Technology Data Exchange (ETDEWEB)

Park, Jong-Hyuck; Jang, Se-Jin; Hwang, Eui-Youp; Yoo, Sung-Soo; Yoo, Keun-Bae; Lee, Sang-Guk; Hong, Sung-Yull [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

2006-07-01

Inventory control of spare parts plays an increasingly important role in operation management. The trade-off is clear: on one hand a large number of spare parts ties up a large amount of capital, while on the other hand too little inventory may result in extremely costly emergency actions. This is why during the last few decades inventory of spare parts control has been the topics of many publications. Recently management systems such as manufacturing resources planning (MRP) and enterprise resource planning (ERP) have been added. However, most of these contributions have similar theoretical background. This means the concepts and techniques are mainly based on mathematical assumptions and modeling inventory of spare parts situations Nuclear utilities in Korea have several problems to manage the optimum level of spare parts though they used MRP System. Because most of items have long lead time and they are imported from United States, Canada, France and so on. In this paper, we will examine the available inventory optimization models which are applicable to nuclear power plant and then select optimum model and assumptions to make inventory of spare parts strategies. Then we develop the computer program to select and determine optimum level of spare parts which should be automatically controlled by KHNP ERP system. The main contribution of this paper is an inventory of spare parts control model development, which can be applied to nuclear power plants in Korea.

Inventory Control of Spare Parts for Operating Nuclear Power plants

International Nuclear Information System (INIS)

Park, Jong-Hyuck; Jang, Se-Jin; Hwang, Eui-Youp; Yoo, Sung-Soo; Yoo, Keun-Bae; Lee, Sang-Guk; Hong, Sung-Yull

2006-01-01

Inventory control of spare parts plays an increasingly important role in operation management. The trade-off is clear: on one hand a large number of spare parts ties up a large amount of capital, while on the other hand too little inventory may result in extremely costly emergency actions. This is why during the last few decades inventory of spare parts control has been the topics of many publications. Recently management systems such as manufacturing resources planning (MRP) and enterprise resource planning (ERP) have been added. However, most of these contributions have similar theoretical background. This means the concepts and techniques are mainly based on mathematical assumptions and modeling inventory of spare parts situations Nuclear utilities in Korea have several problems to manage the optimum level of spare parts though they used MRP System. Because most of items have long lead time and they are imported from United States, Canada, France and so on. In this paper, we will examine the available inventory optimization models which are applicable to nuclear power plant and then select optimum model and assumptions to make inventory of spare parts strategies. Then we develop the computer program to select and determine optimum level of spare parts which should be automatically controlled by KHNP ERP system. The main contribution of this paper is an inventory of spare parts control model development, which can be applied to nuclear power plants in Korea

A statistical power analysis of woody carbon flux from forest inventory data

Science.gov (United States)

James A. Westfall; Christopher W. Woodall; Mark A. Hatfield

2013-01-01

At a national scale, the carbon (C) balance of numerous forest ecosystem C pools can be monitored using a stock change approach based on national forest inventory data. Given the potential influence of disturbance events and/or climate change processes, the statistical detection of changes in forest C stocks is paramount to maintaining the net sequestration status of...

Accounting for biomass carbon stock change due to wildfire in temperate forest landscapes in Australia.

Science.gov (United States)

Keith, Heather; Lindenmayer, David B; Mackey, Brendan G; Blair, David; Carter, Lauren; McBurney, Lachlan; Okada, Sachiko; Konishi-Nagano, Tomoko

2014-01-01

Carbon stock change due to forest management and disturbance must be accounted for in UNFCCC national inventory reports and for signatories to the Kyoto Protocol. Impacts of disturbance on greenhouse gas (GHG) inventories are important for many countries with large forest estates prone to wildfires. Our objective was to measure changes in carbon stocks due to short-term combustion and to simulate longer-term carbon stock dynamics resulting from redistribution among biomass components following wildfire. We studied the impacts of a wildfire in 2009 that burnt temperate forest of tall, wet eucalypts in south-eastern Australia. Biomass combusted ranged from 40 to 58 tC ha(-1), which represented 6-7% and 9-14% in low- and high-severity fire, respectively, of the pre-fire total biomass carbon stock. Pre-fire total stock ranged from 400 to 1040 tC ha(-1) depending on forest age and disturbance history. An estimated 3.9 TgC was emitted from the 2009 fire within the forest region, representing 8.5% of total biomass carbon stock across the landscape. Carbon losses from combustion were large over hours to days during the wildfire, but from an ecosystem dynamics perspective, the proportion of total carbon stock combusted was relatively small. Furthermore, more than half the stock losses from combustion were derived from biomass components with short lifetimes. Most biomass remained on-site, although redistributed from living to dead components. Decomposition of these components and new regeneration constituted the greatest changes in carbon stocks over ensuing decades. A critical issue for carbon accounting policy arises because the timeframes of ecological processes of carbon stock change are longer than the periods for reporting GHG inventories for national emissions reductions targets. Carbon accounts should be comprehensive of all stock changes, but reporting against targets should be based on human-induced changes in carbon stocks to incentivise mitigation activities.

Base-age invariance and inventory projections

Science.gov (United States)

C. J. Cieszewski; R. L. Bailey; B. E. Borders; G. H. Brister; B. D. Shiver

2000-01-01

One of the most important functions of forest inventory is to facilitate management decisions towards forest sustainability based on inventory projections into the future. Therefore, most forest inventories are used for predicting future states of the forests, in modern forestry the most common methods used in inventory projections are based on implicit functions...

Optimal Control Inventory Stochastic With Production Deteriorating

Science.gov (United States)

Affandi, Pardi

2018-01-01

In this paper, we are using optimal control approach to determine the optimal rate in production. Most of the inventory production models deal with a single item. First build the mathematical models inventory stochastic, in this model we also assume that the items are in the same store. The mathematical model of the problem inventory can be deterministic and stochastic models. In this research will be discussed how to model the stochastic as well as how to solve the inventory model using optimal control techniques. The main tool in the study problems for the necessary optimality conditions in the form of the Pontryagin maximum principle involves the Hamilton function. So we can have the optimal production rate in a production inventory system where items are subject deterioration.

Expected value based fuzzy programming approach to solve integrated supplier selection and inventory control problem with fuzzy demand

Science.gov (United States)

Sutrisno; Widowati; Sunarsih; Kartono

2018-01-01

In this paper, a mathematical model in quadratic programming with fuzzy parameter is proposed to determine the optimal strategy for integrated inventory control and supplier selection problem with fuzzy demand. To solve the corresponding optimization problem, we use the expected value based fuzzy programming. Numerical examples are performed to evaluate the model. From the results, the optimal amount of each product that have to be purchased from each supplier for each time period and the optimal amount of each product that have to be stored in the inventory for each time period were determined with minimum total cost and the inventory level was sufficiently closed to the reference level.

Joint Optimization of Distribution Network Design and Two-Echelon Inventory Control with Stochastic Demand and CO2 Emission Tax Charges.

Science.gov (United States)

Li, Shuangyan; Li, Xialian; Zhang, Dezhi; Zhou, Lingyun

2017-01-01

This study develops an optimization model to integrate facility location and inventory control for a three-level distribution network consisting of a supplier, multiple distribution centers (DCs), and multiple retailers. The integrated model addressed in this study simultaneously determines three types of decisions: (1) facility location (optimal number, location, and size of DCs); (2) allocation (assignment of suppliers to located DCs and retailers to located DCs, and corresponding optimal transport mode choices); and (3) inventory control decisions on order quantities, reorder points, and amount of safety stock at each retailer and opened DC. A mixed-integer programming model is presented, which considers the carbon emission taxes, multiple transport modes, stochastic demand, and replenishment lead time. The goal is to minimize the total cost, which covers the fixed costs of logistics facilities, inventory, transportation, and CO2 emission tax charges. The aforementioned optimal model was solved using commercial software LINGO 11. A numerical example is provided to illustrate the applications of the proposed model. The findings show that carbon emission taxes can significantly affect the supply chain structure, inventory level, and carbon emission reduction levels. The delay rate directly affects the replenishment decision of a retailer.

Joint Optimization of Distribution Network Design and Two-Echelon Inventory Control with Stochastic Demand and CO2 Emission Tax Charges.

Directory of Open Access Journals (Sweden)

Shuangyan Li

Full Text Available This study develops an optimization model to integrate facility location and inventory control for a three-level distribution network consisting of a supplier, multiple distribution centers (DCs, and multiple retailers. The integrated model addressed in this study simultaneously determines three types of decisions: (1 facility location (optimal number, location, and size of DCs; (2 allocation (assignment of suppliers to located DCs and retailers to located DCs, and corresponding optimal transport mode choices; and (3 inventory control decisions on order quantities, reorder points, and amount of safety stock at each retailer and opened DC. A mixed-integer programming model is presented, which considers the carbon emission taxes, multiple transport modes, stochastic demand, and replenishment lead time. The goal is to minimize the total cost, which covers the fixed costs of logistics facilities, inventory, transportation, and CO2 emission tax charges. The aforementioned optimal model was solved using commercial software LINGO 11. A numerical example is provided to illustrate the applications of the proposed model. The findings show that carbon emission taxes can significantly affect the supply chain structure, inventory level, and carbon emission reduction levels. The delay rate directly affects the replenishment decision of a retailer.

An Agent-Based Computational Model for China’s Stock Market and Stock Index Futures Market

Directory of Open Access Journals (Sweden)

Hai-Chuan Xu

2014-01-01

Full Text Available This study presents an agent-based computational cross market model for Chinese equity market structure, which includes both stocks and CSI 300 index futures. In this model, we design several stocks and one index future to simulate this structure. This model allows heterogeneous investors to make investment decisions with restrictions including wealth, market trading mechanism, and risk management. Investors’ demands and order submissions are endogenously determined. Our model successfully reproduces several key features of the Chinese financial markets including spot-futures basis distribution, bid-ask spread distribution, volatility clustering, and long memory in absolute returns. Our model can be applied in cross market risk control, market mechanism design, and arbitrage strategies analysis.

Inference for lidar-assisted estimation of forest growing stock volume

Science.gov (United States)

Ronald E. McRoberts; Erik Næsset; Terje. Gobakken

2013-01-01

Estimates of growing stock volume are reported by the national forest inventories (NFI) of most countries and may serve as the basis for aboveground biomass and carbon estimates as required by an increasing number of international agreements. The probability-based (design-based) statistical estimators traditionally used by NFIs to calculate estimates are generally...

Accounting concept of inventories in postindustrial economy

Directory of Open Access Journals (Sweden)

Pravdyuk N.L.

2017-06-01

Full Text Available The accounting of inventories has undergone significant changes over a relatively short period of time. It has changed the scientific picture of their definition and classification, measurement and write-offs reflected in the financial statements. However, these changes happen without proper interpretation and system analysis. And, at least in general terms the inventories are conducted in Ukraine according to IFRS; this causes some obstacles to the objective reflection of working capital of enterprises, and the transparency of disclosure and is not conducive to the formation of a proper investment climate. It is established that the information provision inventory control must meet the requirements of the postindustrial economy by the complicating and deepening the complexity of accounting, the introduction of new forms and their synthesis with the current one, a gradual reorganization to ensure the needs of consumers and enterprise evaluation. The results of the study have substantiated the fundamentals of accounting concepts in the postindustrial economy in the part of the circulating capital, which forms inventories. The information support of inventory management should be implemented in a hierarchical way, when it first and foremost analyzes the working capital, and further deals with inventories and stocks as its subordinate components. The author considers the material goods to be a broader concept than reserves, because they have a dual nature both estimated as the share of negotiable assets, and as the physical component of material costs. The paper gives the definition of this category of symbiosis, which is based on P(CBU 9. The general structure of the current inventories are of significant importance, which has differences in industries, the dominant of which is agriculture, industry, construction, trade, material production. The postindustrial economy caused the questions of differentiation of concepts "production" and "material

Reactivity-based industrial volatile organic compounds emission inventory and its implications for ozone control strategies in China

Science.gov (United States)

Liang, Xiaoming; Chen, Xiaofang; Zhang, Jiani; Shi, Tianli; Sun, Xibo; Fan, Liya; Wang, Liming; Ye, Daiqi

2017-08-01

Increasingly serious ozone (O3) pollution, along with decreasing NOx emission, is creating a big challenge in the control of volatile organic compounds (VOCs) in China. More efficient and effective measures are assuredly needed for controlling VOCs. In this study, a reactivity-based industrial VOCs emission inventory was established in China based on the concept of ozone formation potential (OFP). Key VOCs species, major VOCs sources, and dominant regions with high reactivity were identified. Our results show that the top 15 OFP-based species, including m/p-xylene, toluene, propene, o-xylene, and ethyl benzene, contribute 69% of the total OFP but only 30% of the total emission. The architectural decoration industry, oil refinery industry, storage and transport, and seven other sources constituted the top 10 OFP subsectors, together contributing a total of 85%. The provincial and spatial characteristics of OFP are generally consistent with those of mass-based inventory. The implications for O3 control strategies in China are discussed. We propose a reactivity-based national definition of VOCs and low-reactive substitution strategies, combined with evaluations of health risks. Priority should be given to the top 15 or more species with high reactivity through their major emission sources. Reactivity-based policies should be flexibly applied for O3 mitigation based on the sensitivity of O3 formation conditions.

Automated refueling inventory control system at FFTF

International Nuclear Information System (INIS)

Ordonez, C.R.

1983-10-01

The Refueling Inventory Control System (RICS) at the Fast Flux Test Facility (FFTF) keeps track of all assemblies that reside in the various refueling facilities. The automated RICS allows the user to obtain information regarding any assembly under its control by displaying the data on a screen. It also provides a simulation mode which allows assembly moves on a duplicated data base. This simulation is used to verify the refueling documentation before it is issued

Optimization of Inventories for Multiple Companies by Fuzzy Control Method

OpenAIRE

Kawase, Koichi; Konishi, Masami; Imai, Jun

2008-01-01

In this research, Fuzzy control theory is applied to the inventory control of the supply chain between multiple companies. The proposed control method deals with the amountof inventories expressing supply chain between multiple companies. Referring past demand and tardiness, inventory amounts of raw materials are determined by Fuzzy inference. The method that an appropriate inventory control becomes possible optimizing fuzzy control gain by using SA method for Fuzzy control. The variation of ...

Inventory Control System for a Healthcare Apparel Service Centre with Stockout Risk: A Case Analysis.

Science.gov (United States)

Pan, An; Hui, Chi-Leung

2017-01-01

Based on the real-world inventory control problem of a capacitated healthcare apparel service centre in Hong Kong which provides tailor-made apparel-making services for the elderly and disabled people, this paper studies a partial backordered continuous review inventory control problem in which the product demand follows a Poisson process with a constant lead time. The system is controlled by an ( Q , r ) inventory policy which incorporate the stockout risk, storage capacity, and partial backlog. The healthcare apparel service centre, under the capacity constraint, aims to minimize the inventory cost and achieving a low stockout risk. To address this challenge, an optimization problem is constructed. A real case-based data analysis is conducted, and the result shows that the expected total cost on an order cycle is reduced substantially at around 20% with our proposed optimal inventory control policy. An extensive sensitivity analysis is conducted to generate additional insights.

Financial liberalization and stock market cross-correlation: MF-DCCA analysis based on Shanghai-Hong Kong Stock Connect

Science.gov (United States)

Ruan, Qingsong; Zhang, Shuhua; Lv, Dayong; Lu, Xinsheng

2018-02-01

Based on the implementation of Shanghai-Hong Kong Stock Connect in China, this paper examines the effects of financial liberalization on stock market comovement using both multifractal detrended fluctuation analysis (MF-DFA) and multifractal detrended cross-correlation analysis (MF-DCCA) methods. Results based on MF-DFA confirm the multifractality of Shanghai and Hong Kong stock markets, and the market efficiency of Shanghai stock market increased after the implementation of this connect program. Besides, analysis based on MF-DCCA has verified the existence of persistent cross-correlation between Shanghai and Hong Kong stock markets, and the cross-correlation gets stronger after the launch of this liberalization program. Finally, we find that fat-tail distribution is the main source of multifractality in the cross-correlations before the stock connect program, while long-range correlation contributes to the multifractality after this program.

An expert system for spare parts inventory control

International Nuclear Information System (INIS)

Kim, K.Y.; Chen, P.Y.C.; Okrent, D.

1987-01-01

This paper describes an expert system which can handle spare part requirements not only in corrective maintenance (CM) or preventive maintenance (PM), but also when failure rates of components or parts are updated by new data or by predictive maintenance (PDM), and which can also decide optimum stocking level of each spare part. This expert system provides a maintenance (or inventory) manager with an improved basis for decision making in the maintenance related to spare parts. The definitions of PM and PDM from NUREG-1212 (USNRC 1986) are used herein. This expert system used Intellignece/Compiler (Intelligence Ware, 1986) as a language/tool in the IBM-PC

Inventory Control System for a Healthcare Apparel Service Centre with Stockout Risk: A Case Analysis

Directory of Open Access Journals (Sweden)

An Pan

2017-01-01

Full Text Available Based on the real-world inventory control problem of a capacitated healthcare apparel service centre in Hong Kong which provides tailor-made apparel-making services for the elderly and disabled people, this paper studies a partial backordered continuous review inventory control problem in which the product demand follows a Poisson process with a constant lead time. The system is controlled by an (Q,r inventory policy which incorporate the stockout risk, storage capacity, and partial backlog. The healthcare apparel service centre, under the capacity constraint, aims to minimize the inventory cost and achieving a low stockout risk. To address this challenge, an optimization problem is constructed. A real case-based data analysis is conducted, and the result shows that the expected total cost on an order cycle is reduced substantially at around 20% with our proposed optimal inventory control policy. An extensive sensitivity analysis is conducted to generate additional insights.

Accounting for Biomass Carbon Stock Change Due to Wildfire in Temperate Forest Landscapes in Australia

Science.gov (United States)

Keith, Heather; Lindenmayer, David B.; Mackey, Brendan G.; Blair, David; Carter, Lauren; McBurney, Lachlan; Okada, Sachiko; Konishi-Nagano, Tomoko

2014-01-01

Carbon stock change due to forest management and disturbance must be accounted for in UNFCCC national inventory reports and for signatories to the Kyoto Protocol. Impacts of disturbance on greenhouse gas (GHG) inventories are important for many countries with large forest estates prone to wildfires. Our objective was to measure changes in carbon stocks due to short-term combustion and to simulate longer-term carbon stock dynamics resulting from redistribution among biomass components following wildfire. We studied the impacts of a wildfire in 2009 that burnt temperate forest of tall, wet eucalypts in south-eastern Australia. Biomass combusted ranged from 40 to 58 tC ha−1, which represented 6–7% and 9–14% in low- and high-severity fire, respectively, of the pre-fire total biomass carbon stock. Pre-fire total stock ranged from 400 to 1040 tC ha−1 depending on forest age and disturbance history. An estimated 3.9 TgC was emitted from the 2009 fire within the forest region, representing 8.5% of total biomass carbon stock across the landscape. Carbon losses from combustion were large over hours to days during the wildfire, but from an ecosystem dynamics perspective, the proportion of total carbon stock combusted was relatively small. Furthermore, more than half the stock losses from combustion were derived from biomass components with short lifetimes. Most biomass remained on-site, although redistributed from living to dead components. Decomposition of these components and new regeneration constituted the greatest changes in carbon stocks over ensuing decades. A critical issue for carbon accounting policy arises because the timeframes of ecological processes of carbon stock change are longer than the periods for reporting GHG inventories for national emissions reductions targets. Carbon accounts should be comprehensive of all stock changes, but reporting against targets should be based on human-induced changes in carbon stocks to incentivise mitigation activities

Endogenous Business Cycle Dynamics within Metzlers Inventory Model: Adding an Inventory Floor.

Science.gov (United States)

Sushko, Irina; Wegener, Michael; Westerhoff, Frank; Zaklan, Georg

2009-04-01

Metzlers inventory model may produce dampened fluctuations in economic activity, thus contributing to our understanding of business cycle dynamics. For some parameter combinations, however, the model generates oscillations with increasing amplitude, implying that the inventory stock of firms eventually turns negative. Taking this observation into account, we reformulate Metzlers model by simply putting a floor to the inventory level. Within the new piecewise linear model, endogenous business cycle dynamics may now be triggered via a center bifurcation, i.e. for certain parameter combinations production changes are (quasi-)periodic.

A Global Chance-Constraint for Stochastic Inventory Systems under Service Level Constraints

NARCIS (Netherlands)

Rossi, R.; Tarim, S.A.; Hnich, B.; Prestwich, S.

2008-01-01

We consider a class of production/inventory control problems that has a single product and a single stocking location, for which a stochastic demand with a known non-stationary probability distribution is given. Under the widely-known replenishment cycle policy the problem of computing policy

Analysis of an economic order quantity and reorder point inventory ...

African Journals Online (AJOL)

SIBA group has been faced with an ineffective forecasting method that has led to multiple product stock outs. The issue faced has caused sales loss as well as profit loss,. This research goes through the process of analyzing the company's current forecasting model and recommending an inventory control model to help her ...

Combined make-to-order and make-to-stock in a food production system

NARCIS (Netherlands)

Soman, Chetan Anil; Donk, Dirk Pieter van; Gaalman, Gerard

2002-01-01

The research into multi-product production/inventory control systems has mainly assumed one of the two strategies: Make-to-Order (MTO) or Make-to-Stock (MTS). In practice, however, many companies cater to an increasing variety of products with varying logistical demands (e.g. short due dates,

Combined make-to-order and make-to-stock in a food production system

NARCIS (Netherlands)

Soman, C.A.; van Donk, D.P.; Gaalman, G.J.C.

2004-01-01

The research into multi-product production/inventory control systems has mainly assumed one of the two strategies: make-to-order (MTO) or make-to-stock (MTS). In practice, however, many companies cater to an increasing variety of products with varying logistical demands (e.g. short due dates,

Diagnostic and proposal for use of safety inventory into finished products for a plastics company

Directory of Open Access Journals (Sweden)

Elpidio Oscar Benitez Nara

2013-02-01

Full Text Available The stock is essential for companies. Thinking about it, it is increasingly necessary to develop techniques that seek to reduce inventory levels making them suitable to the company structure and satisfactorily meet the needs of increasingly demanding customers while maintaining the service level. The safety stock is derived from various uncertainties such as shortage of raw materials and difficulties in producing variations in sales projections thus scaling of this safety stock is a most difficult task to perform. In this sense, the present study aims to demonstrate the Inventory Management structure acceptable to a company that seeks to reduce capital invested in stocks as well as a for continuous review reorder point. The research was developed through an analysis of the current policy Inventories of the company, where we sought the most representative products of the product line. For these products it was necessary future sales forecasts for the annual period where it was possible to scale according to company politic Inventories of the average stocks of these products in order to compare with the stocks of securities calculated using specific equations. Then, using the equations it was also defined the point of application of all the studied products was defined, as a model for continuous revision product line studied. Finally the proposed method for use of safety stock techniques showed good results as a reduction of approximately 43% of capital invested in safety stock if compared to current Inventories policy of the company.

Effects of stocking density of freshwater prawn Macrobrachium rosenbergii and addition of different levels of tilapia Oreochromis niloticus on production in C/N controlled periphyton based system

NARCIS (Netherlands)

Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Mondal, M.N.; Azim, M.E.

2009-01-01

An on-station trial was conducted to evaluate the effect of stocking density of freshwater prawn and addition of different levels of tilapia on production in carbon/nitrogen (C/N) controlled periphyton based system. The experiment had a 2 × 3 factorial design, in which two levels of prawn stocking

STOCK MANAGEMENT IN A MANUFACTURING AND TRADING COMPANY

OpenAIRE

Ewa Kempa

2009-01-01

The article shows stock management in the logistic context on the example of a manufacturing and trading company. Stock is one of the most important, and, at the same time, the most difficult issues related to company management as it requires efficient handling of transport and inventory. Also, the amount of stock should possibly be optimal so it does not account for too high operating costs of a company.

The zero inflation of standing dead tree carbon stocks

Science.gov (United States)

Christopher W. Woodall; David W. MacFarlane

2012-01-01

Given the importance of standing dead trees in numerous forest ecosystem attributes/processes such as carbon (C) stocks, the USDA Forest Service’s Forest Inventory and Analysis (FIA) program began consistent nationwide sampling of standing dead trees in 1999. Modeled estimates of standing dead tree C stocks are currently used as the official C stock estimates for the...

19 CFR 146.93 - Inventory control and recordkeeping system.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Inventory control and recordkeeping system. 146.93... § 146.93 Inventory control and recordkeeping system. (a) Attribution. All final products removed from or... provided for under § 146.95(b) of this subpart. (3) Other inventory method. An operator may use the FIFO...

Savannah River Plant's Accountability Inventory Management System (AIMS) (Nuclear materials inventory control)

International Nuclear Information System (INIS)

Croom, R.G.

1976-06-01

The Accountability Inventory Management System (AIMS) is a new computer inventory control system for nuclear materials at the Savannah River Plant, Aiken, South Carolina. The system has two major components, inventory files and system parameter files. AIMS, part of the overall safeguards program, maintains an up-to-date record of nuclear material by location, produces reports required by ERDA in addition to onplant reports, and is capable of a wide range of response to changing input/output requirements through use of user-prepared parameter cards, as opposed to basic system reprogramming

Dead wood inventory and assessment in South Korea

Science.gov (United States)

Jong-Su Yim; Rae Hyun Kim; Sun-Jeong Lee; Yeongmo. Son

2015-01-01

Dead wood (DW) plays a critical role not only in maintaining biodiversity but also in stocking carbon under UNFCCC. From the 5th national forest inventory (NFI5; 2006-2010) in South Korea, field data relevant to the DW including standing and downed dead trees by four decay class, etc. were collected. Based on the NFI5 data,...

A soft computing-based approach to optimise queuing-inventory control problem

Science.gov (United States)

Alaghebandha, Mohammad; Hajipour, Vahid

2015-04-01

In this paper, a multi-product continuous review inventory control problem within batch arrival queuing approach (MQr/M/1) is developed to find the optimal quantities of maximum inventory. The objective function is to minimise summation of ordering, holding and shortage costs under warehouse space, service level and expected lost-sales shortage cost constraints from retailer and warehouse viewpoints. Since the proposed model is Non-deterministic Polynomial-time hard, an efficient imperialist competitive algorithm (ICA) is proposed to solve the model. To justify proposed ICA, both ganetic algorithm and simulated annealing algorithm are utilised. In order to determine the best value of algorithm parameters that result in a better solution, a fine-tuning procedure is executed. Finally, the performance of the proposed ICA is analysed using some numerical illustrations.

Implementing Lean Six Sigma to achieve inventory control in supply chain management

Science.gov (United States)

Hong, Chen

2017-11-01

The inventory cost has important impact on the production cost. In order to get the maximum circulation of funds of enterprise with minimum inventory cost, the inventory control with Lean Six Sigma is presented in supply chain management. The inventory includes both the raw material and the semi-finished parts in manufacturing process. Though the inventory is often studied, the inventory control in manufacturing process is seldom mentioned. This paper reports the inventory control from the perspective of manufacturing process by using statistical techniques including DMAIC, Control Chart, and Statistical Process Control. The process stability is evaluated and the process capability is verified with Lean Six Sigma philosophy. The demonstration in power meter production shows the inventory is decreased from 25% to 0.4%, which indicates the inventory control can be achieved with Lean Six Sigma philosophy and the inventory cost in production can be saved for future sustainable development in supply chain management.

Measuring and modeling carbon stock change estimates for US forests and uncertainties from apparent inter-annual variability

Science.gov (United States)

James E. Smith; Linda S. Heath

2015-01-01

Our approach is based on a collection of models that convert or augment the USDA Forest Inventory and Analysis program survey data to estimate all forest carbon component stocks, including live and standing dead tree aboveground and belowground biomass, forest floor (litter), down deadwood, and soil organic carbon, for each inventory plot. The data, which include...

Inventory management systems : Control and information issues

NARCIS (Netherlands)

Janssen, F.B.S.L.P.

1998-01-01

This dissertation addresses the management of inventory systems. The thesis starts with an exposition on mathematical models that can be used in inventory theory. Then we deal with some information issues related to the demand process. Namely, how to control products that have intermittent demand.

Control Predictivo Aplicado a la Gestión de Stocks en Farmacia Hospitalaria: un Enfoque Orientado a la Minimización del Riesgo

Directory of Open Access Journals (Sweden)

J.M. Maestre

2013-04-01

Full Text Available Resumen: La gestión de stock es una de las principales tareas que lleva a cabo el Servicio de Farmacia de un hospital. Se trata de un problema complejo que requiere establecer un equilibrio entre criterios de optimización diferentes y, a veces, contrapuestos. La complejidad del problema se ve incrementada debido a la incorporación de restricciones tales como retrasos en las entregas de los medicamentos o variabilidad en la demanda. En este trabajo proponemos aplicar el control predictivo basado en modelo (MPC al problema de gestión de stock de un Servicio de Farmacia desde una perspectiva de minimización del riesgo. Las acciones de mitigación se llevan a cabo con el objetivo de reducir el impacto de los posibles riesgos que pueden ocurrir. Por lo tanto, se añaden al problema inicial nuevas variables de decisión. Dado que estas variables pueden ser booleanas, el problema se formula como un problema de programación cuadrática mixto-entero. Finalmente, la metodología propuesta es utilizada en simulación utilizando datos procedentes de un hospital real. Abstract: Inventory management is one of the main tasks that the pharmacy department has to carry out in a hospital. It is a complex problem that requires to establish a tradeoff between different and contradictory optimization criteria. The complexity of the problem is increased by the constrains that naturally arise in stock management problems such as variable delays or stochastic demands. In this work we propose to apply model predictive control (CPBM to the pharmacy department inventory management problem from a risk mitigation perspective. Mitigation actions are executed to reduce the impact of the possible risks that may occur. Hence, new decision variables are added to the initial problem. Given that these variables may be boolean, the problem is formulated as a mixed integer quadratic programming. The proposed methodology is put to test in simulations based on data proceeding

Optimal Acquisition and Inventory Control for a Remanufacturing System

Directory of Open Access Journals (Sweden)

Zhigang Jiang

2013-01-01

Full Text Available Optimal acquisition and inventory control can often make the difference between successful and unsuccessful remanufacturing. However, there is a greater degree of uncertainty and complexity in a remanufacturing system, which leads to a critical need for planning and control models designed to deal with this added uncertainty and complexity. In this paper, a method for optimal acquisition and inventory control of a remanufacturing system is presented. The method considers three inventories, one for returned item and the other for serviceable and recoverable items. Taking the holding cost for returns, recoverable and remanufactured products, remanufacturing cost, disposal cost, and the loss caused by backlog into account, the optimal inventory control model is established to minimize the total costs. Finally, a numerical example is provided to illustrate the proposed methods.

LQ Optimal Sliding Mode Control of Periodic Review Perishable Inventories with Transportation Losses

Directory of Open Access Journals (Sweden)

Piotr Leśniewski

2013-01-01

Full Text Available In this work we apply the control-theoretic approach to design a new replenishment strategy for inventory systems with perishable stock. Such systems are supposed to effectively satisfy an unknown and permanently time-varying consumers’ demand. The main obstacle of achieving this goal is the need of obtaining supplies from a distant source. During the supply process goods are inevitably lost due to various causes. Furthermore, those goods which successfully arrive at the distribution center still deteriorate while stored in its warehouse. We explicitly take into account both of these factors in designing our control strategy. We propose a sliding mode strategy and choose its parameters to minimize a quadratic quality criterion. This approach allows us to ameliorate the bullwhip effect (the amplification of the demand variations when going up in the supply chain. The control strategy proposed in this work ensures bounded orders, guarantees full consumers’ demand satisfaction, and eliminates the risk of exceeding the warehouse capacity. These properties are stated in three theorems and proved in the paper.

Using a remote sensing-based, percent tree cover map to enhance forest inventory estimation

Science.gov (United States)

Ronald E. McRoberts; Greg C. Liknes; Grant M. Domke

2014-01-01

For most national forest inventories, the variables of primary interest to users are forest area and growing stock volume. The precision of estimates of parameters related to these variables can be increased using remotely sensed auxiliary variables, often in combination with stratified estimators. However, acquisition and processing of large amounts of remotely sensed...

Evaluating the Potential of Commercial Forest Inventory Data to Report on Forest Carbon Stock and Forest Carbon Stock Changes for REDD+ under the UNFCCC

Directory of Open Access Journals (Sweden)

Danae Maniatis

2011-01-01

Full Text Available In the context of the adoption at the 16th Conference of the Parties in 2010 on the REDD+ mitigation mechanism, it is important to obtain reliable data on the spatiotemporal variation of forest carbon stocks and changes (called Emission Factor, EF. A re-occurring debate in estimating EF for REDD+ is the use of existing field measurement data. We provide an assessment of the use of commercial logging inventory data and ecological data to estimate a conservative EF (REDD+ phase 2 or to report on EF following IPCC Guidance and Guidelines (REDD+ phase 3. The data presented originate from five logging companies dispersed over Gabon, totalling 2,240 plots of 0.3 hectares.We distinguish three Forest Types (FTs in the dataset based on floristic conditions. Estimated mean aboveground biomass (AGB in the FTs ranges from 312 to 333 Mg ha−1. A 5% accuracy is reached with the number of plots put in place for the FTs and a low sampling uncertainty obtained (± 10 to 13 Mg ha−1. The data could be used to estimate a conservative EF in REDD+ phase 2 and only partially to report on EF following tier 2 requirements for a phase 3.

A stochastic inventory policy with limited transportation capacity

NARCIS (Netherlands)

Dabia, S.; Kiesmüller, G.P.; Dellaert, N.P.

2007-01-01

In this paper we consider a stochastic single-item inventory problem. A retailer keeps a single product on stock to satisfy customers stochastic demand. The retailer is replenished periodically from a supplier with ample stock. For the delivery of the product, trucks with finite capacity are

A new approximate evaluation method for two-echelon inventory systems with emergency shipments

NARCIS (Netherlands)

Ozkan, E.; Houtum, van G.J.J.A.N.; Serin, Y.

2015-01-01

We consider the inventory control of repairable spare parts in a network consisting of a central warehouse, a central repair facility, and multiple local warehouses. Demands for spare parts occur at the local warehouses. If a local warehouse is out of stock, then an arriving demand is satisfied by

The School Building Principal and Inventory Control: A Case for Computerization.

Science.gov (United States)

Stronge, James

1987-01-01

General and special purpose database programs are appropriate for inventory control at the school building level. A fixed asset equipment inventory example illustrates the feasibility of computerized inventory control. (MLF)

Controle de estoque de peças de reposição em local único: uma revisão da literatura Single location spare parts inventory control: the state of the art

Directory of Open Access Journals (Sweden)

José Roberto do Rego

2011-01-01

Full Text Available Estoques de peças de reposição atendem necessidades de manutenção e reparo de produtos de consumo, veículos, máquinas e equipamentos industriais, acarretando frequentemente altos custos de capital e forte impacto no nível de serviço aos clientes. A grande multiplicidade de componentes, com ciclos de vida mais curtos e baixas demandas dificultam a gestão destes estoques. Este artigo apresenta revisão da literatura sobre modelos de controle de estoques de peças de reposição em local único, abordando tanto a previsão de demanda quanto o controle de estoques nos diferentes estágios do ciclo de vida das peças. A partir do levantamento bibliográfico, identificam-se algumas lacunas referentes à decisão de estocagem ou não de um item, elaboração de pedidos iniciais e finais, na integração de modelos de previsão de demanda com o controle de estoque e também de estudos de caso na aplicação prática dos modelos.Spare parts inventory are needed for maintenance and repair of final products, vehicles, industrial machines and equipments, frequently requiring high investments and significantly affecting customer satisfaction. Inventory management is complex due to the large number of different items and low demands. This article presents a literature review on single location spare parts inventory control, embracing both demand forecasting techniques and inventory control decisions on the different life cycle stages. Overall, the literature review identified the following research opportunities on inventory management: criteria to decide to stock or not an item, how many to order in the first and the last batch, demand forecasting and inventory control models integration and case studies on real applications.

Materials control and accountability challenges associated with plutonium inventories

International Nuclear Information System (INIS)

Crawford, D.W.

1996-01-01

There are currently many initiatives underway within the Department of Energy (DOE) to safely and securely manage large plutonium inventories arising from weapons dismantlement, changing missions and facility operations. Plutonium inventory information is increasingly accessible to the public as a result of the secretary of energy's openness initiative. As a result, knowledge of these inventories and levels to which the department has accounted for and controlled these inventories, will be under increased scrutiny from a variety of interest groups. The quality of this accountability data and what this data means will greatly influence the public's perception of how the US is protecting its plutonium inventories. In addition, the department's safeguards program provides an essential basis for the application of International Atomic Energy Agency (IAEA) safeguards that, in addition to possibly other international control regimes, will be in place over a large portion of these future inventories. The capability and functionality of the department's nuclear safeguards program will be important contributors to the success of US programs for the responsible stewardship of these vast plutonium inventories. This paper discusses some of the challenges, in terms of specific issues relating to one part of the department's safeguards program--materials control and accountability (MC and A)--to meet the growing domestic and international requirements and expectations associated with these plutonium inventories

Materials control and accountability challenges associated with plutonium inventories

Energy Technology Data Exchange (ETDEWEB)

Crawford, D.W. [USDOE Office of Safeguards and Security, Washington, DC (United States)

1996-07-01

There are currently many initiatives underway within the Department of Energy (DOE) to safely and securely manage large plutonium inventories arising from weapons dismantlement, changing missions and facility operations. Plutonium inventory information is increasingly accessible to the public as a result of the secretary of energy`s openness initiative. As a result, knowledge of these inventories and levels to which the department has accounted for and controlled these inventories, will be under increased scrutiny from a variety of interest groups. The quality of this accountability data and what this data means will greatly influence the public`s perception of how the US is protecting its plutonium inventories. In addition, the department`s safeguards program provides an essential basis for the application of International Atomic Energy Agency (IAEA) safeguards that, in addition to possibly other international control regimes, will be in place over a large portion of these future inventories. The capability and functionality of the department`s nuclear safeguards program will be important contributors to the success of US programs for the responsible stewardship of these vast plutonium inventories. This paper discusses some of the challenges, in terms of specific issues relating to one part of the department`s safeguards program--materials control and accountability (MC and A)--to meet the growing domestic and international requirements and expectations associated with these plutonium inventories.

Can investor sentiment be used to predict the stock price? Dynamic analysis based on China stock market

Science.gov (United States)

Guo, Kun; Sun, Yi; Qian, Xin

2017-03-01

With the development of the social network, the interaction between investors in stock market became more fast and convenient. Thus, investor sentiment which can influence their investment decisions may be quickly spread and magnified through the network, and to a certain extent the stock market can be affected. This paper collected the user comments data from a popular professional social networking site of China stock market called Xueqiu, then the investor sentiment data can be obtained through semantic analysis. The dynamic analysis on relationship between investor sentiment and stock market is proposed based on Thermal Optimal Path (TOP) method. The results show that the sentiment data was not always leading over stock market price, and it can be used to predict the stock price only when the stock has high investor attention.

An inventory control model for biomass dependent production systems

International Nuclear Information System (INIS)

Grado, S.C.; Strauss, C.H.

1993-01-01

The financial performance of a biomass dependent production system was critiqued based on the development and validation of an inventory control model. Dynamic programming was used to examine the constraints and capabilities of producing ethanol from various biomass crops. In particular, the model evaluated the plantation, harvest, and manufacturing components of a woody biomass supply system. The optimum wood to ethanol production scheme produced 38 million litres of ethanol in the harvest year, at 13.6 million litre increase over the least optimal policy as demonstrated in the dynamic programming results. The system produced ethanol at a delivered cost of $0.38 L -1 which was consistent with the unit costs from other studies. Nearly 60% of the delivered costs were in ethanol production. The remaining costs were attributed to growing biomass (14%), harvest and shipment of the crop (18%), storage of the raw material and finished product (7%) and open-quotes lost salesclose quotes (2%). Inventory control, in all phases of production, proved to be an important cost consideration throughout the model. The model also analyzed the employment of alternative harvesting policies and the use of different or multiple feedstocks. A comparison between the least cost wood system and an even cut wood system further revealed the benefits of using an inventory control system

An Improved Inventory Control Model for the Brazilian Navy Supply System

Science.gov (United States)

2001-12-01

Portuguese Centro de Controle de Inventario da Marinha, the Brazilian Navy Inventory Control Point (ICP) developed an empirical model called SPAADA...NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS Approved for public release; distribution is unlimited AN IMPROVED INVENTORY CONTROL ...AN IMPROVED INVENTORY CONTROL MODEL FOR THE BRAZILIAN NAVY SUPPLY SYSTEM Contract Number Grant Number Program Element Number Author(s) Moreira

VOCs emission characteristics and priority control analysis based on VOCs emission inventories and ozone formation potentials in Zhoushan

Science.gov (United States)

Wang, Qiaoli; Li, Sujing; Dong, Minli; Li, Wei; Gao, Xiang; Ye, Rongmin; Zhang, Dongxiao

2018-06-01

Zhoushan is an island city with booming tourism and service industry, but also has many developed VOCs and/or NOX emission industries. It is necessary to carry out regional VOCs and O3 pollution control in Zhoushan as the only new area owns the provincial economic and social administration rights. Anthropogenic VOCs emission inventories were built based on emission factor method and main emission sources were identified according to the emission inventories. Then, localized VOCs source profiles were built based on in-site sampling and referring to other studies. Furthermore, ozone formation potentials (OFPs) profiles were built through VOCs source profiles and maximum incremental reactivity (MIR) theory. At last, the priority control analysis results showed that industrial processes, especially surface coating, are the key of VOCs and O3 control. Alkanes were the most emitted group, accounting for 58.67%, while aromatics contributed the most to ozone production accounting for 69.97% in total OFPs. n-butane, m/p-xylene, i-pentane, n-decane, toluene, propane, n-undecane, o-xylene, methyl cyclohexane and ethyl benzene were the top 10 VOC species that should be preferentially controlled for VOCs emission control. However, m/p-xylene, o-xylene, ethylene, n-butane, toluene, propene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, ethyl benzene and 1,2,3-trimethyl benzene were the top 10 VOC species that required preferential control for O3 pollution control.

Scaling impacts on environmental controls and spatial heterogeneity of soil organic carbon stocks

Science.gov (United States)

Mishra, U.; Riley, W. J.

2015-07-01

The spatial heterogeneity of land surfaces affects energy, moisture, and greenhouse gas exchanges with the atmosphere. However, representing the heterogeneity of terrestrial hydrological and biogeochemical processes in Earth system models (ESMs) remains a critical scientific challenge. We report the impact of spatial scaling on environmental controls, spatial structure, and statistical properties of soil organic carbon (SOC) stocks across the US state of Alaska. We used soil profile observations and environmental factors such as topography, climate, land cover types, and surficial geology to predict the SOC stocks at a 50 m spatial scale. These spatially heterogeneous estimates provide a data set with reasonable fidelity to the observations at a sufficiently high resolution to examine the environmental controls on the spatial structure of SOC stocks. We upscaled both the predicted SOC stocks and environmental variables from finer to coarser spatial scales (s = 100, 200, and 500 m and 1, 2, 5, and 10 km) and generated various statistical properties of SOC stock estimates. We found different environmental factors to be statistically significant predictors at different spatial scales. Only elevation, temperature, potential evapotranspiration, and scrub land cover types were significant predictors at all scales. The strengths of control (the median value of geographically weighted regression coefficients) of these four environmental variables on SOC stocks decreased with increasing scale and were accurately represented using mathematical functions (R2 = 0.83-0.97). The spatial structure of SOC stocks across Alaska changed with spatial scale. Although the variance (sill) and unstructured variability (nugget) of the calculated variograms of SOC stocks decreased exponentially with scale, the correlation length (range) remained relatively constant across scale. The variance of predicted SOC stocks decreased with spatial scale over the range of 50 m to ~ 500 m, and remained

10 CFR 74.43 - Internal controls, inventory, and records.

Science.gov (United States)

2010-01-01

..., inventory, and recordkeeping capabilities required in paragraphs (b), (c), and (d) of this section. (b...) Provides current knowledge of SNM items with respect to identity, element and isotope content, and stored... measurements for the licensee. (c) Inventory control and physical inventories. The licensee shall: (1) Provide...

The impact of decentralised control on firm-level inventory: evidence from the automotive industry

NARCIS (Netherlands)

de Leeuw, S.L.J.M.; Holweg, M.; Williams, G.

2011-01-01

Purpose: The purpose of this paper is to investigate the effect of decentralised control on finished goods inventory levels in a distribution system, and to identify the factors that determine the overall inventory level. Design/methodology/approach: The authors' study is based on a mixed method

Detecting small-scale spatial heterogeneity and temporal dynamics of soil organic carbon (SOC) stocks: a comparison between automatic chamber-derived C budgets and repeated soil inventories

Science.gov (United States)

Hoffmann, Mathias; Jurisch, Nicole; Garcia Alba, Juana; Albiac Borraz, Elisa; Schmidt, Marten; Huth, Vytas; Rogasik, Helmut; Rieckh, Helene; Verch, Gernot; Sommer, Michael; Augustin, Jürgen

2017-03-01

Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (ΔSOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial (10-30 m) and temporal changes in SOC stocks, particularly pronounced in arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in ΔSOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal ΔSOC patterns but lack small-scale spatial resolution. To overcome these limitations, this study presents a reliable method to detect both short-term temporal dynamics as well as small-scale spatial differences of ΔSOC using measurements of the net ecosystem carbon balance (NECB) as a proxy. To estimate the NECB, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot) were used. To verify our method, results were compared with ΔSOC observed by soil resampling. Soil resampling and AC measurements were performed from 2010 to 2014 at a colluvial depression located in the hummocky ground moraine landscape of northeastern Germany. The measurement site is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity regarding SOC and nitrogen (Nt) stocks. Tendencies and magnitude of ΔSOC values derived by AC measurements and repeated soil inventories corresponded well. The period of maximum plant growth was identified as being most important for the development of spatial differences in annual ΔSOC. Hence, we were able to confirm that AC-based C budgets are able

A Control Systems Concept Inventory Test Design and Assessment

Science.gov (United States)

Bristow, M.; Erkorkmaz, K.; Huissoon, J. P.; Jeon, Soo; Owen, W. S.; Waslander, S. L.; Stubley, G. D.

2012-01-01

Any meaningful initiative to improve the teaching and learning in introductory control systems courses needs a clear test of student conceptual understanding to determine the effectiveness of proposed methods and activities. The authors propose a control systems concept inventory. Development of the inventory was collaborative and iterative. The…

Estimating agro-ecosystem carbon balance of northern Japan, and comparing the change in carbon stock by soil inventory and net biome productivity

Energy Technology Data Exchange (ETDEWEB)

Li, Xi, E-mail: icy124@hotmail.com [School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Graduate school of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo 060-8589 (Japan); Toma, Yo [Faculty of Agriculture, Ehime University, 3-5-7, Tarumi, Matsuyama 790-8566, Ehime (Japan); Yeluripati, Jagadeesh [The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, Scotland (United Kingdom); Iwasaki, Shinya [Graduate school of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo 060-8589 (Japan); Bellingrath-Kimura, Sonoko D. [Leibniz Centre for Agricultural Landscape Research, Institute of Land Use Systems (Germany); Jones, Edward O. [Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London (United Kingdom); Hatano, Ryusuke [Graduate school of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo 060-8589 (Japan)

2016-06-01

Soil C sequestration in croplands is deemed to be one of the most promising greenhouse gas mitigation options for agriculture. We have used crop-level yields, modeled heterotrophic respiration (Rh) and land use data to estimate spatio-temporal changes in regional scale net primary productivity (NPP), plant C inputs, and net biome productivity (NBP) in northern Japan's arable croplands and grasslands for the period of 1959–2011. We compared the changes in C stocks derived from estimated NBP and using repeated inventory datasets for each individual land use type from 2005 to 2011. For the entire study region of 2193 ha, overall annual plant C inputs to the soil constituted 37% of total region NPP. Plant C inputs in upland areas (excluding bush/fallow) could be predicted by climate variables. Overall NBP for all land use types increased from − 1.26 Mg C ha{sup −1} yr{sup −1} in 1959–0.26 Mg C ha{sup −1} yr{sup −1} in 2011. However, upland and paddy fields showed a decreased in NBP over the period of 1959–2011, under the current C input scenario. From 1988, an increase in agricultural abandonment (bush/fallow) and grassland cover caused a slow increase in the regional C pools. The comparison of carbon budgets using the NBP estimation method and the soil inventory method indicated no significant difference between the two methods. Our results showed C loss in upland crops, paddy fields and sites that underwent land use change from paddy field to upland sites. We also show C gain in grassland from 2005 to 2011. An underestimation of NBP or an overestimation of repeated C inventories cannot be excluded, but either method may be suitable for tracking absolute changes in soil C, considering the uncertainty associated with these methods. - Highlights: • We compared C stocks change by two methods: (i) net biome productivity (NBP) and (ii) soil inventory. • Variation in net primary productivity (NPP), plant C input, NBP can be predicted by climate

Estimating agro-ecosystem carbon balance of northern Japan, and comparing the change in carbon stock by soil inventory and net biome productivity

International Nuclear Information System (INIS)

Li, Xi; Toma, Yo; Yeluripati, Jagadeesh; Iwasaki, Shinya; Bellingrath-Kimura, Sonoko D.; Jones, Edward O.; Hatano, Ryusuke

2016-01-01

Soil C sequestration in croplands is deemed to be one of the most promising greenhouse gas mitigation options for agriculture. We have used crop-level yields, modeled heterotrophic respiration (Rh) and land use data to estimate spatio-temporal changes in regional scale net primary productivity (NPP), plant C inputs, and net biome productivity (NBP) in northern Japan's arable croplands and grasslands for the period of 1959–2011. We compared the changes in C stocks derived from estimated NBP and using repeated inventory datasets for each individual land use type from 2005 to 2011. For the entire study region of 2193 ha, overall annual plant C inputs to the soil constituted 37% of total region NPP. Plant C inputs in upland areas (excluding bush/fallow) could be predicted by climate variables. Overall NBP for all land use types increased from − 1.26 Mg C ha"−"1 yr"−"1 in 1959–0.26 Mg C ha"−"1 yr"−"1 in 2011. However, upland and paddy fields showed a decreased in NBP over the period of 1959–2011, under the current C input scenario. From 1988, an increase in agricultural abandonment (bush/fallow) and grassland cover caused a slow increase in the regional C pools. The comparison of carbon budgets using the NBP estimation method and the soil inventory method indicated no significant difference between the two methods. Our results showed C loss in upland crops, paddy fields and sites that underwent land use change from paddy field to upland sites. We also show C gain in grassland from 2005 to 2011. An underestimation of NBP or an overestimation of repeated C inventories cannot be excluded, but either method may be suitable for tracking absolute changes in soil C, considering the uncertainty associated with these methods. - Highlights: • We compared C stocks change by two methods: (i) net biome productivity (NBP) and (ii) soil inventory. • Variation in net primary productivity (NPP), plant C input, NBP can be predicted by climate conditions. • NBP

Components of Inventory Change (CINCH) Reports

Data.gov (United States)

Department of Housing and Urban Development — The Components of Inventory Change (CINCH) report measures changes in the characteristics of the housing stock of the United States. Using data collected from the...

A Stock Trading Recommender System Based on Temporal Association Rule Mining

Directory of Open Access Journals (Sweden)

Binoy B. Nair

2015-04-01

Full Text Available Recommender systems capable of discovering patterns in stock price movements and generating stock recommendations based on the patterns thus discovered can significantly supplement the decision-making process of a stock trader. Such recommender systems are of great significance to a layperson who wishes to profit by stock trading even while not possessing the skill or expertise of a seasoned trader. A genetic algorithm optimized Symbolic Aggregate approXimation (SAX–Apriori based stock trading recommender system, which can mine temporal association rules from the stock price data set to generate stock trading recommendations, is presented in this article. The proposed system is validated on 12 different data sets. The results indicate that the proposed system significantly outperforms the passive buy-and-hold strategy, offering scope for a layperson to successfully invest in capital markets.

[Optimization of inventory levels in the blood transfusion centers in Morocco].

Science.gov (United States)

Bellabdaoui, A; Bennis, I; Saadi, J; Benajiba, M

2014-03-01

Improve the flow of quantities of blood products between the different centers to restore the ideal quantities at low cost. The problem addressed in this work concerns the balancing inventory levels between blood transfusion centers in Morocco. This problem is characterized by a number of constraints to be taken into account: safety stock, stock ideal proportional balancing of stocks, etc. An integer linear model has been proposed to determine the optimal allocation between different centers. Two variants are examined; the first which aims to minimize the level of inventory loss, the second is to balance the different levels of stock, so that all centers have a level of surplus stock and/or loss proportional to the ideal stock. Two variants of an integer linear model that determine the optimal allocation between different centers has been proposed and their performance was evaluated by experimental results obtained using a solver commercial. The results of this study allow us to meet the goal of PSL availability of sufficient and subsequently the quality of service required blood transfusion. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

The Differences Between Stock Splits and Stock Dividends

DEFF Research Database (Denmark)

Bechmann, Ken L.; Raaballe, Johannes

It is often asserted that stock splits and stock dividends are purely cosmetic events. However, many studies have documented several stock market effects associated with stock splits and stock dividends. This paper examines the effects of these two types of events for the Danish stock market...... different. Second, the positive stock market reaction is closely related to associated changes in a firm's payout policy, but the relationship varies for the two types of events. Finally, there is only very weak evidence for a change in the liquidity of the stock. On the whole, after controlling...... for the firm's payout policy, the results suggest that a stock split is a cosmetic event and that a stock dividend on its own is considered negative news....

Government grant control of development of stock-raising

OpenAIRE

SAMOYLIK YU.V.

2012-01-01

Directions of improvement of mechanism of government grant control of development of stock-raising are offered on the basis of the educed tendencies and conformities to law in the existent system of sponsorship of industry.

Control system implementation for a complex low inventory cryogenic distillation system for Princeton TFTR

International Nuclear Information System (INIS)

Busigin, A.; Busigin, C.J.; Adamek, F.; Woodall, K.B.; Robins, J.R.; Bellamy, D.G.; Fong, C.; Kalyanam, K.M.; Sood, S.K.

1995-01-01

The TFTR Tritium Purification System (TPS) is based on a Pd/Ag diffuser front-end for separating hydrogen isotopes from inert gas, and a four column cryogenic distillation cascade for separation of hydrogen isotopes. The system has a tritium inventory of approximately 0.5 g while successfully producing pure H 2 , D 2 and T 2 products. The system has recently been built and successfully commissioned with protium and deuterium. Stable automatic control of the cascade has been demonstrated even when feed rate and composition varied. The automatic control scheme maintained stable column inventories and excellent H 2 and D 2 product qualities. The control system employed new control concepts such as real time analysis of mid-column composition using temperature and pressure data for feedback control. Very stable column inventory control was achieved by automatic adjustment of inter-column flows (feed forward and feed back). This paper discusses the control system design and presents performance test results. (orig.)

Sensitivity of TRIM projections to management, harvest, yield, and stocking adjustment assumptions.

Science.gov (United States)

Susan J. Alexander

1991-01-01

The Timber Resource Inventory Model (TRIM) was used to make several projections of forest industry timber supply for the Douglas-fir region. The sensitivity of these projections to assumptions about management and yields is discussed. A base run is compared to runs in which yields were altered, stocking adjustment was eliminated, harvest assumptions were changed, and...

Recent advances of rearing cabinet instrumentation and control system for insect stock culture

Science.gov (United States)

Hermawan, Wawan; Kasmara, Hikmat; Melanie, Panatarani, Camellia; Joni, I. Made

2017-01-01

Helicoverpa armigera (Hubner) is one of a serious pest of horticulture in Indonesia. Helicoverpa armigera Nuclear Polyhedrovirus (HaNPV) has attracted interest for many researchers as a pest control for larvae of this species. Currently, we investigating the agrochemical formulations of HaNPV by introducing nanotechnology. Thus it is required an acceptable efficiency of insect stock cultures equipped with advance instruments to resolve the difficulties on insect stock seasons dependency. In addition, it is important to improve the insect survival with the aid of artificial natural environment and gain high insect production. This paper reports the rearing cabinet used as preparation of stock culture includes air-conditioning system, lighting, i.e. day and night control, and the main principles on recent technical and procedural advances apparatus of the system. The rearing system was moveable, designed and build by allowing air-conditioned cabinet for rearing insects, air motion and distribution as well as temperature and humidity being precisely controlled. The air was heated, humidified, and dehumidified respectively using a heater and ultrasonic nebulizer as actuators. Temperature and humidity can be controlled at any desired levels from room temperature (20°C) to 40 ± 1°C and from 0 to 80% RH with an accuracy of ±3% R.H. It is concluded that the recent design has acceptable performance based on the defined requirement for insect rearing and storage.

Monitoring and estimating tropical forest carbon stocks: making REDD a reality

International Nuclear Information System (INIS)

Gibbs, Holly K; Brown, Sandra; Niles, John O; Foley, Jonathan A

2007-01-01

Reducing carbon emissions from deforestation and degradation in developing countries is of central importance in efforts to combat climate change. Key scientific challenges must be addressed to prevent any policy roadblocks. Foremost among the challenges is quantifying nations' carbon emissions from deforestation and forest degradation, which requires information on forest clearing and carbon storage. Here we review a range of methods available to estimate national-level forest carbon stocks in developing countries. While there are no practical methods to directly measure all forest carbon stocks across a country, both ground-based and remote-sensing measurements of forest attributes can be converted into estimates of national carbon stocks using allometric relationships. Here we synthesize, map and update prominent forest biomass carbon databases to create the first complete set of national-level forest carbon stock estimates. These forest carbon estimates expand on the default values recommended by the Intergovernmental Panel on Climate Change's National Greenhouse Gas Inventory Guidelines and provide a range of globally consistent estimates

Inventorying Toronto's single detached housing stocks to examine the availability of clay brick for urban mining.

Science.gov (United States)

Ergun, Deniz; Gorgolewski, Mark

2015-11-01

This study examines the stocks of clay brick in Toronto's single detached housing, to provide parameters for city scale material reuse and recycling. Based on consensus from the literature and statistics on Toronto's single detached housing stocks, city scale reusable and recyclable stocks were estimated to provide an understanding of what volume could be saved from landfill and reintroduced into the urban fabric. On average 2523-4542 m(3) of brick was determined to be available annually for reuse, which would account for 20-36% of the volume of virgin brick consumed in new house construction in 2012. A higher volume, 6187 m(3) of brick, was determined to be available annually for recycling because more of the prevalence of cement-based mortar, which creates challenges for brick reuse in Toronto. The results demonstrated that older housing containing reusable brick were being mostly landfilled and replaced with housing that contained only recyclable brick. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inventory-based estimates of forest biomass carbon stocks in China: A comparison of three methods

Science.gov (United States)

Zhaodi Guo; Jingyun Fang; Yude Pan; Richard. Birdsey

2010-01-01

Several studies have reported different estimates for forest biomass carbon (C) stocks in China. The discrepancy among these estimates may be largely attributed to the methods used. In this study, we used three methods [mean biomass density method (MBM), mean ratio method (MRM), and continuous biomass expansion factor (BEF) method (abbreviated as CBM)] applied to...

National inventory of radioactive wastes and valorizable materials. Synthesis report

International Nuclear Information System (INIS)

2004-01-01

This national inventory of radioactive wastes is a reference document for professionals and scientists of the nuclear domain and also for any citizen interested in the management of radioactive wastes. It contains: 1 - general introduction; 2 - the radioactive wastes: definition, classification, origin and management; 3 - methodology of the inventory: organization, accounting, prospective, production forecasting, recording of valorizable materials, exhaustiveness, verification tools; 4 - general results: radioactive waste stocks recorded until December 31, 2002, forecasts for the 2003-2020 era, post-2020 prospects: dismantling operations, recording of valorizable materials; 5 - inventory per producer or owner: front-end fuel cycle facilities, power generation nuclear centers, back-end fuel cycle facilities, waste processing or maintenance facilities, civil CEA research centers, non-CEA research centers, medical activities (diagnostics, therapeutics, analyses), various industrial activities (sources fabrication, control, particular devices), military research and experiment centers, storage and disposal facilities; 6 - elements about radioactive polluted sites; 7 - examples of foreign inventories; 8 - conclusion and appendixes. (J.S.)

Speciated OVOC and VOC emission inventories and their implications for reactivity-based ozone control strategy in the Pearl River Delta region, China.

Science.gov (United States)

Ou, Jiamin; Zheng, Junyu; Li, Rongrong; Huang, Xiaobo; Zhong, Zhuangmin; Zhong, Liuju; Lin, Hui

2015-10-15

The increasing ground-ozone (O3) levels, accompanied by decreasing SO2, NO2, PM10 and PM2.5 concentrations benefited from air pollution control measures implemented in recent years, initiated a serious challenge to control Volatile Organic Compound (VOC) emissions in the Pearl River Delta (PRD) region, China. Speciated VOC emission inventory is fundamental for estimating Ozone Formation Potentials (OFPs) to identify key reactive VOC species and sources in order to formulate efficient O3 control strategies. With the use of the latest bulk VOC emission inventory and local source profiles, this study developed the PRD regional speciated Oxygenated Volatile Organic Compound (OVOC) and VOC emission inventories to identify the key emission-based and OFP-based VOC sources and species. Results showed that: (1) Methyl alcohol, acetone and ethyl acetate were the major constituents in the OVOC emissions from industrial solvents, household solvents, architectural paints and biogenic sources; (2) from the emission-based perspective, aromatics, alkanes, OVOCs and alkenes made up 39.2%, 28.2%, 15.9% and 10.9% of anthropogenic VOCs; (3) from the OFP-based perspective, aromatics and alkenes become predominant with contributions of 59.4% and 25.8% respectively; (4) ethene, m/p-xylene, toluene, 1,2,4-trimethyl benzene and other 24 high OFP-contributing species were the key reactive species that contributed to 52% of anthropogenic emissions and up to 80% of OFPs; and (5) industrial solvents, industrial process, gasoline vehicles and motorcycles were major emission sources of these key reactive species. Policy implications for O3 control strategy were discussed. The OFP cap was proposed to regulate VOC control policies in the PRD region due to its flexibility in reducing the overall OFP of VOC emission sources in practice. Copyright © 2015 Elsevier B.V. All rights reserved.

AN ASSESSMENT OF FACTORS AFFECTING MATERIAL STOCK CONTROL PRACTICE ON SELECTED CONSTRUCTION SITES IN NIGERIA

OpenAIRE

Adafin, Johnson Kayode; Ayodele, Elijah Olusegun; Daramola, Olufemi

2011-01-01

This research examines the stock control methods utilized by construction firms on construction sites with a view to assessing the factors affecting material stock control practice by construction firms as well as determining the impact of factors affecting material stock control on building project performance. Data were collected with the aid of well-structured questionnaire administered on a number of construction professionals and technicians in some randomly selected building constructio...

26 CFR 48.6412-1 - Floor stocks credit or refund.

Science.gov (United States)

2010-04-01

...; and (D) The quantity of articles held by the dealer as floor stocks on the inventory date. (3) Actual... Revenue Code of 1954 with respect to the articles in my inventory on _____. (Name) By (Signature of... refund authorized by section 6412 for manufacturers excise taxes paid in respect of certain articles held...

Base-stock policies with reservations

NARCIS (Netherlands)

van Foreest, Nicky D.; Teunter, Ruud H.; Syntetos, Aris A.

2018-01-01

All intensively studied and widely applied inventory control policies satisfy demand in accordance with the First-Come-First-Served (FCFS) rule, whether this demand is in backorder or not. Interestingly, this rule is sub-optimal when the fill-rate is constrained or when the backorder cost structure

Agricultural management explains historic changes in regional soil carbon stocks

Science.gov (United States)

van Wesemael, Bas; Paustian, Keith; Meersmans, Jeroen; Goidts, Esther; Barancikova, Gabriela; Easter, Mark

2010-01-01

Agriculture is considered to be among the economic sectors having the greatest greenhouse gas mitigation potential, largely via soil organic carbon (SOC) sequestration. However, it remains a challenge to accurately quantify SOC stock changes at regional to national scales. SOC stock changes resulting from SOC inventory systems are only available for a few countries and the trends vary widely between studies. Process-based models can provide insight in the drivers of SOC changes, but accurate input data are currently not available at these spatial scales. Here we use measurements from a soil inventory dating from the 1960s and resampled in 2006 covering the major soil types and agricultural regions in Belgium together with region-specific land use and management data and a process-based model. The largest decreases in SOC stocks occurred in poorly drained grassland soils (clays and floodplain soils), consistent with drainage improvements since 1960. Large increases in SOC in well drained grassland soils appear to be a legacy effect of widespread conversion of cropland to grassland before 1960. SOC in cropland increased only in sandy lowland soils, driven by increasing manure additions. Modeled land use and management impacts accounted for more than 70% of the variation in observed SOC changes, and no bias could be demonstrated. There was no significant effect of climate trends since 1960 on observed SOC changes. SOC monitoring networks are being established in many countries. Our results demonstrate that detailed and long-term land management data are crucial to explain the observed SOC changes for such networks. PMID:20679194

Detecting small-scale spatial differences and temporal dynamics of soil organic carbon (SOC) stocks: a comparison between automatic chamber-derived C budgets and repeated soil inventories

Science.gov (United States)

Hoffmann, Mathias; Jurisch, Nicole; Garcia Alba, Juana; Albiac Borraz, Elisa; Schmidt, Marten; Huth, Vytas; Rogasik, Helmut; Rieckh, Helene; Verch, Gernot; Sommer, Michael; Augustin, Jürgen

2017-04-01

Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (ΔSOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial and temporal changes in SOC stocks, particularly pronounced on arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in ΔSOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal ΔSOC patterns but lack small-scale spatial resolution. To overcome these limitations, this study presents a reliable method to detect both short-term temporal as well as small-scale spatial dynamics of ΔSOC. Therefore, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot) was used. To verify our method, results were compared with ΔSOC observed by soil resampling. AC measurements were performed from 2010 to 2014 under a silage maize/winter fodder rye/sorghum-Sudan grass hybrid/alfalfa crop rotation at a colluvial depression located in the hummocky ground moraine landscape of NE Germany. Widespread in large areas of the formerly glaciated Northern Hemisphere, this depression type is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity in soil properties, such as SOC and nitrogen (Nt). After monitoring the initial stage during 2010, soil erosion was experimentally simulated by incorporating topsoil material from an eroded midslope soil into the plough layer of the colluvial depression. SOC stocks were quantified before and after soil manipulation and at the end

Employing imperfect advance demand information in ordering and inventory rationing decisions

NARCIS (Netherlands)

Tan, T.; Güllü, R.; Erkip, N.

2009-01-01

In this paper, we consider an inventory problem with two demand classes having different priorities. The appropriate policy of rationing the available stock, i.e. reserving some stock for meeting prospective future demand of preferred customers at the expense of deliberately losing some of the

STOCK Market Differences in Correlation-Based Weighted Network

Science.gov (United States)

Youn, Janghyuk; Lee, Junghoon; Chang, Woojin

We examined the sector dynamics of Korean stock market in relation to the market volatility. The daily price data of 360 stocks for 5019 trading days (from January, 1990 to August, 2008) in Korean stock market are used. We performed the weighted network analysis and employed four measures: the average, the variance, the intensity, and the coherence of network weights (absolute values of stock return correlations) to investigate the network structure of Korean stock market. We performed regression analysis using the four measures in the seven major industry sectors and the market (seven sectors combined). We found that the average, the intensity, and the coherence of sector (subnetwork) weights increase as market becomes volatile. Except for the "Financials" sector, the variance of sector weights also grows as market volatility increases. Based on the four measures, we can categorize "Financials," "Information Technology" and "Industrials" sectors into one group, and "Materials" and "Consumer Discretionary" sectors into another group. We investigated the distributions of intrasector and intersector weights for each sector and found the differences in "Financials" sector are most distinct.

Knowledge as Inventory: Near-Optimizing Knowledge and Power Flows in Edge Organizations (Phase One)

National Research Council Canada - National Science Library

MacKinnon, Douglas J

2005-01-01

.... We hypothesize that analyzing the stocks and flows of perishable knowledge inventory" in organizations, analogous to analyzing those of perishable physical goods inventory in a supply chain, uncovers...

National inventory of the radioactive wastes and the recycling materials; Inventaire national des dechets radioactifs et des matieres valorisables

Energy Technology Data Exchange (ETDEWEB)

Dupuis, M.C

2006-07-01

This synthesis report presents the 2006 inventory of the radioactive wastes and recycling materials, in France. It contains 9 chapters: a general introduction, the radioactive wastes (definition, classification, origins and management), the inventory methodology (organization, accounting and prospecting, exhaustiveness and control tools), main results (stocks, prevision for the period 2005-2020, perspectives after 2020), the inventory for producers or owners (front end fuel cycle, electric power plants, back end fuel cycle, wastes processing and maintenance facilities, researches centers, medical activities, industrial activities, non nuclear industries using nuclear materials, defense center, storage and disposal), the polluted sites, examples of foreign inventories, conclusion and annexes. (A.L.B.)

Optimization and Customer Utilities under Dynamic Lead Time Quotation in an M/M Type Base Stock System

Directory of Open Access Journals (Sweden)

Koichi Nakade

2017-01-01

Full Text Available In a manufacturing and inventory system, information on production and order lead time helps consumers’ decision whether they receive finished products or not by considering their own impatience on waiting time. In Savaşaneril et al. (2010, the optimal dynamic lead time quotation policy in a one-stage production and inventory system with a base stock policy for maximizing the system’s profit and its properties are discussed. In this system, each arriving customer decides whether he/she enters the system based on the quoted lead time informed by the system. On the other hand, the customer’s utility may be small under the optimal quoted lead time policy because the actual lead time may be longer than the quoted lead time. We use a utility function with respect to benefit of receiving products and waiting time and propose several kinds of heuristic lead time quotation policies. These are compared with optimal policies with respect to both profits and customer’s utilities. Through numerical examples some kinds of heuristic policies have better expected utilities of customers than the optimal quoted lead time policy maximizing system’s profits.

A framework for assessing global change risks to forest carbon stocks in the United States.

Directory of Open Access Journals (Sweden)

Christopher W Woodall

Full Text Available Among terrestrial environments, forests are not only the largest long-term sink of atmospheric carbon (C, but are also susceptible to global change themselves, with potential consequences including alterations of C cycles and potential C emission. To inform global change risk assessment of forest C across large spatial/temporal scales, this study constructed and evaluated a basic risk framework which combined the magnitude of C stocks and their associated probability of stock change in the context of global change across the US. For the purposes of this analysis, forest C was divided into five pools, two live (aboveground and belowground biomass and three dead (dead wood, soil organic matter, and forest floor with a risk framework parameterized using the US's national greenhouse gas inventory and associated forest inventory data across current and projected future Köppen-Geiger climate zones (A1F1 scenario. Results suggest that an initial forest C risk matrix may be constructed to focus attention on short- and long-term risks to forest C stocks (as opposed to implementation in decision making using inventory-based estimates of total stocks and associated estimates of variability (i.e., coefficient of variation among climate zones. The empirical parameterization of such a risk matrix highlighted numerous knowledge gaps: 1 robust measures of the likelihood of forest C stock change under climate change scenarios, 2 projections of forest C stocks given unforeseen socioeconomic conditions (i.e., land-use change, and 3 appropriate social responses to global change events for which there is no contemporary climate/disturbance analog (e.g., severe droughts in the Lake States. Coupling these current technical/social limits of developing a risk matrix to the biological processes of forest ecosystems (i.e., disturbance events and interaction among diverse forest C pools, potential positive feedbacks, and forest resiliency/recovery suggests an operational

A forward-looking, national-scale remote sensing-based model of tidal marsh aboveground carbon stocks

Science.gov (United States)

Holmquist, J. R.; Byrd, K. B.; Ballanti, L.; Nguyen, D.; Simard, M.; Windham-Myers, L.; Thomas, N.

2017-12-01

Remote sensing based maps of tidal marshes, both of their extents and carbon stocks, have the potential to play a key role in conducting greenhouse gas inventories and implementing climate mitigation policies. Our goal was to generate a single remote sensing model of tidal marsh aboveground biomass and carbon that represents nationally diverse tidal marshes within the conterminous United States (CONUS). To meet this objective we developed the first national-scale dataset of aboveground tidal marsh biomass, species composition, and aboveground plant carbon content (%C) from six CONUS regions: Cape Cod, MA, Chesapeake Bay, MD, Everglades, FL, Mississippi Delta, LA, San Francisco Bay, CA, and Puget Sound, WA. Using the random forest algorithm we tested Sentinel-1 radar backscatter metrics and Landsat vegetation indices as predictors of biomass. The final model, driven by six Landsat vegetation indices and with the soil adjusted vegetation index as the most important (n=409, RMSE=310 g/m2, 10.3% normalized RMSE), successfully predicted biomass and carbon for a range of marsh plant functional types defined by height, leaf angle and growth form. Model error was reduced by scaling field measured biomass by Landsat fraction green vegetation derived from object-based classification of National Agriculture Imagery Program imagery. We generated 30m resolution biomass maps for estuarine and palustrine emergent tidal marshes as indicated by a modified NOAA Coastal Change Analysis Program map for each region. With a mean plant %C of 44.1% (n=1384, 95% C.I.=43.99% - 44.37%) we estimated mean aboveground carbon densities (Mg/ha) and total carbon stocks for each wetland type for each region. Louisiana palustrine emergent marshes had the highest C density (2.67 ±0.08 Mg/ha) of all regions, while San Francisco Bay brackish/saline marshes had the highest C density of all estuarine emergent marshes (2.03 ±0.06 Mg/ha). This modeling and data synthesis effort will allow for aboveground

Estimating dead wood during national forest inventories: a review of inventory methodologies and suggestions for harmonization.

Science.gov (United States)

Woodall, Christopher W; Rondeux, Jacques; Verkerk, Pieter J; Ståhl, Göran

2009-10-01

Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world's forested landscapes is scattered. The goal of this study is to describe the status, DW components measured, sample methods employed, and DW component thresholds used by national forest inventories that currently inventory DW around the world. Study results indicate that most countries do not inventory forest DW. Globally, we estimate that about 13% of countries inventory DW using a diversity of sample methods and DW component definitions. A common feature among DW inventories was that most countries had only just begun DW inventories and employ very low sample intensities. There are major hurdles to harmonizing national forest inventories of DW: differences in population definitions, lack of clarity on sample protocols/estimation procedures, and sparse availability of inventory data/reports. Increasing database/estimation flexibility, developing common dimensional thresholds of DW components, publishing inventory procedures/protocols, releasing inventory data/reports to international peer review, and increasing communication (e.g., workshops) among countries inventorying DW are suggestions forwarded by this study to increase DW inventory harmonization.

Do More Economists Hold Stocks?

DEFF Research Database (Denmark)

Christiansen, Charlotte; Joensen, Juanna Schröter; Rangvid, Jesper

A unique data set enables us to test the hypothesis that more economists than otherwise identical investors hold stocks due to informational advantages. We confirm that economists have a significantly higher probability of participating in the stock market than investors with any other education......, even when controlling for several background characteristics. We make use of a large register-based panel data set containing detailed information on the educational attainments and various financial and socioeconomic variables. We model the stock market participation decision by the probit model...

Chemical inventory control program for mixed and hazardous waste facilities at SRS

International Nuclear Information System (INIS)

Ades, M.J.; Vincent, A.M. III.

1997-01-01

Mixed Waste (MW) and Hazardous Waste (HW) are being stored at the Savannah River Site (SRS) pending onsite and/or offsite treatment and disposal. The inventory control for these wastes has recently been brought under Technical Safety Requirements (TSR) in accordance with DOE Order 5480.22. With the TSRs was the question of the degree of rigor with which the inventory is to be tracked, considering that the variety of chemicals present, or that could be present, numbers in the hundreds. This paper describes the graded approach program to track Solid Waste (SW) inventories relative to TSRs. The approach uses a ratio of the maximum anticipated chemical inventory to the permissible inventory in accordance with Emergency Response Planning Guideline (ERPG) limits for on- and off-site receptors. A specific threshold ratio can then be determined. The chemicals above this threshold ratio are to be included in the chemical inventory control program. The chemicals that fall below the threshold ratio are managed in accordance with existing practice per State and RCRA hazardous materials requirements. Additionally, the facilities are managed in accordance with process safety management principles, specifically using process hazards analyses, which provides safety assurance for even the small quantities that may be excluded from the formal inventory control program. The method yields a practical approach to chemical inventory control, while maintaining appropriate chemical safety margins. The resulting number of specific chemicals that require inclusion in a rigorous inventory control program is greatly reduced by about 80%, thereby resulting in significant reduction in chemical data management while preserving appropriate safety margins

An organizational perspective on inventory control : Theory and a case study

NARCIS (Netherlands)

Zomerdijk, L.G.; de Vries, J.

2003-01-01

Inventory control is a well-covered area in literature. Nowadays, many concepts and techniques are available for effectively controlling inventories. Eminent examples are stochastic models to determine order quantities, techniques for forecasting demand and different kinds of ABC analysis.

Geohydrology of the climax stock granite and surrounding rock formations, NTS

International Nuclear Information System (INIS)

Murray, W.A.

1981-05-01

The location of the water table and the degree of saturation of the granitic rocks in the Climax stock are presently unknown. Based on existing knowledge and an extrapolation of available geohydrologic data, it appears that the water table may lie at about 1100 to 1200 m above mean sea level (MSL) in the northeastern part of the stock and at about 800 to 900 m in the southwest. A drilling program would be required to establish these levels precisely. The degree of saturation at a given underground elevation may be approximated by a detailed inventory of seeps at that level. More precise determination of degree of saturation will require a water budet. 27 figures, 2 tables

Study on inventory control model based on the B2C mode in big data environment

Directory of Open Access Journals (Sweden)

Zhiping Zhang

2017-03-01

Full Text Available The current inventory problem has become the key issue in the enterprise survival and development. In this paper, we take “Taobao” as an example to conduct a detailed study of the inventory of the high conversion rate based on data mining. First, by using a funnel model to predict the conversion of the commodities on the critical path, we capture the factors influencing the consumer decision-making on each key point, and propose corresponding solutions of improving the conversion rate; Second, we use BP neural network algorithm to predict the goods traffic, and then obtain the corresponding weights by the relation analysis and the output of the goods traffic by the input of large data sample goods; Third, we can predict the inventory in accordance with the commodity conversion rate and flow prediction, and amend the predicted results to get accurate and real-time inventory forecast, avoiding the economic loss due to the inaccurate inventory.

The customer waiting time in an (R,s,Q) inventory system

NARCIS (Netherlands)

Kiesmüller, G.P.; Kok, de A.G.

2006-01-01

In practice of inventory management customer-oriented service measures play an important role. If inventory managers of stockpoints in a supply chain promise specific times of delivery that cannot be met due to a lack of stock, leadtimes at downstream stockpoints increase, causing substantial

Hanford regulated laundry: inventory control and production improvement study

Energy Technology Data Exchange (ETDEWEB)

Hostick, C. J.; Imhoff, C. H.; Levine, L. O.

1986-04-01

The purpose of this report is to assist the Hanford regulated laundry facility in reducing processing costs and in improving facility performance. Specific problem areas addressed were: no method for determining optimum manpower requirements, resulting in excessive amounts of employee overtime; no buffer inventory available to offset demand peaks, resulting in additional employee overtime and unmet demand; lack of adequate inventory control, resulting in unnecessary inventory costs; and no detailed analysis of the impact of 100% monitoring.

A GRASP METAHEURISTIC FOR THE ORDERED CUTTING STOCK PROBLEM UN META-HEURÍSTICO GRASP PARA EL PROBLEMA DE STOCK DE CORTE ORDENADO

Directory of Open Access Journals (Sweden)

Rodrigo Rabello Golfeto

2008-12-01

Full Text Available This study presents a new mathematical model and a Greedy Randomized Adaptive Search Procedure (GRASP meta-heuristic to solve the ordered cutting stock problem. The ordered cutting stock problem was recently introduced in literature. It is appropriate to minimize the raw material used by industries that deal with reduced product inventories, such as industries that use the just-in-time basis for their production. In such cases, classic models for solving the cutting stock problem are useless. Results obtained from computational experiments for a set of random instances demonstrate that the proposed method can be applied to large industries that process cuts on their production lines and do not stock their products.Este estudio presenta un nuevo modelo matemático y un procedimiento meta-heurístico de búsqueda voraz adaptativa y aleatoria (GRASP, por sus siglas en inglés para resolver el problema de stock de corte ordenado. Éste problema ha sido introducido recientemente en la literatura. Es apropiado minimizar la materia prima usada por las industrias que manipulan inventarios reducidos de productos, tales como las industrias que usan la base justo a tiempo para su producción. En tales casos, los modelos clásicos para resolver el problema de stock de corte ordenado son inútiles. Los resultados obtenidos, mediante experimentos computacionales para un conjunto de ejemplos aleatorios, demuestran que el método propuesto puede ser aplicado a industrias grandes que procesan cortes en sus líneas de producción y no mantienen en stock sus productos.

Potential gains in storage on productive forestlands in the northeastern United Sates through stocking management

Science.gov (United States)

Coeli Hoover; Linda S. Heath

2011-01-01

One method of increasing forest carbon stocks that is often discussed is increasing stocking levels on existing forested lands. However, estimates of the potential increases in forest carbon sequestration as a result of increased stocking levels are not readily available. Using the USDA Forest Service's Forest Inventory and Analysis data coupled with the Forest...

Automated Interactive Storeroom Inventory System.

Science.gov (United States)

Sapp, Albert L.; Hess, Larry G.

1989-01-01

The inventory system designed for six storerooms in three buildings at the University of Illinois at Urbana-Champaign's School of Chemical Sciences replaced an issue-slip and transactions record system with barcode technology. Data collection error reductions have been significant, making it easier to determine stock levels and plan purchases.…

Range-based volatility, expected stock returns, and the low volatility anomaly

Science.gov (United States)

2017-01-01

One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics. PMID:29190652

Range-based volatility, expected stock returns, and the low volatility anomaly.

Science.gov (United States)

Blau, Benjamin M; Whitby, Ryan J

2017-01-01

One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics.

Range-based volatility, expected stock returns, and the low volatility anomaly.

Directory of Open Access Journals (Sweden)

Benjamin M Blau

Full Text Available One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility, which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics.

Components of Inventory Change (CINCH) reports 2007-2009

Data.gov (United States)

Department of Housing and Urban Development — The Components of Inventory Change (CINCH) report measures changes in the characteristics of the housing stock of the United States. Using data collected from the...

Potential increases in natural disturbance rates could offset forest management impacts on ecosystem carbon stocks

Science.gov (United States)

Bradford, John B.; Jensen, Nicholas R.; Domke, Grant M.; D’Amato, Anthony W.

2013-01-01

Forested ecosystems contain the majority of the world’s terrestrial carbon, and forest management has implications for regional and global carbon cycling. Carbon stored in forests changes with stand age and is affected by natural disturbance and timber harvesting. We examined how harvesting and disturbance interact to influence forest carbon stocks over the Superior National Forest, in northern Minnesota. Forest inventory data from the USDA Forest Service, Forest Inventory and Analysis program were used to characterize current forest age structure and quantify the relationship between age and carbon stocks for eight forest types. Using these findings, we simulated the impact of alternative management scenarios and natural disturbance rates on forest-wide terrestrial carbon stocks over a 100-year horizon. Under low natural mortality, forest-wide total ecosystem carbon stocks increased when 0% or 40% of planned harvests were implemented; however, the majority of forest-wide carbon stocks decreased with greater harvest levels and elevated disturbance rates. Our results suggest that natural disturbance has the potential to exert stronger influence on forest carbon stocks than timber harvesting activities and that maintaining carbon stocks over the long-term may prove difficult if disturbance frequency increases in response to climate change.

Cost optimization in the (S-1,S) lost sales inventory model with multiple demand classes

NARCIS (Netherlands)

Kranenburg, A.A.; Houtum, van G.J.J.A.N.

2007-01-01

For the (S-1,S) lost sales inventory model with multiple demand classes that have different lost sales penalty cost parameters, three accurate and efficient heuristic algorithms are presented that, at a given base stock level, aim to find optimal values for the critical levels, i.e., values that

Trestima – Digital Photographs for Forest Inventory

Directory of Open Access Journals (Sweden)

T. Rouvinen

2014-10-01

Full Text Available Higher efficiency of forest survey is a corner stone of forest inventory and forest planning. Mobile technologies create a unique opportunity to solve the problem as well as measurement accuracy improvement, higher data objectiveness and independent control of the results. Trestima technology bases on extraction of forest attributes such as basal area, tree stem diameter, tree height and species distribution from photographs captured by a mobile phone. Image processing is performed automatically in a cloud service using machine vision, which is aided by a human operator when necessary. That allows automating all further calculations. Functions of electronic compass and geopositioning implemented on modern smart-phones allows registering the direction as well as sufficiently accurate geographic coordinates, which enables unambiguously association of a measurement and its location. The service produces reports about timber stock, basal area, average diameter, average height, number of tree trunks and diameter distribution. The report prepared for each tree stand includes standard error, as well as confidence interval for the measurements results and the assessment, with a 95 % probability level. Using thecross-section area, the average diameter and average height, the timber stock and the number of stems in the specific area may be calculated. The report generated by Trestima can be easily supplemented by a derived parameters, as well as any of the applicable formulas can be easily modified or altered in accordance with the needs, for example, dependingon the particularforest inventory area. One of the key features of the Trestima technology is the fact that each measurement contains geographic coordinates’ data. It means that, the location of eachmeasurementcan be displayedon the map, and the route, and the area cover under consideration can be analyzed.

Radioactive material inventory control at a waste characterization facility

International Nuclear Information System (INIS)

Yong, L.K.; Chapman, J.A.; Schultz, F.J.

1996-01-01

Due to the recent introduction of more stringent Department of Energy (DOE) regulations and requirements pertaining to nuclear and criticality safety, the control of radioactive material inventory has emerged as an important facet of operations at DOE nuclear facilities. In order to comply with nuclear safety regulations and nuclear criticality requirements, radioactive material inventories at each nuclear facility have to be maintained below limits specified for the facility in its safety authorization basis documentation. Exceeding these radioactive material limits constitutes a breach of the facility's nuclear and criticality safety envelope and could potentially result in an accident, cause a shut-down of the facility, and bring about imminent regulatory repercussions. The practice of maintaining control of radioactive material, especially sealed and unsealed sources, is commonplace and widely implemented; however, the requirement to track the entire radioactivity inventory at each nuclear facility for the purpose of ensuring nuclear safety is a new development. To meet the new requirements, the Applied Radiation Measurements Department at Oak Ridge National Laboratory (ORNL) has developed an information system, called the open-quotes Radioactive Material Inventory Systemclose quotes (RMIS), to track the radioactive material inventory at an ORNL facility, the Waste Examination and Assay Facility (WEAF). The operations at WEAF, which revolve around the nondestructive assay and nondestructive examination of waste and related research and development activities, results in an ever-changing radioactive material inventory. Waste packages and radioactive sources are constantly being brought in or taken out of the facility; hence, use of the RMIS is necessary to ensure that the radioactive material inventory limits are not exceeded

Integrated data base for spent fuel and radwaste: inventories

International Nuclear Information System (INIS)

Notz, K.J.; Carter, W.L.; Kibbey, A.H.

1982-01-01

The Integrated Data Base (IDB) program provides and maintains current, integrated data on spent reactor fuel and radwaste, including historical data, current inventories, projected inventories, and material characteristics. The IDB program collects, organizes, integrates, and - where necessary - reconciles inventory and projection (I/P) and characteristics information to provide a coherent, self-consistent data base on spent fuel and radwaste

Cash management improvement in the Navy Stock Fund

OpenAIRE

Linquist, James E.; Evans, Timothy S.

1986-01-01

Approved for public release; distribution is unlimited The Navy Stock Fund (NSF) is a working capital fund used to purchase and hold designated inventories of supply items at various stock points until needed by a customer. The fund is currently comprised of ten separate Budget Projects with total collections and expenditures projected to be in excess of $ 1 8 bi 1 1 ion for Fiscal Year 1 986. The authors examined the background and current operation of the NSF with empha...

30 CFR 764.21 - Data base and inventory system requirements.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Data base and inventory system requirements... SURFACE COAL MINING OPERATIONS § 764.21 Data base and inventory system requirements. (a) The regulatory authority shall develop a data base and inventory system which will permit evaluation of whether reclamation...

Carbon stores, sinks, and sources in forests of northwestern Russia: can we reconcile forest inventories with remote sensing results?

Science.gov (United States)

Olga N. Krankina; Mark E. Harmon; Warren B. Cohen; Doug R. Oetter; Olga Zyrina; Maureen V. Duane

2004-01-01

Forest inventories and remote sensing are the two principal data sources used to estimate carbon (C) stocks and fluxes for large forest regions. National governments have historically relied on forest inventories for assessments but developments in remote sensing technology provide additional opportunities for operational C monitoring. The estimate of total C stock in...

Using the Expert Systems for Determining the Products Stored and the Products Taken Out of the Inventory

Directory of Open Access Journals (Sweden)

Veronica Grosu

2007-01-01

Full Text Available The analysis of the products stored and theproducts taken out of the inventory represents one of the basicproblems of an economy in crisis. Not controlling thesephenomena as regards the entire economy can lead to blockingthe economic circuits and even to a financial blockage.Obtaining semi-finished products, finished products andresidual products generates a potential income for the economicunit included in the accountancy analysis through the account711 “Stocks variations” that has the role of an intermediaryincomes account considering the stage of the economic circuitsduring which the incomes assessments on are made. Thebalance of the account 711 “Stocks variation” is shown in theprofit and loss statement, at the corresponding column in theoperating revenues structure in order to calculate the “financialyear production”.Closing the financial year represents one of the mostimportant moments of the activities that are performed by thefinancial-accountancy department. This is the basic reason fordeveloping some expert systems that would assist the analysiswork of the patrimonial statement and the obtaining ofinformation as regards the policy of the economic unitconcerning the level of products inventory resulting from theoperating activity. DESTOC is a prototype of the expert systemthat solves aspects related to the finished products, semifinishedand residual products. For the DESTOC prototype it isused the ESIEWIH generator specialized in building scenariosbasedknowledge bases. The DESTOC prototype has as purposedetermining the products stored and the products taken out ofthe inventory and it assumes a series of comments necessary tothe calculus manner.

A periodic review integrated inventory model with controllable setup cost, imperfect items, and inspection errors under service level constraint

Science.gov (United States)

Saga, R. S.; Jauhari, W. A.; Laksono, P. W.

2017-11-01

This paper presents an integrated inventory model which consists of single vendor and buyer. The buyer managed its inventory periodically and orders products from the vendor to satisfy the end customer’s demand, where the annual demand and the ordering cost were in the fuzzy environment. The buyer used a service level constraint instead of the stock-out cost term, so that the stock-out level per cycle was bounded. Then, the vendor produced and delivered products to the buyer. The vendor had a choice to commit an investment to reduce the setup cost. However, the vendor’s production process was imperfect, thus the lot delivered contained some defective products. Moreover, the buyer’s inspection process was not error-free since the inspector could be mistaken in categorizing the product’s quality. The objective was to find the optimum value for the review period, the setup cost, and the number of deliveries in one production cycle which might minimize the joint total cost. Furthermore, the algorithm and numerical example were provided to illustrate the application of the model.

A time-based control policy for a perishable inventory system with lost sales

OpenAIRE

Tekin, Eylem

1998-01-01

Ankara : Department of Industrial Engineering and the Institute of Engineering and Science of Bilkent Univ., 1998. Thesis (Master's) -- Bilkent University, 1998. Includes bibliographical references leaves 49-52 In this study, we propose a new time-based poiicy for continuous review inventory systems where the products have fixed fife times and unmet denicinds are iost. We cierive the exact expressions of the key operating characteristics of the rnociei. Based on these perfo...

Concepts for reducing nuclear utility inventory carrying costs

International Nuclear Information System (INIS)

Graybill, R.E.; DiCola, F.E.; Solanas, C.H.

1985-01-01

Nuclear utilities are under pressure to reduce their operating and maintenance expenses such that the total cost of generating electricity through nuclear power remains an economically attractive option. One area in which expenses may be reduced is total inventory carrying cost. The total inventory carrying cost consists of financing an inventory, managing the inventory, assuring quality, engineering of acceptable parts specifications, and procuring initial and replenishment stock. Concepts and methodology must be developed to reduce the remaining expenses of a utility's total inventory carrying cost. Currently, two concepts exist: pooled inventory management system (PIMS), originally established by General Electric Company and a group of boiling water reactor owners, and Nuclear Parts Associates' (NUPA) shared inventory management program (SIMP). Both concepts share or pool parts and components among utilities. The SIMP program objectives and technical activities are summarized

Price and inventory dynamics in petroleum product markets

International Nuclear Information System (INIS)

Considine, T.J.; Heo, Eunnyeong

2000-01-01

Unlike many studies of commodity inventory behavior, this paper estimates a model with endogenous spot and forward prices, inventories, production, and net imports. Our application involves markets for refined petroleum products in the United States. Our model is built around the supply and demand for storage. We estimate the model using Generalized Method of Moments and perform dynamic, simultaneous simulations to estimate the impacts of supply and demand shocks. Supply curves for the industry are inelastic and upward sloping. High inventory levels depress prices. Inventories fall in response to higher sales, consistent with production smoothing. Under higher input prices, refiners reduce their stocks of crude oil but increase their product inventories, consistent with cost smoothing. In some cases, imports of products are more variable than production or inventories. 25 refs

Inventory control in multi-item production systems

NARCIS (Netherlands)

Bruin, J.

2010-01-01

This thesis focusses on the analysis and construction of control policies in multiitem production systems. In such systems, multiple items can be made to stock, but they have to share the finite capacity of a single machine. This machine can only produce one unit at a time and if it is set-up for

Inventory Model for Non – Instantaneous Deteriorating Items, Stock Dependent Demand, Partial Backlogging, and Inflation over a Finite Time Horizon

Directory of Open Access Journals (Sweden)

Neeraj Kumar

2016-05-01

Full Text Available In the present study, the Economic Order Quantity (EOQ model of two-warehouse deals with non-instantaneous deteriorating items, the demand rate considered as stock dependent and model affected by inflation under the pattern of time value of money over a finite planning horizon. Shortages are allowed and partially backordered depending on the waiting time for the next replenishment. The main objective of this work is to minimize the total inventory cost and finding the optimal interval and the optimal order quantity. An algorithm is designed to find the optimum solution of the proposed model. Numerical examples are given to demonstrate the results. Also, the effect of changes in the different parameters on the optimal total cost is graphically presented.

A Modular Integrated RFID System for Inventory Control Applications

Directory of Open Access Journals (Sweden)

Ross Bunker

2017-01-01

Full Text Available Recent advances in single-board computer technology have allowed for lightweight, power-efficient devices, such as the Raspberry Pi, to take the place of desktop PCs in certain applications. This has the potential to disrupt the way many current systems are structured, particularly for inventory management and control applications. In this paper, we explore the design and topology of a modular Radio frequency identification (RFID system for inventory management comprised of self-contained, autonomous scanning, and stationary control PCs in a handheld/portable configuration. While similar solutions for such a system may exist on the commercial market, this proposed development provides a template for an open source flexible, low-cost solution that can be easily expanded to meet the needs of businesses with large and small inventories.

Accounting for density reduction and structural loss in standing dead trees: Implications for forest biomass and carbon stock estimates in the United States

Directory of Open Access Journals (Sweden)

Domke Grant M

2011-11-01

Full Text Available Abstract Background Standing dead trees are one component of forest ecosystem dead wood carbon (C pools, whose national stock is estimated by the U.S. as required by the United Nations Framework Convention on Climate Change. Historically, standing dead tree C has been estimated as a function of live tree growing stock volume in the U.S.'s National Greenhouse Gas Inventory. Initiated in 1998, the USDA Forest Service's Forest Inventory and Analysis program (responsible for compiling the Nation's forest C estimates began consistent nationwide sampling of standing dead trees, which may now supplant previous purely model-based approaches to standing dead biomass and C stock estimation. A substantial hurdle to estimating standing dead tree biomass and C attributes is that traditional estimation procedures are based on merchantability paradigms that may not reflect density reductions or structural loss due to decomposition common in standing dead trees. The goal of this study was to incorporate standing dead tree adjustments into the current estimation procedures and assess how biomass and C stocks change at multiple spatial scales. Results Accounting for decay and structural loss in standing dead trees significantly decreased tree- and plot-level C stock estimates (and subsequent C stocks by decay class and tree component. At a regional scale, incorporating adjustment factors decreased standing dead quaking aspen biomass estimates by almost 50 percent in the Lake States and Douglas-fir estimates by more than 36 percent in the Pacific Northwest. Conclusions Substantial overestimates of standing dead tree biomass and C stocks occur when one does not account for density reductions or structural loss. Forest inventory estimation procedures that are descended from merchantability standards may need to be revised toward a more holistic approach to determining standing dead tree biomass and C attributes (i.e., attributes of tree biomass outside of sawlog

Site productivity and forest carbon stocks in the United States: Analysis and implications for forest offset project planning

Science.gov (United States)

Coeli M. Hoover; James E. Smith

2012-01-01

The documented role of United States forests in sequestering carbon, the relatively low cost of forest-based mitigation, and the many co-benefits of increasing forest carbon stocks all contribute to the ongoing trend in the establishment of forest-based carbon offset projects. We present a broad analysis of forest inventory data using site quality indicators to provide...

Rapid diagnostic test supply chain and consumption study in Cabo Delgado, Mozambique: estimating stock shortages and identifying drivers of stock-outs.

Science.gov (United States)

Hasselback, Leah; Crawford, Jessica; Chaluco, Timoteo; Rajagopal, Sharanya; Prosser, Wendy; Watson, Noel

2014-08-02

Malaria rapid diagnostic tests (RDTs) are particularly useful in low-resource settings where follow-through on traditional laboratory diagnosis is challenging or lacking. The availability of these tests depends on supply chain processes within the distribution system. In Mozambique, stock-outs of malaria RDTs are fairly common at health facilities. A longitudinal cross-sectional study was conducted to evaluate drivers of stock shortages in the Cabo Delgado province. Data were collected from purposively sampled health facilities, using monthly cross-sectional surveys between October 2011 and May 2012. Estimates of lost consumption (consumption not met due to stock-outs) served as the primary quantitative indicator of stock shortages. This is a better measure of the magnitude of stock-outs than binary indicators that only measure frequency of stock-outs at a given facility. Using a case study based methodology, distribution system characteristics were qualitatively analysed to examine causes of stock-outs at the provincial, district and health centre levels. 15 health facilities were surveyed over 120 time points. Stock-out patterns varied by data source; average monthly proportions of 59%, 17% and 17% of health centres reported a stock-out on stock cards, laboratory and pharmacy forms, respectively. Estimates of lost consumption percentage were significantly high; ranging from 0% to 149%; with a weighted average of 78%. Each ten-unit increase in monthly-observed consumption was associated with a nine-unit increase in lost consumption percentage indicating that higher rates of stock-outs occurred at higher levels of observed consumption. Causes of stock-outs included inaccurate tracking of lost consumption, insufficient sophistication in inventory management and replenishment, and poor process compliance by facility workers, all arguably stemming from inadequate attention to the design and implementation of the distribution system. Substantially high levels of RDT

On jointly optimising the changes of seasonable goods and inventory replenishment

Science.gov (United States)

Li, Zhaolin; Tao, Feng; Sun, Daewon

2012-06-01

Retailers often need to replace soon-to-be-unseasonable products with new seasonable goods when the season changes. The trade-off for such activities involves choosing between the salvage loss of the unseasonable product and the profit of selling the seasonable product early. This article develops a periodic-review inventory model for planning the changes of seasonable goods with state-dependent demand and cost parameters. We show that the single-period optimal policy for product changes is a threshold policy based on the initial inventory of the unseasonable goods. The corresponding optimal inventory policy follows a Purchase-Keep-Dispose policy if the incumbent product is kept or a base-stock policy if the incumbent product is replaced. Numerically, we find that the structure of the multi-period optimal policy resembles that of the single-period model. We propose a heuristic to solve the multi-period model and demonstrate its effectiveness. Our research provides insights into dynamically managing seasonable goods.

Optimization of Inventory

OpenAIRE

PROKOPOVÁ, Nikola

2017-01-01

The subject of this thesis is optimization of inventory in selected organization. Inventory optimization is a very important topic in each organization because it reduces storage costs. At the beginning the inventory theory is presented. It shows the meaning and types of inventory, inventory control and also different methods and models of inventory control. Inventory optimization in the enterprise can be reached by using models of inventory control. In the second part the company on which is...

Automated Stock Control System for Bookshops in Tertiary Institutions

African Journals Online (AJOL)

PROF. O. E. OSUAGWU

2013-09-01

Sep 1, 2013 ... 2Department of Computer Science, Nnamdi Azikiwe University, ... database systems in developing stock control systems for ... information is generally accessible from various terminals ... A distributed database can normally be applied by business units, ... instances of a database management system.

Carbon stocks in tree biomass and soils of German forests

Directory of Open Access Journals (Sweden)

Wellbrock Nicole

2017-06-01

Full Text Available Close to one third of Germany is forested. Forests are able to store significant quantities of carbon (C in the biomass and in the soil. Coordinated by the Thünen Institute, the German National Forest Inventory (NFI and the National Forest Soil Inventory (NFSI have generated data to estimate the carbon storage capacity of forests. The second NFI started in 2002 and had been repeated in 2012. The reporting time for the NFSI was 1990 to 2006. Living forest biomass, deadwood, litter and soils up to a depth of 90 cm have stored 2500 t of carbon within the reporting time. Over all 224 t C ha-1 in aboveground and belowground biomass, deadwood and soil are stored in forests. Specifically, 46% stored in above-ground and below-ground biomass, 1% in dead wood and 53% in the organic layer together with soil up to 90 cm. Carbon stocks in mineral soils up to 30 cm mineral soil increase about 0.4 t C ha-1 yr-1 stocks between the inventories while the carbon pool in the organic layers declined slightly. In the living biomass carbon stocks increased about 1.0 t C ha-1 yr-1. In Germany, approximately 58 mill. tonnes of CO2 were sequestered in 2012 (NIR 2017.

Connecting inventory control and repair shop control : a differentiated control structure for repairable spare parts

NARCIS (Netherlands)

Driessen, M.A.; Rustenburg, W.D.; Houtum, van G.J.J.A.N.; Wiers, V.C.S.

2014-01-01

This paper presents a control structure for integrating decisions on spare parts inventory control and the control of repair shops for maintenance spare parts. A dierentiated control structure is proposed for the various repair shop types recognized in practice. Decisions functions are mapped and

Biomasse et stocks de carbone des forêts tropicales africaines (synthèse bibliographique

Directory of Open Access Journals (Sweden)

Loubota Panzou, GJ.

2016-01-01

Full Text Available Biomass and carbon stocks of tropical African forests. A review. Introduction. Quantifying the biomass and carbon stocks contained in tropical forests has become an international priority for the implementation of the REDD+ mechanism. Forest biomass is estimated at three successive levels: the tree, the stand and the region level. This paper reviews the state of the art regarding the estimation of biomass and carbon stocks in tropical African forests. Literature. This review highlights the fact that very few allometric equations, equations used for estimating the biomass of the tree using non-destructive measurements (diameter, height, have been established for tropical African forests. At the stand level, the review highlights the spatial and temporal variations in biomass between forest types in Central and Eastern Africa. While biomass recovery after a disturbance (logging, for instance is rather quick, a great deal of uncertainty still remains regarding the spatial variation in biomass, and there is no consensus on a regional biomass map. The quality of biomass mapping in tropical Africa strongly depends on the type of remotely-sensed data being used (optical, RADAR or LIDAR, and the allometric equation used to convert forest inventory data into biomass. Conclusions. Based on the lack of precision of the available allometric equations and forest inventory data and the large spatial scale involved, many uncertainties persist in relation to the estimation of the biomass and carbon stocks contained in African tropical forests.

The economics of controlling stock pollutants: An efficient strategy for greenhouse gases

International Nuclear Information System (INIS)

Falk, I.; Mendelsohn, R.

1993-01-01

Optimal control theory is applied to develop an efficient strategy to control stock pollutants such as greenhouse gases and hazardous waste. The optimal strategy suggests that, at any time, the marginal costs of abatement should be equated with the present value of the marginal damage of timely unabated emission. The optimal strategy calls for increasingly tight abatement over time as the pollutant stock accumulates. The optimal policy applied to greenhouse gases suggest moderate abatement efforts, at present, with the potential for much greater future efforts. 15 refs., 2 tabs

Wisconsin's fourth forest inventory, 1983.

Science.gov (United States)

John S. Jr. Spencer; W. Brad Smith; Jerold T. Hahn; Gerhard K. Raile

1988-01-01

The fourth inventory of the timber resource of Wisconsin shows that growing-stock volume increased from 11.2 to 15.5 billion cubic feet between 1968 and 1983, and area of timberland increased from 14.5 to 14.8 million acres. Presented are analysis and statistics on forest area and timber volume, growth, mortality, removals, and projections.

Cost Analysis for a Supplier in an Inflationary Environment with Stock Dependent Demand Rate for Perishable Items

Directory of Open Access Journals (Sweden)

Madhu Jain

2014-01-01

Full Text Available The present study is concerned with the cost modeling of an inventory system with perishable multi-items having stock dependent demand rates under an inflationary environment of the market. The concept of permissible delay is taken into account. The study provides the cost analysis of inventory system under the decision criteria of time value of money, inflation, deterioration, and stock dependent demand. Numerical illustrations are derived from the quantitative model to validate the results. The cost of inventory and optimal time are also computed by varying different system parameters. The comparison of these results is facilitated by computing the results with neurofuzzy results.

Controlling Inventory: Real-World Mathematical Modeling

Science.gov (United States)

Edwards, Thomas G.; Özgün-Koca, S. Asli; Chelst, Kenneth R.

2013-01-01

Amazon, Walmart, and other large-scale retailers owe their success partly to efficient inventory management. For such firms, holding too little inventory risks losing sales, whereas holding idle inventory wastes money. Therefore profits hinge on the inventory level chosen. In this activity, students investigate a simplified inventory-control…

Estimating dead wood during national forest inventories: a review of inventory methodologies and suggestions for harmonization

Science.gov (United States)

Christopher W. Woodall; Jacques Rondeux; Pieter J. Verkerk; G& #246; ran St& #229; hl

2009-01-01

Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world's forested landscapes is scattered. The goal of this study...

Forecast Correlation Coefficient Matrix of Stock Returns in Portfolio Analysis

OpenAIRE

Zhao, Feng

2013-01-01

In Modern Portfolio Theory, the correlation coefficients decide the risk of a set of stocks in the portfolio. So, to understand the correlation coefficients between returns of stocks, is a challenge but is very important for the portfolio management. Usually, the stocks with small correlation coefficients or even negative correlation coefficients are preferred. One can calculate the correlation coefficients of stock returns based on the historical stock data. However, in order to control the ...

Based on BP Neural Network Stock Prediction

Science.gov (United States)

Liu, Xiangwei; Ma, Xin

2012-01-01

The stock market has a high profit and high risk features, on the stock market analysis and prediction research has been paid attention to by people. Stock price trend is a complex nonlinear function, so the price has certain predictability. This article mainly with improved BP neural network (BPNN) to set up the stock market prediction model, and…

A remote sensing-based model of tidal marsh aboveground carbon stocks for the conterminous United States

Science.gov (United States)

Byrd, Kristin B.; Ballanti, Laurel; Thomas, Nathan; Nguyen, Dung; Holmquist, James R.; Simard, Marc; Windham-Myers, Lisamarie

2018-05-01

Remote sensing based maps of tidal marshes, both of their extents and carbon stocks, have the potential to play a key role in conducting greenhouse gas inventories and implementing climate mitigation policies. Our objective was to generate a single remote sensing model of tidal marsh aboveground biomass and carbon that represents nationally diverse tidal marshes within the conterminous United States (CONUS). We developed the first calibration-grade, national-scale dataset of aboveground tidal marsh biomass, species composition, and aboveground plant carbon content (%C) from six CONUS regions: Cape Cod, MA, Chesapeake Bay, MD, Everglades, FL, Mississippi Delta, LA, San Francisco Bay, CA, and Puget Sound, WA. Using the random forest machine learning algorithm, we tested whether imagery from multiple sensors, Sentinel-1 C-band synthetic aperture radar, Landsat, and the National Agriculture Imagery Program (NAIP), can improve model performance. The final model, driven by six Landsat vegetation indices and with the soil adjusted vegetation index as the most important (n = 409, RMSE = 310 g/m2, 10.3% normalized RMSE), successfully predicted biomass for a range of marsh plant functional types defined by height, leaf angle and growth form. Model results were improved by scaling field-measured biomass calibration data by NAIP-derived 30 m fraction green vegetation. With a mean plant carbon content of 44.1% (n = 1384, 95% C.I. = 43.99%-44.37%), we generated regional 30 m aboveground carbon density maps for estuarine and palustrine emergent tidal marshes as indicated by a modified NOAA Coastal Change Analysis Program map. We applied a multivariate delta method to calculate uncertainties in regional carbon densities and stocks that considered standard error in map area, mean biomass and mean %C. Louisiana palustrine emergent marshes had the highest C density (2.67 ± 0.004 Mg/ha) of all regions, while San Francisco Bay brackish/saline marshes had the highest C density of all

Brownian motion approximations for stock control and tankage assessment

NARCIS (Netherlands)

R.A.J.J. Nieboer; R. Dekker (Rommert)

1995-01-01

textabstractThis paper presents a model for refinery tankage assessment. Special characteristics covered are a hybrid demand process and a periodic-review target-stock policy for production control. The demand is assumed to be in two forms: as large parcels, collected at fixed intervals, and as many

41 CFR 101-27.406 - Disposition of stock.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Disposition of stock. 101-27.406 Section 101-27.406 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 27-INVENTORY MANAGEMENT 27.4...

Research on energy stock market associated network structure based on financial indicators

Science.gov (United States)

Xi, Xian; An, Haizhong

2018-01-01

A financial market is a complex system consisting of many interacting units. In general, due to the various types of information exchange within the industry, there is a relationship between the stocks that can reveal their clear structural characteristics. Complex network methods are powerful tools for studying the internal structure and function of the stock market, which allows us to better understand the stock market. Applying complex network methodology, a stock associated network model based on financial indicators is created. Accordingly, we set threshold value and use modularity to detect the community network, and we analyze the network structure and community cluster characteristics of different threshold situations. The study finds that the threshold value of 0.7 is the abrupt change point of the network. At the same time, as the threshold value increases, the independence of the community strengthens. This study provides a method of researching stock market based on the financial indicators, exploring the structural similarity of financial indicators of stocks. Also, it provides guidance for investment and corporate financial management.

DEA-BASED INVESTMENT STRATEGY AND ITS APPLICATION IN THE CROATIAN STOCK MARKET

Directory of Open Access Journals (Sweden)

Margareta Gardijan

2012-12-01

Full Text Available This paper describes the DEA-based investment strategy for constructing of a stock portfolio in the Croatian stock market. The relative efficiency of the DMUs, which are in this case the selected stocks from Zagreb Stock Exchange, is obtained from the output oriented CCR and BCC models. The set of inputs consists of risk measures, namely return variance, Value at Risk (VaR and beta coefficient $(\\beta$, while monthly return represents an output. Following the „efficiency scores“, obtained from the models, we construct a portfolio of DEA-efficient stocks (DEA-portfolio. This portfolio can be modified over time according to changes of the DMU's efficiency scores. By comparing the returns of the EA-portfolio and the market return during the given time period, the applicability of the investment strategy based on a DEA methodology, as a strategy for achieving superior returns, is estimated.

Optimizing Safety Stock Levels in Modular Production Systems Using Component Commonality and Group Technology Philosophy: A Study Based on Simulation

Directory of Open Access Journals (Sweden)

Kenneth Edgar Hernandez-Ruiz

2016-01-01

Full Text Available Modular production and component commonality are two widely used strategies in the manufacturing industry to meet customers growing needs for customized products. Using these strategies, companies can enhance their performance to achieve optimal safety stock levels. Despite the importance of safety stocks in business competition, little attention has been paid to the way to reduce them without affecting the customer service levels. This paper develops a mathematical model to reduce safety stock levels in organizations that employ modular production. To construct the model, we take advantage of the benefits of aggregate inventories, standardization of components, component commonality, and Group Technology philosophy in regard to stock levels. The model is tested through the simulation of three years of operation of two modular product systems. For each system, we calculated and compared the safety stock levels for two cases: (1 under the only presence of component commonality and (2 under the presence of both component commonality and Group Technology philosophy. The results show a reduction in safety stock levels when we linked the component commonality with the Group Technology philosophy. The paper presents a discussion of the implications of each case, features of the model, and suggestions for future research.

Sistem Optimasi Inventory Berbasis Layanan Web Di PT Pelita Biru

Directory of Open Access Journals (Sweden)

Cristeddy Asa Bakti

2017-05-01

Full Text Available Various types of LPG sold, requiring a precise inventory management, especially the facts on the ground are often encountered uncertainties include uncertainty of demand and the performance cycle. The aim of this research  is to develop  decision making system to optimize inventory by the Economic Order Quantity method based on the Bowersox formula by using the combining of variables for demand uncertainty and performance cycle. The system uses the web service media method for easy access and maintenance with centralized data on the server and users only use the existing browser. The method of categorizing goods uses the category ABC by dividing the type of goods into categories A (very important, B (important and C (not important. The results provide safe inventory value calculations based on variables of  uncertainty and performance cycles. With the optimization resulting from this system, the company can maintain the availability of the goods by making appropriate arrangements, priorities, and the amount so as to minimize the occurrence of the possibility of excess and lack of stock.

DEA-BASED INVESTMENT STRATEGY AND ITS APPLICATION IN THE CROATIAN STOCK MARKET

OpenAIRE

Margareta Gardijan; Vedran Kojić

2012-01-01

This paper describes the DEA-based investment strategy for constructing of a stock portfolio in the Croatian stock market. The relative efficiency of the DMUs, which are in this case the selected stocks from Zagreb Stock Exchange, is obtained from the output oriented CCR and BCC models. The set of inputs consists of risk measures, namely return variance, Value at Risk (VaR) and beta coefficient $(\\beta)$, while monthly return represents an output. Following the „efficiency scores“, obtained f...

Improvement of Inventory Control Using Continuous Review Policy in A Local Hospital at Bandung City, Indonesia

Directory of Open Access Journals (Sweden)

Fina Hafnika

2016-12-01

Full Text Available Abstract. This research was aimed to analyze the excess inventories issue in pharmacy and medical equipment unit at a local hospital in Bandung which affected the service level of the hospital. As one of the busy hospital in Java, proven by the higher amount of the patient/year than in other average Java typical hospital, the hospital needs to concern about the pharmaceutical and medical equipment inventories in order to fulfill patients’ needs and in the same time keeping the inventory level under control. Therefore, an inventory control evaluation was conducted to determine the appropriate number of inventories and time of order to avoid the excessive goods in central warehouse of the hospital. By using probabilistic inventory model and continuous review policy, the pharmaceutical inventory in the hospital was calculated to compare the ideal and actual amount of the average inventory level (AIL. ABC (Always, Better, Control classification also classified in this research to identify the proper item which potentially can be reduced from the inventory. From the analysis, we have discovered that the hospital potentially able to reduce almost Rp 830 million or 57% from the overstock inventory level by using continuous review policy as the basis of inventory control calculation system. Keywords: Continuous review policy, inventory control, EOQ, ROP, AIL

Investment Strategy on the Zagreb Stock Exchange Based on Dynamic DEA

Directory of Open Access Journals (Sweden)

Tihana Škrinjarić

2014-04-01

Full Text Available Nowadays, there is a growing interest in the application of quantitative methods in portfolio management, as the results of their application can be used as guidelines for managing a successful investment portfolio, i.e., a portfolio that outperforms the market. This paper deals with the Data Envelopment Analysis (DEA approach and a Dynamic Slacks-Based Measure as a method of forming a portfolio which would predominantly outperform the market. In order to test the strategy, data on stocks listed on the Zagreb Stock Exchange were gathered for the period April 2009 – June 2012. Using the quarterly returns, standard deviations and coefficients of skewness as links, a dynamic slacks-based measure approach was applied to evaluate the relative efficiency of stocks in each quarter. The findings indicate that a portfolio based on the results of the optimization beats the market in terms of both returns and risk. This is the first implementation of the dynamic DEA model in stock trading. The results suggest that it is superior to basic DEA models.

Geography of Global Forest Carbon Stocks & Dynamics

Science.gov (United States)

Saatchi, S. S.; Yu, Y.; Xu, L.; Yang, Y.; Fore, A.; Ganguly, S.; Nemani, R. R.; Zhang, G.; Lefsky, M. A.; Sun, G.; Woodall, C. W.; Naesset, E.; Seibt, U. H.

2014-12-01

Spatially explicit distribution of carbon stocks and dynamics in global forests can greatly reduce the uncertainty in the terrestrial portion of the global carbon cycle by improving estimates of emissions and uptakes from land use activities, and help with green house gas inventory at regional and national scales. Here, we produce the first global distribution of carbon stocks in living woody biomass at ~ 100 m (1-ha) resolution for circa 2005 from a combination of satellite observations and ground inventory data. The total carbon stored in live woody biomass is estimated to be 337 PgC with 258 PgC in aboveground and 79 PgC in roots, and partitioned globally in boreal (20%), tropical evergreen (50%), temperate (12%), and woodland savanna and shrublands (15%). We use a combination of satellite observations of tree height, remote sensing data on deforestation and degradation to quantify the dynamics of these forests at the biome level globally and provide geographical distribution of carbon storage dynamics in terms sinks and sources globally.

The great carbon push-pull: where science is pushing and policy is pulling the official forest carbon inventory of the US

Science.gov (United States)

C.W. Woodall; G.M. Domke; J. Coulston; M.B. Russell; J.A. Smith; C.H. Perry; S. Healey; A. Gray

2015-01-01

A national system of field inventory plots (FIA) is the primary data source for the annual assessment of US forest carbon (C) stocks and stock-change to meet reporting requirements under the United Nations Framework Convention on Climate Change (UNFCCC). The inventory data and their role in national carbon reporting continue to evolve. The framework of the previous C...

ASPECTS OF THE STOCK VALUATION AND ACCOUNTING IN AGRICULTURAL UNITS IN ROMANIA

Directory of Open Access Journals (Sweden)

Mariana BANUTA

2014-11-01

Full Text Available This paper approaches a current and common and topical problem of the business entities operating in agriculture, the stock valuation and accounting problem. Thus, gradually the article starts from the delimitation of the categories of inventories in agriculture, continues with the reasons for the need to valuate them and shows the stock valuation methods in the current accounting and in other specific situations.

Automated Stock Control System for Bookshops in Tertiary Institutions

African Journals Online (AJOL)

The recent need for automated stock control system for bookshops in tertiary institutions was generated by unequal availability of books and stiff scarcity of books in some areas while in ... This approach provides for faster response times for users because the database is local to each business unit within the organization.

Access to forest inventory data: towards transparency in public administration?

Directory of Open Access Journals (Sweden)

Borghetti M

2007-01-01

Full Text Available Transparency in public administration is an important issue in a modern democracy. Thus, we are glad to know the National Forest Service of Italy (Corpo Forestale dello Stato will make soon available on the web the forest inventory data collected in the ongoing National Inventory of Forests and Carbon stocks. We expect all public administrations “storing” important environmental data sets follow this way.

Design of disturbances control model at automotive company

Science.gov (United States)

Marie, I. A.; Sari, D. K.; Astuti, P.; Teorema, M.

2017-12-01

The discussion was conducted at PT. XYZ which produces automotive components and motorcycle products. The company produced X123 type cylinder head which is a motor vehicle forming component. The disturbances in the production system has affected the company performance in achieving the target of Key Performance Indicator (KPI). Currently, the determination of the percentage of safety stock of cylinder head products is not in accordance to the control limits set by the company (60% - 80%), and tends to exceed the control limits that cause increasing the inventory wastage in the company. This study aims to identify the production system disturbances that occurs in the production process of manufacturing components of X123 type cylinder head products and design the control model of disturbance to obtain control action and determine the safety stock policy in accordance with the needs of the company. The design stage has been done based on the Disturbance Control Model which already existing and customized with the company need in controlling the production system disturbances at the company. The design of the disturbances control model consists of sub-model of the risk level of the disturbance, sub-model of action status, sub-model action control of the disturbance, and sub-model of determining the safety stock. The model can assist the automotive company in taking the decision to perform the disturbances control action in production system cylinder head while controlling the percentage of the safety stock.

An empirical assessment of forest floor carbon stock components across the United States

Science.gov (United States)

Christopher W. Woodall; Charles H. Perry; James A. Westfall

2012-01-01

Despite its prevalent reporting in regional/national greenhouse gas inventories (NGHGI), forest floor (FF) carbon (C) stocks (including litter, humus, and fine woody debris [FWD]) have not been empirically measured using a consistent approach across forests of the US. The goal of this study was to use the first national field inventory of litter and humic layer depths...

Analysis of stock investment selection based on CAPM using covariance and genetic algorithm approach

Science.gov (United States)

Sukono; Susanti, D.; Najmia, M.; Lesmana, E.; Napitupulu, H.; Supian, S.; Putra, A. S.

2018-03-01

Investment is one of the economic growth factors of countries, especially in Indonesia. Stocks is a form of investment, which is liquid. In determining the stock investment decisions which need to be considered by investors is to choose stocks that can generate maximum returns with a minimum risk level. Therefore, we need to know how to allocate the capital which may give the optimal benefit. This study discusses the issue of stock investment based on CAPM which is estimated using covariance and Genetic Algorithm approach. It is assumed that the stocks analyzed follow the CAPM model. To do the estimation of beta parameter on CAPM equation is done by two approach, first is to be represented by covariance approach, and second with genetic algorithm optimization. As a numerical illustration, in this paper analyzed ten stocks traded on the capital market in Indonesia. The results of the analysis show that estimation of beta parameters using covariance and genetic algorithm approach, give the same decision, that is, six underpriced stocks with buying decision, and four overpriced stocks with a sales decision. Based on the analysis, it can be concluded that the results can be used as a consideration for investors buying six under-priced stocks, and selling four overpriced stocks.

THE EARNINGS PER SHARE AND INVENTORY TURNOVER RATIOS IN THE GLOBAL FINANCIAL CRISIS: A COMPARATIVE STUDY FOR FOOD AND TEXTILE SECTORS IN ISTANBUL STOCK EXCHANGE

Directory of Open Access Journals (Sweden)

Sudi APAK

2009-01-01

Full Text Available The ongoing financial crisis in the global markets, which originated in the US subprime mortgage segment (real estate and quickly spread into other market segments and countries, is already seen today as one of the biggest financial crises in history. Underlying the subprime crisis had essentially two interrelated factors; the boom in US real estate markets, and the high liquidity demand in the global financial markets. The later period was, in turn, fuelled by the significant easing of US monetary policy over an extended period of time and by the additional boost to global liquidity as many emerging markets had tied their exchange rates to the US dollar and therefore had to match the expansive US monetary policy. The occurrence of market crash or financial crisis is possible key factor of earning per share (EPS and inventory turnover ratios (ITR inefficiency. This paper empirically investigates that the effects of the current financial crisis on the efficiency -earning per share (EPS and inventory turnover ratios- listed food and textile companies in Istanbul Stock Exchange (ISE. The EPS and inventory turnover ratios, applying the multivariate test statistics for the two sub-periods of pre-crisis and the crisis time. The article proceeds in the following manner. Firstly, the study will explain main reasons of global financial crises. Secondly the study will analyze all EPS and inventory turnover ratios changing are of related companies. Finally, that will be argued for adjustment of related ratios of sectors.

Blood inventory management: hospital best practice.

Science.gov (United States)

Stanger, Sebastian H W; Yates, Nicola; Wilding, Richard; Cotton, Sue

2012-04-01

Blood is a perishable product, and hence good management of inventories is crucial. Blood inventory management is a trade-off between shortage and wastage. The challenge is to keep enough stock to ensure a 100% supply of blood while keeping time expiry losses at a minimum. This article focuses on inventory management of red blood cells in hospital transfusion laboratories to derive principles of best practice and makes recommendations that will ensure losses due to time expiry are kept to a minimum. The literature was reviewed to identify available models for perishable inventory management. Historical data from the UK blood supply chain was analyzed to identify hospitals with good inventory management practice and low wastage levels. Transfusion laboratory managers in the selected hospitals were interviewed in 7 case studies with the aim of identifying drivers for low wastage and good inventory management practice. The findings from the case studies were compared with the literature. The extant literature asserts that the drivers for good inventory performance are the use of complex inventory models and algorithms. This study has found this not to be the case. Instead, good performance is driven by the quality of transfusion laboratory staff, who must be skilled, regularly trained, and experienced. Electronic crossmatching, transparency of the inventory, and simple management procedures also facilitate good performance. Copyright © 2012 Elsevier Inc. All rights reserved.

Linkage between company scores and stock returns

Directory of Open Access Journals (Sweden)

Saban Celik

2017-12-01

Full Text Available Previous studies on company scores conducted at firm-level, generally concluded that there exists a positive relation between company scores and stock returns. Motivated by these studies, this study examines the relationship between company scores (Corporate Governance Score, Economic Score, Environmental Score, and Social Score and stock returns, both at portfolio-level analysis and firm-level cross-sectional regressions. In portfolio-level analysis, stocks are sorted based on each company scores and quintile portfolio are formed with different levels of company scores. Then, existence and significance of raw returns and risk-adjusted returns difference between portfolios with the extreme company scores (portfolio 10 and portfolio 1 is tested. In addition, firm-level cross-sectional regression is performed to examine the significance of company scores effects with control variables. While portfolio-level analysis results indicate that there is no significant relation between company scores and stock returns; firm-level analysis indicates that economic, environmental, and social scores have effect on stock returns, however, significance and direction of these effects change, depending on the included control variables in the cross-sectional regression.

Dynamic Estimation on Output Elasticity of Highway Capital Stock in China

Science.gov (United States)

Li, W. J.; Zuo, Q. L.; Bai, Y. F.

2017-12-01

By using the Perpetual Inventory Method to calculate the capital stock of highway in China from 1988 to 2016, the paper builds the State Space Model based on Translog Production Function, according to the Ridge Regression and Kalman Filter Method, the dynamic estimation results of output elasticity are measured continuously and analyzed. The conclusions show that: Firstly, China’s growth speed on highway industry capital stock are divided into three stages which are respectively from 1988 to 2000, from 2001 to 2009 and from 2010 to 2016, during which shows steady growth, between which reflect rapid growth; Secondly, the output elasticity of highway capital stock, being between 0.154 and 0.248, is slightly larger than the output elasticity of human input factor, lower than the output elasticity of the technical level, shows positive effect on transport economy and rises steadily, but the output efficiency is low on the whole; Thirdly, around the year of 2010, the scale pay on highway industry begins to highlight the characteristic of increase.

Price Earnings Ratio and Stock Return Analysis (Evidence from Liquidity 45 Stocks Listed in Indonesia Stock Exchange

Directory of Open Access Journals (Sweden)

Liem Pei Fun

2012-01-01

Full Text Available Price to Earnings Ratio (PE Ratio has been broadly used by analysts and investors for stock selection. Stocks with low PE ratio are perceived as having cheaper current price hence expected to generate higher return in subsequent period. This paper aims to examine predictability of stock return using PE Ratio based on historical relationship between PE Ratio and subsequent stock return. Particularly, it seeks to find whether stocks with high PE Ratio followed by low stocks return and on the contrary, stocks with low PE Ratio followed by high stocks return. Using stocks which are included as member of Liquidity 45 and observation period 2005-2010 as samples, results show that there is significance difference between low PE and high PE portfolio stock return in short term (holding period of 6 months but there is no significance difference between both portfolio stock return if they are hold for one, two, three, and four years. This research also finds that there is no significant relationship between stock return and (trailing PE Ratio which suggests that (trailing PE Ratio is not useful in estimating both short term and long term stock returns

Trading network predicts stock price.

Science.gov (United States)

Sun, Xiao-Qian; Shen, Hua-Wei; Cheng, Xue-Qi

2014-01-16

Stock price prediction is an important and challenging problem for studying financial markets. Existing studies are mainly based on the time series of stock price or the operation performance of listed company. In this paper, we propose to predict stock price based on investors' trading behavior. For each stock, we characterize the daily trading relationship among its investors using a trading network. We then classify the nodes of trading network into three roles according to their connectivity pattern. Strong Granger causality is found between stock price and trading relationship indices, i.e., the fraction of trading relationship among nodes with different roles. We further predict stock price by incorporating these trading relationship indices into a neural network based on time series of stock price. Experimental results on 51 stocks in two Chinese Stock Exchanges demonstrate the accuracy of stock price prediction is significantly improved by the inclusion of trading relationship indices.

Inventory classification based on decoupling points

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Joakim Wikner

2015-01-01

Full Text Available The ideal state of continuous one-piece flow may never be achieved. Still the logistics manager can improve the flow by carefully positioning inventory to buffer against variations. Strategies such as lean, postponement, mass customization, and outsourcing all rely on strategic positioning of decoupling points to separate forecast-driven from customer-order-driven flows. Planning and scheduling of the flow are also based on classification of decoupling points as master scheduled or not. A comprehensive classification scheme for these types of decoupling points is introduced. The approach rests on identification of flows as being either demand based or supply based. The demand or supply is then combined with exogenous factors, classified as independent, or endogenous factors, classified as dependent. As a result, eight types of strategic as well as tactical decoupling points are identified resulting in a process-based framework for inventory classification that can be used for flow design.

Implementing structure and control over unofficial inventories in a multispecialty group practice.

Science.gov (United States)

Gall, M

1994-02-01

Materiel managers have been in control of most aspects of the supply chain except for the inventories of the end users, which account for 70 percent of the inventory supply dollars. When the Materials Manager at Lexington Clinic in Lexington, Kentucky, was approached by the Clinic's Chief Executive Officer to implement cost containment measures, the Materials Manager seized the opportunity to implement a six-step program aimed at controlling those supply dollars. Through requisition training, enforcing approval levels, limiting the number of requisitioners, and establishing par levels on floor inventories, the clinic's "unofficial" inventory supply dollars were reduced by 7 percent in the first 12 departments where the par levels were established. The program was hailed as a tremendous success and a positive experience for everyone, from nurses to warehouse clerks.

A systems approach to inventory management of repairables in the Navy

OpenAIRE

Apple, Chris Leon

1985-01-01

Approved for public release; distribution is unlimited This thesis develops an inventory model for repairable items which integrates the shipboard protection level into the wholesale stock level computations. It uses mean supply response time (MSRT) as its measure of effectiveness and provides methods for computing either the required wholesale stock level given a MSRT goal or for minimizing the system MSRT subject to budgetary constraints. Examples are provided which demons...

Heat transport inventory monitoring for CANDU-PHW reactors

International Nuclear Information System (INIS)

Hussein, E.; Luxat, J.C.

1984-01-01

A computer-based D 2 O coolant inventory monitoring system proposed for implementation on the digital computer controllers at Ontario Hydro's CANDU generating units is discussed. By monitoring process parameters and utilizing probabilistically-based decision algorithms, timely indication of any significant loss of D 2 O inventory will be provided to the operator. The monitoring is performed in a co-ordinated manner such that D 2 O losses from either the heat transport system or the inventory control system can be detected. (orig.)

Standards for large-scale forest inventories. A comparative study for Italy

Directory of Open Access Journals (Sweden)

2004-01-01

Full Text Available A comparison has been made between methodologies for forest inventories in Italy, considering aspects as design, sampling units, attributes, forest definitions, statistical methods, estimation models, information quality. Main differences concern the definition of forest categories and the emphasis given to forest attributes like biodiversity, carbon stock, recreational value, geological instability, forest health, which are all increasingly considered in last generation forest inventories.

Biophysical Controls over Carbon and Nitrogen Stocks in Desert Playa Wetlands

Science.gov (United States)

McKenna, O. P.; Sala, O. E.

2014-12-01

Playas are ephemeral desert wetlands situated at the bottom of closed catchments. Desert playas in the Southwestern US have not been intensively studied despite their potential importance for the functioning of desert ecosystems. We want to know which geomorphic and ecological variables control of the stock size of soil organic carbon, and soil total nitrogen in playas. We hypothesize that the magnitude of carbon and nitrogen stocks depends on: (a) catchment size, (b) catchment slope, (d) catchment vegetation cover, (e) bare-ground patch size, and (f) catchment soil texture. We chose thirty playas from across the Jornada Basin (Las Cruces, NM) ranging from 0.5-60ha in area and with varying catchment characteristics. We used the available 5m digital elevation map (DEM) to calculate the catchment size and catchment slope for these thirty playas. We measured percent cover, and patch size using the point-intercept method with three 10m transects in each catchment. We used the Bouyoucos-hydrometer soil particle analysis to determine catchment soil texture. Stocks of organic carbon and nitrogen were measured from soil samples at four depths (0-10 cm, 10-30 cm, 30-60 cm, 60-100 cm) using C/N combustion analysis. In terms of nitrogen and organic carbon storage, we found soil nitrogen values in the top 10cm ranging from 41.963-214.365 gN/m2, and soil organic carbon values in the top 10cm ranging from 594.339-2375.326 gC/m2. The results of a multiple regression analysis show a positive relationship between catchment slope and both organic carbon and nitrogen stock size (nitrogen: y= 56.801 +47.053, R2=0.621; organic carbon: y= 683.200 + 499.290x, R2= 0.536). These data support our hypothesis that catchment slope is one of factors controlling carbon and nitrogen stock in desert playas. We also applied our model to the 69 other playas of the Jornada Basin and estimated stock sizes (0-10cm) between 415.07-447.97 Mg for total soil nitrogen and 4627.99-5043.51 Mg for soil organic

Control Analysis Of Tobacco Raw Material Supplies Using Eoq Method Economic Order Quantity To Reach Efficiency Total Costs Of Raw Material In Pr. Sukun

Directory of Open Access Journals (Sweden)

Wiwik Sudarwati

2017-07-01

Full Text Available The raw material inventory control system determines and guarantees the availability of raw material stock in the right quantity quality and timing. The problem in this research is the procurement of raw materials of tobacco. PR. Sukun still often experiences the excess. This is related to the frequency of raw material purchases and the quantity of raw material purchases which can lead to waste of working capital embedded in raw material inventory raw material ordering costs and raw material storage costs. The purpose of this research is to know how to make an efficiency level in procurement of raw material inventory between EOQ method compared with policy of PR. Sukun. The type of research used is analytic descriptive type. Data analysis begins by analyzing raw material quantity comparison total raw material inventory cost and raw material cost between PR Sukun policy with EOQ method. Based on the results of research known that by using EOQ method can be much more efficient compared to policy of PR. Sukun. The quantity and frequency of purchasing raw materials is less but still take into account the safety stock and reorder point so the production process is not disturbed. In addition the cost of purchasing ordering costs and raw materials storage costs less so as to create efficiencies on the cost of raw materials inventory. PR. Sukun in the procurement of raw material inventory should use EOQ method to be more efficient and take into account the safety stock and reorder point to avoid the inventory excess of raw materials.

Fuzzy time-series based on Fibonacci sequence for stock price forecasting

Science.gov (United States)

Chen, Tai-Liang; Cheng, Ching-Hsue; Jong Teoh, Hia

2007-07-01

Time-series models have been utilized to make reasonably accurate predictions in the areas of stock price movements, academic enrollments, weather, etc. For promoting the forecasting performance of fuzzy time-series models, this paper proposes a new model, which incorporates the concept of the Fibonacci sequence, the framework of Song and Chissom's model and the weighted method of Yu's model. This paper employs a 5-year period TSMC (Taiwan Semiconductor Manufacturing Company) stock price data and a 13-year period of TAIEX (Taiwan Stock Exchange Capitalization Weighted Stock Index) stock index data as experimental datasets. By comparing our forecasting performances with Chen's (Forecasting enrollments based on fuzzy time-series. Fuzzy Sets Syst. 81 (1996) 311-319), Yu's (Weighted fuzzy time-series models for TAIEX forecasting. Physica A 349 (2004) 609-624) and Huarng's (The application of neural networks to forecast fuzzy time series. Physica A 336 (2006) 481-491) models, we conclude that the proposed model surpasses in accuracy these conventional fuzzy time-series models.

Inventory management and control at the central distribution center for Univar Products International B.V.

NARCIS (Netherlands)

Pholnukulkit, Pimara

2008-01-01

This report presents the outcome of the Logistics Design Project carried out for Univar Products International B.V. The goal of this project is to design an inventory control system and implement an inventory control tool that supports decisions in managing inventory of all products in the central

IMPROVEMENT OF THE METHODS OF INTERNAL CONTROL OF INVENTORIES IN AGRICULTURAL ORGANIZATIONS

OpenAIRE

Afanasenko A. N.

2013-01-01

The article considers the necessity of inventories for any organization. The fate of the organization depends on its management effectiveness and its financial position. The organizational peculiarities of internal control in the agricultural sphere have been studied and the ways of improvement of the organizational and methodological mechanisms have been offered for the internal control of inventories in agricultural organizations

A remote sensing-based model of tidal marsh aboveground carbon stocks for the conterminous United States

Science.gov (United States)

Byrd, Kristin B.; Ballanti, Laurel; Thomas, Nathan; Nguyen, Dung; Holmquist, James R.; Simard, Marc; Windham-Myers, Lisamarie

2018-01-01

Remote sensing based maps of tidal marshes, both of their extents and carbon stocks, have the potential to play a key role in conducting greenhouse gas inventories and implementing climate mitigation policies. Our objective was to generate a single remote sensing model of tidal marsh aboveground biomass and carbon that represents nationally diverse tidal marshes within the conterminous United States (CONUS). We developed the first calibration-grade, national-scale dataset of aboveground tidal marsh biomass, species composition, and aboveground plant carbon content (%C) from six CONUS regions: Cape Cod, MA, Chesapeake Bay, MD, Everglades, FL, Mississippi Delta, LA, San Francisco Bay, CA, and Puget Sound, WA. Using the random forest machine learning algorithm, we tested whether imagery from multiple sensors, Sentinel-1 C-band synthetic aperture radar, Landsat, and the National Agriculture Imagery Program (NAIP), can improve model performance. The final model, driven by six Landsat vegetation indices and with the soil adjusted vegetation index as the most important (n = 409, RMSE = 310 g/m2, 10.3% normalized RMSE), successfully predicted biomass for a range of marsh plant functional types defined by height, leaf angle and growth form. Model results were improved by scaling field-measured biomass calibration data by NAIP-derived 30 m fraction green vegetation. With a mean plant carbon content of 44.1% (n = 1384, 95% C.I. = 43.99%–44.37%), we generated regional 30 m aboveground carbon density maps for estuarine and palustrine emergent tidal marshes as indicated by a modified NOAA Coastal Change Analysis Program map. We applied a multivariate delta method to calculate uncertainties in regional carbon densities and stocks that considered standard error in map area, mean biomass and mean %C. Louisiana palustrine emergent marshes had the highest C density (2.67 ± 0.004 Mg/ha) of all regions, while San Francisco Bay brackish/saline marshes had

Improved management based on stock identification of eastern and western Baltic cod

DEFF Research Database (Denmark)

Hüssy, Karin; Bastardie, Francois; Eero, Margit

The objective of this project was to establish an empirically founded knowledge base for the sustainable exploitation of the western Baltic cod stock by including the complex stock structure and migration patterns. Stock mapping: Extensive immigration of “Eastern” cod into the Arkona Basin (SD 24......) within the “Western” cod’s management unit was documented using high-powered genetic tools. The majority (91%) of all spawning fish caught in SD 24 in 2011 were “Eastern” cod and only 9% were from the “Western” stock. The results suggest that the stock structure in the Arkona Basin is highly influenced...... by mixing of genetically separate stocks. Trends in mixing: Since the 1980’s where cod in SD 24 consisted primarily of “Western” type, the proportion of “Eastern” cod has increased, particularly since 2005. Throughout that period, the immigration of “Eastern” cod into SD 24 consisted primarily of adult...

Consumer responses to shelf-out-of-stocks of perishable products

NARCIS (Netherlands)

Woensel, van T.; Donselaar, van K.H.; Broekmeulen, R.A.C.M.; Fransoo, J.C.

2007-01-01

This paper aims to identify customer behavior with regard to out-of-stocks (OOS) of perishable products (focused on bakery bread) and the resulting inventory performance for these perishable products. Design/methodology/approach – Insights on how consumers behave when their preferred bread product

PERANCANGAN SISTEM INFORMASI SEBAGAI ALAT BANTU PENGAMBILAN KEPUTUSAN DALAM PENGONTROLAN PERSEDIAAN RETAIL ELEKTONIK

Directory of Open Access Journals (Sweden)

Sri Hartini

2013-03-01

Full Text Available Sebagian besar retail elektronik melakukan pengambilan keputusan dalam hal pengontrolan inventori berdasarkan intuisi tanpa dukungan database elektronik yang valid. Hal tersebut sering mengakibatkan terjadinya lost sales, karena tidak ada barang di gudang ketika ada permintaan.  Guna mengatasi permasalahan sistem inventori tersebut, peneliti mencoba mengembangkan Sistem Informasi Inventori yang dapat membantu perusahaan. Sistem informasi yang bersifat web-based membuat staff di masing-masing bagian dapat melihat tingkat stok yang akurat di tiap gudang. Manfaat yang dirasakan terutama bagi pemilik/owner yaitu mendapat perkiraan demand di masa mendatang melalui peramalan serta memperoleh usulan bagaimana mengontrol persediaan melalui tingkat safety stock, reorder point, quantity, dan frekuensi pesan yang disarankan. Kata kunci :  inventori,  peramalan, web-based, sistem informasi, retail elektronik   Abstract Most electronics retailers make decisions in terms of inventory control based on intuition without a valid electronic database support. This often resulted in lost sales, as no goods in the warehouse when there is demand. To overcome the problems of inventory system, researchers are trying to develop Inventory Information System that can help the company. Information systems that are web-based to make staff in each section can see accurate stock levels at each warehouse. Perceived benefits, especially for owners / owner that gets the estimated future demand through forecasting and obtaining suggestions how to control inventory through level safety stock, reorder point, quantity, and frequency of the message suggested. Keywords: inventory, forecasting, web-based, information systems, electronic retail

An inventory control project in a major Danish company using compound renewal demand models

DEFF Research Database (Denmark)

Larsen, Christian; Seiding, Claus Hoe; Teller, Christian

2008-01-01

procedures for determining suitable inventory control variables based on the fitted demand distributions and a service-level requirement stated in terms of an order fill rate. Finally, we validated the results of our models against the procedures that had been in use in the company. It was concluded...

QUANTIFICATION OF THE DECISIONS OF CONTROL AND AUDIT IN INVENTORY MANAGEMENT IN CEMENT INDUSTRY ENTERPRISES

OpenAIRE

Sylwia £êgowik-Œwi¹cik

2011-01-01

Inventory management in enterprises of cement industry necessitates the assessment of the level of risk which is generated by production inventory. The processes of control and auditing allow for planning, monitoring and organization of inventory management in the analysed business entities. This paper is aimed at presentation of the phase of preparation of audit activities in the area of inventory and verification of model solutions for the processes of control and audit in terms of inventor...

Stock Versus CAD/CAM Customized Zirconia Implant Abutments – Clinical and Patient‐Based Outcomes in a Randomized Controlled Clinical Trial

Science.gov (United States)

Meijer, Henny J.A.; Kerdijk, Wouter; Raghoebar, Gerry M.; Cune, Marco

2016-01-01

Abstract Background Single‐tooth replacement often requires a prefabricated dental implant and a customized crown. The benefits of individualization of the abutment remain unclear. Purpose This randomized controlled clinical trial aims to study potential benefits of individualization of zirconia implant abutments with respect to preservation of marginal bone level and several clinical and patient‐based outcome measures. Material and Methods Fifty participants with a missing premolar were included and randomly assigned to standard (ZirDesign, DentsplySirona Implants, Mölndal, Sweden) or computer aided design/computer aided manufacturing (CAD/CAM) customized (Atlantis, DentsplySirona Implants, Mölndal, Sweden) zirconia abutment therapy. Peri‐implant bone level (primary outcome), Plaque‐index, calculus formation, bleeding on probing, gingiva index, probing pocket depth, recession, appearance of soft tissues and patients' contentment were assessed shortly after placement and one year later. Results No implants were lost and no complications related to the abutments were observed. Statistically significant differences between stock and CAD/CAM customized zirconia abutments could not be demonstrated for any of the operationalized variables. Conclusion The use of a CAD/CAM customized zirconia abutment in single tooth replacement of a premolar is not associated with an improvement in clinical performance or patients' contentment when compared to the use of a stock zirconia abutment. PMID:27476829

DEVELOPMENT OF A SPREADSHEET BASED VENDOR MANAGED INVENTORY MODEL FOR A SINGLE ECHELON SUPPLY CHAIN: A CASE STUDY

Directory of Open Access Journals (Sweden)

Karanam Prahlada Rao

2010-11-01

Full Text Available Vendor managed inventory (VMI is a supply chain initiative where the supplier assumes the responsibility for managing inventories using advanced communication means such as online messaging and data retrieval system. A well collaborated vendor manage inventory system can improve supply chain performance by decreasing the inventory level and increasing the fill rate. This paper investigates the implementation of vendor managed inventory systems in a consumer goods industry. We consider (r, Q policy for replenishing its inventory. The objective of work is to minimize the inventory across the supply chain and maximize the service level. The major contribution of this work is to develop a spreadsheet model for VMI system, Evaluation of Total inventory cost by using spreadsheet based method and Analytical method, Quantifying inventory reduction, Estimating service efficiency level, and validating the VMI spread sheet model with randomly generated demand. In the application, VMI as an inventory control system is able to reduce the inventory cost without sacrificing the service level. The results further more show that the inventory reduction obtained from analytical method is closer to the spread sheet based approach, which reveals the VMI success. However the VMI success is impacted by the quality of buyersupplier relationships, the quality of the IT system and the intensity of information sharing, but not by the quality of information shared.

Reducing uncertainty for estimating forest carbon stocks and dynamics using integrated remote sensing, forest inventory and process-based modeling

Science.gov (United States)

Poulter, B.; Ciais, P.; Joetzjer, E.; Maignan, F.; Luyssaert, S.; Barichivich, J.

2015-12-01

Accurately estimating forest biomass and forest carbon dynamics requires new integrated remote sensing, forest inventory, and carbon cycle modeling approaches. Presently, there is an increasing and urgent need to reduce forest biomass uncertainty in order to meet the requirements of carbon mitigation treaties, such as Reducing Emissions from Deforestation and forest Degradation (REDD+). Here we describe a new parameterization and assimilation methodology used to estimate tropical forest biomass using the ORCHIDEE-CAN dynamic global vegetation model. ORCHIDEE-CAN simulates carbon uptake and allocation to individual trees using a mechanistic representation of photosynthesis, respiration and other first-order processes. The model is first parameterized using forest inventory data to constrain background mortality rates, i.e., self-thinning, and productivity. Satellite remote sensing data for forest structure, i.e., canopy height, is used to constrain simulated forest stand conditions using a look-up table approach to match canopy height distributions. The resulting forest biomass estimates are provided for spatial grids that match REDD+ project boundaries and aim to provide carbon estimates for the criteria described in the IPCC Good Practice Guidelines Tier 3 category. With the increasing availability of forest structure variables derived from high-resolution LIDAR, RADAR, and optical imagery, new methodologies and applications with process-based carbon cycle models are becoming more readily available to inform land management.

Comparative Analysis of Investment Funds Stocks-based Portfolios and BET Stocks-based Portfolios

Directory of Open Access Journals (Sweden)

Ion STANCU

2010-04-01

Full Text Available In this paper we intend to find out what is the best choice of stocks-based portfolio. The major goal is to find whether is more efficient to invest the whole capital in a single sector, like financial investments, or to create a diversified portfolio, taking into account assets from various economic sectors. Capital allocation will be based on the concept of cointegration. We have chosen this method because it can be applied on non-stationary data series, and, besides, it has the advantage of using the whole set of information provided by the financial assets. Another goal is to study how the portfolio structure adjusts if a shock occurs during the period under analysis so that to preserve a certain return or minimize a potential loss. The study will result in an investment solution in the Romanian capital market, even in the context of financial crisis.

Emissions inventories and options for control SUMMARY REPORT

NARCIS (Netherlands)

Swart RJ; Amstel AR van; Born GJ van den; Kroeze C; MTV; LAE

1994-01-01

This report is the final summary report of the project "Social causes of the greenhouse effect ; emissions inventories and options for control", funded by the National Research Programme on Global Air Pollution and Climate Change (NRP) and the Environment Directorate of the Ministry of Housing,

Prevention of deep vein thrombosis in potential neurosurgical patients. A randomized trial comparing graduated compression stockings alone or graduated compression stockings plus intermittent pneumatic compression with control

International Nuclear Information System (INIS)

Turpie, A.G.; Hirsh, J.; Gent, M.; Julian, D.; Johnson, J.

1989-01-01

In a randomized trial of neurosurgical patients, groups wearing graduated compression stockings alone (group 1) or graduated compression stockings plus intermittent pneumatic compression (IPC) (group 2) were compared with an untreated control group in the prevention of deep vein thrombosis (DVT). In both active treatment groups, the graduated compression stockings were continued for 14 days or until hospital discharge, if earlier. In group 2, IPC was continued for seven days. All patients underwent DVT surveillance with iodine 125-labeled fibrinogen leg scanning and impedance plethysmography. Venography was carried out if either test became abnormal. Deep vein thrombosis occurred in seven (8.8%) of 80 patients in group 1, in seven (9.0%) of 78 patients in group 2, and in 16 (19.8%) of 81 patients in the control group. The observed differences among these rates are statistically significant. The results of this study indicate that graduated compression stockings alone or in combination with IPC are effective methods of preventing DVT in neurosurgical patients

Digital Mapping of Soil Organic Carbon Contents and Stocks in Denmark

DEFF Research Database (Denmark)

Adhikari, Kabindra; Hartemink, Alfred E.; Minasny, Budiman

2014-01-01

Estimation of carbon contents and stocks are important for carbon sequestration, greenhouse gas emissions and national carbon balance inventories. For Denmark, we modeled the vertical distribution of soil organic carbon (SOC) and bulk density, and mapped its spatial distribution at five standard ...

Retail inventory management with lost sales

NARCIS (Netherlands)

Curseu - Stefanut, A.

2012-01-01

The inventory control problem of traditional store-based grocery retailers has several challenging features. Demand for products is stochastic, and is typically lost when no inventory is available on the shelves. As the consumer behavior studies reveal, only a small percentage of customers are

Adding trend data to Depletion-Based Stock Reduction Analysis

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A Bayesian model of Depletion-Based Stock Reduction Analysis (DB-SRA), informed by a time series of abundance indexes, was developed, using the Sampling Importance...

The Evaluation of Internal Control Implementation Over Merchandise Inventory at PT. Suramando (Pharmaceutical Distributors and General Suppliers) in Manado

OpenAIRE

Runtu, Treesje; Seredei, Srijantri

2015-01-01

Inventory is a firms current assets, that its amount is material and constituting one of essential factor in the corporate operational activity. That is why a good internal controls to must be done secure supplies from the acts of fraud, deviation and damage. The purpose of this study is to evaluate the internal control over merchandise inventory at PT. Suramando it is running well. The method used is qualitative method through descriptive analysis. The final conclusion is that based on the e...

ENGINEERING-TO-ORDER VERSUS MAKE-TO-STOCK STRATEGY: AN ANALYSIS AT TWO PRINTING COMPANIES

Directory of Open Access Journals (Sweden)

Paulo Cesar Chagas Rodrigues

2010-09-01

Full Text Available Organizations are adopting industrial production models with priority given to reducing costs and increasing the quality of their processes and products. Optimizing and rationalization the inventory management is a great opportunity for these companies conquer these goals. The objective of this paper is to analyze inventory management at two printing companies located in the region of Bauru, where one adopts the Engineering-To-Order (ETO production system and the other the Make-To-Stock (MTS production system, highlighting their convergences and oppositions. For their achievement was chosen by the methodology of study of multiple cases (two cases. Data were collected through the intersection of the following tools: semi-structure, document analysis and observation in loco. Revisions are made in theoretical work on the following topics: logistics, management of materials and production planning and control. These themes guided the search, allowing a greatest criticism about the collected data and information generated. The two case studies were presented together with a comparative table of the main aspects of the influence of demand management strategy on the inventory management in two companies. Although the companies adopt different production strategies, there was no significant change observed in inventory management strategy.

Asymmetric multi-fractality in the U.S. stock indices using index-based model of A-MFDFA

International Nuclear Information System (INIS)

Lee, Minhyuk; Song, Jae Wook; Park, Ji Hwan; Chang, Woojin

2017-01-01

Highlights: • ‘Index-based A-MFDFA’ model is proposed to assess the asymmetric multi-fractality. • The asymmetric multi-fractality in the U.S. stock indices are investigated using ‘Index-based’ and ‘Return-based’ A-MFDFA. • The asymmetric feature is more significantly identified by ‘Index-based’ model than ‘return-based’ model. • Source of multi-fractality and time-varying features are analyzed. - Abstract: We detect the asymmetric multi-fractality in the U.S. stock indices based on the asymmetric multi-fractal detrended fluctuation analysis (A-MFDFA). Instead using the conventional return-based approach, we propose the index-based model of A-MFDFA where the trend based on the evolution of stock index rather than stock price return plays a role for evaluating the asymmetric scaling behaviors. The results show that the multi-fractal behaviors of the U.S. stock indices are asymmetric and the index-based model detects the asymmetric multi-fractality better than return-based model. We also discuss the source of multi-fractality and its asymmetry and observe that the multi-fractal asymmetry in the U.S. stock indices has a time-varying feature where the degree of multi-fractality and asymmetry increase during the financial crisis.

Cointegration-based financial networks study in Chinese stock market

Science.gov (United States)

Tu, Chengyi

2014-05-01

We propose a method based on cointegration instead of correlation to construct financial complex network in Chinese stock market. The network is obtained starting from the matrix of p-value calculated by Engle-Granger cointegration test between all pairs of stocks. Then some tools for filtering information in complex network are implemented to prune the complete graph described by the above matrix, such as setting a level of statistical significance as a threshold and Planar Maximally Filtered Graph. We also calculate Partial Correlation Planar Graph of these stocks to compare the above networks. Last, we analyze these directed, weighted and non-symmetric networks by using standard methods of network analysis, including degree centrality, PageRank, HITS, local clustering coefficient, K-shell and strongly and weakly connected components. The results shed a new light on the underlying mechanisms and driving forces in a financial market and deepen our understanding of financial complex network.

Using the Stock Market to Teach Physics

Science.gov (United States)

Faux, David A.; Hearn, Stephen

2004-11-01

Students are interested in money. Personal finance is an important issue for most students, especially as they move into university education and take a greater control of their own finances. Many are also interested in stock markets and their ability to allow someone to make, and lose, large sums of money, with their interest fueled by the boom in technology-based stocks of 2000/2001 followed by their subsequent dramatic collapse and the publicizing of so-called "rogue-traders." There is also a much greater ownership of stocks by families following public offerings, stock-based savings products, and the ability to trade stocks online. Consequently, there has been a steady growth of finance and finance-related courses available within degree programs in response to the student demand, with many students motivated by the huge salaries commanded by those with a successful career in the financial sector. We report here details of a joint project between Charterhouse School and the University of Surrey designed to exploit the excitement of finance to teach elements of the high school (age 16-18) curriculum through modeling and simulation.

Word of Mouth : An Agent-based Approach to Predictability of Stock Prices

Science.gov (United States)

Shimokawa, Tetsuya; Misawa, Tadanobu; Watanabe, Kyoko

This paper addresses how communication processes among investors affect stock prices formation, especially emerging predictability of stock prices, in financial markets. An agent based model, called the word of mouth model, is introduced for analyzing the problem. This model provides a simple, but sufficiently versatile, description of informational diffusion process and is successful in making lucidly explanation for the predictability of small sized stocks, which is a stylized fact in financial markets but difficult to resolve by traditional models. Our model also provides a rigorous examination of the under reaction hypothesis to informational shocks.

41 CFR 101-26.606 - Supply support available from the inventory control points of the military departments.

Science.gov (United States)

2010-07-01

... from the inventory control points of the military departments. 101-26.606 Section 101-26.606 Public... § 101-26.606 Supply support available from the inventory control points of the military departments. Federal civil agencies may obtain items of supply which are procured and managed by the inventory control...

Digital mapping of soil organic carbon contents and stocks in Denmark.

Science.gov (United States)

Adhikari, Kabindra; Hartemink, Alfred E; Minasny, Budiman; Bou Kheir, Rania; Greve, Mette B; Greve, Mogens H

2014-01-01

Estimation of carbon contents and stocks are important for carbon sequestration, greenhouse gas emissions and national carbon balance inventories. For Denmark, we modeled the vertical distribution of soil organic carbon (SOC) and bulk density, and mapped its spatial distribution at five standard soil depth intervals (0-5, 5-15, 15-30, 30-60 and 60-100 cm) using 18 environmental variables as predictors. SOC distribution was influenced by precipitation, land use, soil type, wetland, elevation, wetness index, and multi-resolution index of valley bottom flatness. The highest average SOC content of 20 g kg(-1) was reported for 0-5 cm soil, whereas there was on average 2.2 g SOC kg(-1) at 60-100 cm depth. For SOC and bulk density prediction precision decreased with soil depth, and a standard error of 2.8 g kg(-1) was found at 60-100 cm soil depth. Average SOC stock for 0-30 cm was 72 t ha(-1) and in the top 1 m there was 120 t SOC ha(-1). In total, the soils stored approximately 570 Tg C within the top 1 m. The soils under agriculture had the highest amount of carbon (444 Tg) followed by forest and semi-natural vegetation that contributed 11% of the total SOC stock. More than 60% of the total SOC stock was present in Podzols and Luvisols. Compared to previous estimates, our approach is more reliable as we adopted a robust quantification technique and mapped the spatial distribution of SOC stock and prediction uncertainty. The estimation was validated using common statistical indices and the data and high-resolution maps could be used for future soil carbon assessment and inventories.

Underestimation of boreal soil carbon stocks by mathematical soil carbon models linked to soil nutrient status

Science.gov (United States)

Ťupek, Boris; Ortiz, Carina A.; Hashimoto, Shoji; Stendahl, Johan; Dahlgren, Jonas; Karltun, Erik; Lehtonen, Aleksi

2016-08-01

Inaccurate estimate of the largest terrestrial carbon pool, soil organic carbon (SOC) stock, is the major source of uncertainty in simulating feedback of climate warming on ecosystem-atmosphere carbon dioxide exchange by process-based ecosystem and soil carbon models. Although the models need to simplify complex environmental processes of soil carbon sequestration, in a large mosaic of environments a missing key driver could lead to a modeling bias in predictions of SOC stock change.We aimed to evaluate SOC stock estimates of process-based models (Yasso07, Q, and CENTURY soil sub-model v4) against a massive Swedish forest soil inventory data set (3230 samples) organized by a recursive partitioning method into distinct soil groups with underlying SOC stock development linked to physicochemical conditions.For two-thirds of measurements all models predicted accurate SOC stock levels regardless of the detail of input data, e.g., whether they ignored or included soil properties. However, in fertile sites with high N deposition, high cation exchange capacity, or moderately increased soil water content, Yasso07 and Q models underestimated SOC stocks. In comparison to Yasso07 and Q, accounting for the site-specific soil characteristics (e. g. clay content and topsoil mineral N) by CENTURY improved SOC stock estimates for sites with high clay content, but not for sites with high N deposition.Our analysis suggested that the soils with poorly predicted SOC stocks, as characterized by the high nutrient status and well-sorted parent material, indeed have had other predominant drivers of SOC stabilization lacking in the models, presumably the mycorrhizal organic uptake and organo-mineral stabilization processes. Our results imply that the role of soil nutrient status as regulator of organic matter mineralization has to be re-evaluated, since correct SOC stocks are decisive for predicting future SOC change and soil CO2 efflux.

Integral inventory control in spare parts networks with capacity restrictions

NARCIS (Netherlands)

Sleptchenko, Andrei

2002-01-01

Integral inventory control of repairable items in service networks can result in a significant gain compared to traditional local control mechanisms, in terms of both efficiency and customer service. Research on quantitative decision support models has yielded various useful results. However, in

A consumption-based GHG inventory for the U.S. state of Oregon.

Science.gov (United States)

Erickson, Peter; Allaway, David; Lazarus, Michael; Stanton, Elizabeth A

2012-04-03

Many U.S. states conduct greenhouse gas (GHG) inventories to inform their climate change planning efforts. These inventories usually follow a production-based method adapted from the Intergovernmental Panel on Climate Change. States could also take a consumption-based perspective, however, and estimate all emissions released to support consumption in their state, regardless of where the emissions occur. In what may be the first such comprehensive inventory conducted for a U.S. state, we find that consumption-based emissions for Oregon are 47% higher than those released in-state. This finding implies that Oregon's contribution to global greenhouse gas emissions (carbon footprint) is considerably higher than traditional production-based methods would suggest. Furthermore, the consumption-based inventory helps highlight the role of goods and services (and associated purchasing behaviors) more so than do production-based methods. Accordingly, a consumption-based perspective opens new opportunities for many states and their local government partners to reduce GHG emissions, such as initiatives to advance lower-carbon public sector or household consumption, that are well within their sphere of influence. State and local governments should consider conducting consumption-based GHG inventories and adopting consumption-based emission reductions targets in order to broaden the reach and effectiveness of state and local actions in reducing global GHG emissions. Consumption-based frameworks should be viewed as a complement to, but not a substitute for, production-based (in-state) GHG emissions inventories and targets.

Testing for change in structural elements of forest inventories

Science.gov (United States)

Melinda Vokoun; David Wear; Robert Abt

2009-01-01

In this article we develop a methodology to test for changes in the underlying relationships between measures of forest productivity (structural elements) and site characteristics, herein referred to as structural changes, using standard forest inventories. Changes in measures of forest growing stock volume and number of trees for both...

Implementation and evaluation of a web based system for pharmacy stock management in rural Haiti.

Science.gov (United States)

Berger, Elisabeth J; Jazayeri, Darius; Sauveur, Marcel; Manasse, Jean Joel; Plancher, Inel; Fiefe, Marquise; Laurat, Guerline; Joseph, Samahel; Kempton, Kathryn; Fraser, Hamish S F

2007-10-11

Managing the stock and supply of medication is essential for the provision of health care, especially in resource poor areas of the world. We have developed an innovative, web-based stock management system to support nine clinics in rural Haiti. Building on our experience with a web-based EMR system for our HIV patients, we developed a comprehensive stock tracking system that is modeled on the appearance of standardized WHO stock cards. The system allows pharmacy staff at all clinics to enter stock levels and also to request drugs and track shipments. Use of the system over the last 2 years has increased rapidly and we now track 450 products supporting care for 1.78 million patient visits annually. Over the last year drug stockouts have fallen from 2.6% to 1.1% and 97% of stock requests delivered were shipped within 1 day. We are now setting up this system in our clinics in rural Rwanda.

A New Approach to Site Demand-Based Level Inventory Optimization

Science.gov (United States)

2016-06-01

Note: If probability distributions are estimated based on mean and variance , use ˆ qix  and 2ˆ( )qi to generate these. q in , number of...TO SITE DEMAND-BASED LEVEL INVENTORY OPTIMIZATION by Tacettin Ersoz June 2016 Thesis Advisor: Javier Salmeron Second Reader: Emily...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE A NEW APPROACH TO SITE DEMAND-BASED LEVEL INVENTORY OPTIMIZATION 5. FUNDING NUMBERS 6

Jakarta Islamic Index-L 45: Rate Financial Performance, Beta Stocks and Stock Price in Indonesian Stock Exchange

Directory of Open Access Journals (Sweden)

Tajus Subqi

2016-08-01

Full Text Available This research had analyzed the effect of financial performance and stock beta (systematic risk towards stock price of eight listed companies in Jakarta Islamic Index (JII – LQ 45 for the time period of 2012-2014. The data was gathered by employing literature study and documentation of financial statements. Multiple regressions are used to measure the effect of independent variable towards dependent variable along with ttest and F test. The results based on overall test suggested that only ROE and NPM had opposite direction correlation with the stock price, meanwhile other variables had positive direction correlation. From partial test with 5% level of significance, only EPS and PER had significant effect on stock price while other variables had no effect.   Keywords: financial performance analysis, stock price, stock beta (systematic risk, Jakarta Islamic Index

Condition based spare parts supply

NARCIS (Netherlands)

Lin, X.; Basten, Robertus Johannes Ida; Kranenburg, A.A.; van Houtum, Geert-Jan

2012-01-01

We consider a spare parts stock point that serves an installed base of machines. Each machine contains the same critical component, whose degradation behavior is described by a Markov process. We consider condition based spare parts supply, and show that an optimal, condition based inventory policy

Effects of control technology on the projected krypton-85 environmental inventory

International Nuclear Information System (INIS)

Oscarson, E.E.

1973-01-01

Growth projections for the USA nuclear power industry may be used to make projections of future radioactive material inventories available for potential release to the environment. Since krypton-85 is produced in reactors, the potential routes of release to the environment are at the reactors or the fuel reprocessing plants. The present generation of reactors and fuel reprocessing plants do not use any systems to limit the release of krypton-85 into the biosphere. Clean-up systems are currently being designed and could be introduced when necessary. The cumulative inventory of krypton-85 in the environment is dependent upon the time of introduction of these clean-up systems and their efficiencies, in addition to the total quantity produced. Annual and cumulative inventories of krypton-85 are projected to increase dramatically over the next 50 years. If controls are assumed to be initiated at various years, a series of graphs of different cumulative environmental inventories and the associated doses and health effects are drawn. Varying the year of introduction and the efficiency of these systems allows one to speculate as to the optimum time for control implementation

Determinants of Stock Price Movements: Evidence from Chittagong Stock Exchange, Bangladesh

Directory of Open Access Journals (Sweden)

Mohammed Syedul Islam

2015-01-01

Full Text Available Stock market plays a vital role in the economic development of an economy. It bridges up between savers and real manufacturers by raising funds from investors to companies. This process was broken down due to the 2010-2011 stock market crash in Bangladesh. Though the determinants of stock price have been settled empirically, the current paper aims to reexamine the relationship between stock price, dividend and retained earnings of 29 listed banks of Chittagong Stock Exchange, in the post-crash period. Cross-sectional data were collected from secondary sources. Using linear regression method, the study found that both, dividend and retained earnings of sample banks have strong influence over the stock price, though there was moderate explanatory power of those variables. After reviewing the causes of crisis 2010-2011, this study suggests the following: to control price manipulation, to publish proper financial statement, regulate the dividend policy, to ensure sufficient knowledge among investors, recruit technical expert and ensure proper settlement for transactions, prevent crises of stock market against speculation etc.

By Force of Habit: A Consumption-Based Explanation of Aggregate Stock Market Behavior

OpenAIRE

Campbell, John; Cochrane, John H.

1999-01-01

We present a consumption-based model that explains the procyclical variation of stock prices, the long-horizon predictability of excess stock returns, and the countercyclical variation of stock market volatility. Our model has an i.i.d. consumption growth driving process, and adds a slow-moving external habit to the standard power utility function. The latter feature produces cyclical variation in risk aversion, and hence in the prices of risky assets. Our model also predicts many of the diff...

41 CFR 109-27.5104-5 - Control and issue of stock.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Control and issue of stock. 109-27.5104-5 Section 109-27.5104-5 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT REGULATIONS SUPPLY AND...

Multifractal in Volatility of Family Business Stocks Listed on Casablanca STOCK Exchange

Science.gov (United States)

Lahmiri, Salim

In this paper, we check for existence of multifractal in volatility of Moroccan family business stock returns and in volatility of Casablanca market index returns based on multifractal detrended fluctuation analysis (MF-DFA) technique. Empirical results show strong evidence of multifractal characteristics in volatility series of both family business stocks and market index. In addition, it is found that small variations in volatility of family business stocks are persistent, whilst small variations in volatility of market index are anti-persistent. However, large variations in family business volatility and market index volatility are both anti-persistent. Furthermore, multifractal spectral analysis based results show strong evidence that volatility in Moroccan family business companies exhibits more multifractality than volatility in the main stock market. These results may provide insightful information for risk managers concerned with family business stocks.

Effective inventory management for nuclear power plants

International Nuclear Information System (INIS)

MacFarlane, I.S.

1985-01-01

Effective inventory management plays a major role at nuclear power plants toward achieving a high level of availability in a cost-effective manner. It enables maintenance personnel to obtain the correct parts easily, when needed, and in satisfactory condition to perform as intended. In addition, appropriate controls and documentation ensure parts are being used in the correct equipment application. The following elements of inventory management will help achieve plant availability goals: (1) appropriate inventory levels, (2) preapproved procurement requirements, (3) storage maintenance, (4) documentation of parts, and (5) control of computer data base

The cross-correlation analysis of multi property of stock markets based on MM-DFA

Science.gov (United States)

Yang, Yujun; Li, Jianping; Yang, Yimei

2017-09-01

In this paper, we propose a new method called DH-MXA based on distribution histograms of Hurst surface and multiscale multifractal detrended fluctuation analysis. The method allows us to investigate the cross-correlation characteristics among multiple properties of different stock time series. It may provide a new way of measuring the nonlinearity of several signals. It also can provide a more stable and faithful description of cross-correlation of multiple properties of stocks. The DH-MXA helps us to present much richer information than multifractal detrented cross-correlation analysis and allows us to assess many universal and subtle cross-correlation characteristics of stock markets. We show DH-MXA by selecting four artificial data sets and five properties of four stock time series from different countries. The results show that our proposed method can be adapted to investigate the cross-correlation of stock markets. In general, the American stock markets are more mature and less volatile than the Chinese stock markets.

Comparisons of allometric and climate-derived estimates of tree coarse root carbon stocks in forests of the United States

Science.gov (United States)

Matthew B. Russell; Grant M. Domke; Christopher W. Woodall; Anthony W. D' Amato

2015-01-01

Background: Refined estimation of carbon (C) stocks within forest ecosystems is a critical component of efforts to reduce greenhouse gas emissions and mitigate the effects of projected climate change through forest C management. Specifically, belowground C stocks are currently estimated in the United States' national greenhouse gas inventory (US NGHGI) using...

Economic Order Quantity (EOQ) Optimal Control Considering Selling Price and Salesman Initiative Cost

Science.gov (United States)

Hertini, Elis; Anggriani, Nursanti; Mianna, Winda; Supriatna, Asep K.

2018-03-01

Retailers usually offer several types of similar products. A larger number of available stock products in display space will lead consumer to buy more, as well as giving a negative impression on other types of less available products. However, the amount of display space is limited so capacity of carrying the products is limited. Competition among products to increase demand rate is influenced by stock levels available in display space, price and salesmen’s initiative in promoting the products. The Economic Order Quantity (EOQ) to replenish the stock of the product is dependent on the on-hand inventory. Salesman’s initiative also affects maximum profit obtained by the seller. In this paper, Potryagin’s Maximal Principle is used to determine the state of the inventory levels response to control prices of products. Sensitivity analysis of capacity allocation display space is also presented numerically.

Relationships between forest fine and coarse woody debris carbon stocks across latitudinal gradients in the United States as an indicator of climate change effects

Science.gov (United States)

C.W. Woodall; G.C. Liknes

2008-01-01

Coarse and fine woody materials (CWD and FWD) are substantial forest ecosystem carbon (C) stocks. There is a lack of understanding how these detritus C stocks may respond to climate change. This study used a nation-wide inventory of CWD and FWD in the United States to examine how these C stocks vary by latitude. Results indicate that the highest CWD and FWD C stocks...

Emissions inventories and options for control. Summary report

Energy Technology Data Exchange (ETDEWEB)

Swart, R.J.; Van Amstel, A.R.; Van den Born, G.J.; Kroeze, C.

1995-10-01

This report is the final summary report of the project `Social causes of the greenhouse effect, emissions inventories and options for control`. The objectives of the project, that started in 1990, were to support the development of a comprehensive Dutch climate policy and to identify gaps in the knowledge about sources of greenhouse gases. The four phases of the project are summarized. In the first phase, a first national inventory of greenhouse gas emissions was made, capturing carbon dioxide (CO{sub 2}), chlorofluorocarbons (CFCs), methane (CH{sub 4}), nitrous oxide (N{sub 2}O) and the ozone precursors carbon monoxide (CO), nitrogen oxides (NO{sub x} ) and volatile organic compounds (VOC). In the second phase, the acquired expertise was used to support the development of Guidelines for National Emissions Inventories by the joint OECD/IPCC programme through workshop organization and participation in the international planning group. In the third phase, a detailed analysis was performed of the sources of methane, its current and future emissions and the options for control. Finally, a similar analysis was performed for nitrous oxide. In these studies, it was found that policies not specifically aiming at mitigating climate change, would help to control the emissions of the non-CO{sub 2} greenhouse gases. While for methane, national emissions would even decrease because of measures in the livestock management and waste disposal sectors, for nitrous oxide the reductions in agricultural emissions would be outweighed by increases, especially in the transportation sector. The project shows that the application of more detailed information leads to differences with the Guidelines, both because of the limited number of source categories in the Guidelines and because of different, locally specific emissions factors. 4 figs., 2 tabs., 14 refs.

EVALUATION OF THE MODERN TENDENCIES IN THE UKRAINIAN STOCK MARKET DEVELOPMENT

Directory of Open Access Journals (Sweden)

Oleksandr Trofimchuk

2015-11-01

Full Text Available The purpose of the article is to research and critically evaluate the features of functioning and development the stock market in Ukraine. The main point is to substantiate modern tendencies and to find ways of more efficient development of the Ukrainian stock market. Methodology. The research is based on the analysis of the important aspects which characterize stock market development. They are the volume of trading activity that was done on stock exchanges, level of market capitalization, economic concentration, price policy on market services, and control over the insider information use and manipulation identification. Results. On the basis of volume of trading activity that was done on stock exchanges, features of stock market structure are determined. Comparative analysis between the stock market capitalization level of Ukraine and average world index of stock market capitalization is done. The level and dynamic of economic concentration is defined. Features of competition between Ukrainian stock exchanges are analyzed. Great attention in research is paid to problems of control over the insider information use and principles of manipulation identification by stock exchanges. Value/originality. The research showed that main amount of trading operations was done in “shadow” stock market, capitalization level decreased and stock market in Ukraine does not meet international standards of transparency. Further research should be focused on problems of ensuring the effective implementation of the basic principles of competition between market participants. Main point is to provide law mechanisms to increase transparency level of the national stock market and to increase share of organized stock market in Ukraine.

Estimating agro-ecosystem carbon balance of northern Japan, and comparing the change in carbon stock by soil inventory and net biome productivity.

Science.gov (United States)

Li, Xi; Toma, Yo; Yeluripati, Jagadeesh; Iwasaki, Shinya; Bellingrath-Kimura, Sonoko D; Jones, Edward O; Hatano, Ryusuke

2016-06-01

Soil C sequestration in croplands is deemed to be one of the most promising greenhouse gas mitigation options for agriculture. We have used crop-level yields, modeled heterotrophic respiration (Rh) and land use data to estimate spatio-temporal changes in regional scale net primary productivity (NPP), plant C inputs, and net biome productivity (NBP) in northern Japan's arable croplands and grasslands for the period of 1959-2011. We compared the changes in C stocks derived from estimated NBP and using repeated inventory datasets for each individual land use type from 2005 to 2011. For the entire study region of 2193 ha, overall annual plant C inputs to the soil constituted 37% of total region NPP. Plant C inputs in upland areas (excluding bush/fallow) could be predicted by climate variables. Overall NBP for all land use types increased from -1.26MgCha(-1)yr(-1) in 1959-0.26 Mg Cha(-1)yr(-1) in 2011. However, upland and paddy fields showed a decreased in NBP over the period of 1959-2011, under the current C input scenario. From 1988, an increase in agricultural abandonment (bush/fallow) and grassland cover caused a slow increase in the regional C pools. The comparison of carbon budgets using the NBP estimation method and the soil inventory method indicated no significant difference between the two methods. Our results showed C loss in upland crops, paddy fields and sites that underwent land use change from paddy field to upland sites. We also show C gain in grassland from 2005 to 2011. An underestimation of NBP or an overestimation of repeated C inventories cannot be excluded, but either method may be suitable for tracking absolute changes in soil C, considering the uncertainty associated with these methods. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimal Inventory Policy under Permissible Payment Delay in Fashion Supply Chains

OpenAIRE

Guo Li; Yuchen Kang; Mengqi Liu; Zhaohua Wang

2014-01-01

This paper investigates a retailer’s optimal inventory cycle and the corresponding time of payment in fashion supply chains where a supplier allows the payment delay. Here according to the established model we first analyze the retailer's reaction, and then find out the retailer’s optimal inventory policy and time of payment to maximize its total profit. Our result shows that it is not always the best choice for retailers of fashion supply chains to choose the discount way to replenish stocks...

A new detailed map of total phosphorus stocks in Australian soil.

Science.gov (United States)

Viscarra Rossel, Raphael A; Bui, Elisabeth N

2016-01-15

Accurate data are needed to effectively monitor environmental condition, and develop sound policies to plan for the future. Globally, current estimates of soil total phosphorus (P) stocks are very uncertain because they are derived from sparse data, with large gaps over many areas of the Earth. Here, we derive spatially explicit estimates, and their uncertainty, of the distribution and stock of total P in Australian soil. Data from several sources were harmonized to produce the most comprehensive inventory of total P in soil of the continent. They were used to produce fine spatial resolution continental maps of total P in six depth layers by combining the bootstrap, a decision tree with piecewise regression on environmental variables and geostatistical modelling of residuals. Values of percent total P were predicted at the nodes of a 3-arcsecond (approximately 90 m) grid and mapped together with their uncertainties. We combined these predictions with those for bulk density and mapped the total soil P stock in the 0-30 cm layer over the whole of Australia. The average amount of P in Australian topsoil is estimated to be 0.98 t ha(-1) with 90% confidence limits of 0.2 and 4.2 t ha(-1). The total stock of P in the 0-30 cm layer of soil for the continent is 0.91 Gt with 90% confidence limits of 0.19 and 3.9 Gt. The estimates are the most reliable approximation of the stock of total P in Australian soil to date. They could help improve ecological models, guide the formulation of policy around food and water security, biodiversity and conservation, inform future sampling for inventory, guide the design of monitoring networks, and provide a benchmark against which to assess the impact of changes in land cover, land use and management and climate on soil P stocks and water quality in Australia. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

The Development of Plant Maintenance Scheduling Via lnventory System for Sustainable Plant Operation

Directory of Open Access Journals (Sweden)

Masripan Roslizan

2016-01-01

Full Text Available Industrial sector becomes the main concern for developing country. By the time, it was increased rapidly. However, there are many problems observed such as maintenance scheduling, stock inventory and supply chain. Therefore, this research develops new inventory system to develop sustainable plant operation with a high capability to plant operation especially to stock inventory of machine component. In also required green application with minimised used on paper. This system is developed using Radio Frequency Identification (RFID for inventory control which integrated with web-based system. This system consists of several modules such as station module, item module and item request module and report of critical stock in the store. This system can be controlled from a hand-phone with internet connection or automatic alert such as Short Massage Send (SMS and email. The developed system is very effective in monitoring the stock material through the barcode, supply chain and worker performance as well as to reduce the lead time for maintenance activities of the company through sustainable plant operation.

A Novel Mobile Personalized Recommended Method Based on Money Flow Model for Stock Exchange

Directory of Open Access Journals (Sweden)

Qingzhen Xu

2014-01-01

Full Text Available Personalized recommended method is widely used to recommend commodities for target customers in e-commerce sector. The core idea of merchandise personalized recommendation can be applied to financial field, which can also achieve stock personalized recommendation. This paper proposes a new recommended method using collaborative filtering based on user fuzzy clustering and predicts the trend of those stocks based on money flow. We use M/G/1 queue system with multiple vacations and server close-down time to measure practical money flow. Based on the indicated results of money flow, we can select the more valued stock to recommend to investors. The experimental results show that the proposed method provides investors with reliable practical investment guidance and receiving more returns.

Site classification of ponderosa pine stands under stocking control in California

Science.gov (United States)

Robert F. Powers; William W. Oliver

1978-01-01

Existing systems for estimating site index of ponderosa pine (Pinus ponderosa Laws.) do not apply well to California stands where stocking is controlled. A more suitable system has been developed using trends in natural height growth, derived from stem analysis of dominant trees in California. This site index system produces polymorphic patterns of...

Sustainable economic production quantity models for inventory systems with shortage

DEFF Research Database (Denmark)

Taleizadeh, Ata Allah; Soleymanfar, Vahid Reza; Govindan, Kannan

2018-01-01

optimal values of inventory system variables, we solve four independent profit maximization problems for four different situations. These proposed models include a basic model in which shortages are not allowed, and when shortages are allowed, the lost sale, full backordering and partial backordering...... (EPQ). The theoretical sustainable EOQ and EPQ models are basic models that ignore many real-life conditions such as the possibility of stock-out in inventory systems. In this paper, we develop four new sustainable economic production quantity models that consider different shortage situations. To find...

National inventories of down and dead woody material forest carbon stocks in the United States: Challenges and opportunities

Science.gov (United States)

C.W. Woodall; L.S. Heath; J.E. Smith

2008-01-01

Concerns over the effect of greenhouse gases and consequent international agreements and regional/national programs have spurred the need for comprehensive assessments of forest ecosystem carbon stocks. Down and dead woody (DDW) materials are a substantial component of forest carbon stocks; however, few surveys of DDW carbon stocks have been conducted at national-...

Assessment on the rates and potentials of soil organic carbon sequestration in agricultural lands in Japan using a process-based model and spatially explicit land-use change inventories - Part 1: Historical trend and validation based on nation-wide soil monitoring

Science.gov (United States)

Yagasaki, Y.; Shirato, Y.

2014-08-01

In order to estimate a country-scale soil organic carbon (SOC) stock change in agricultural lands in Japan, while taking into account the effect of land-use changes, climate, different agricultural activities and the nature of soils, a spatially explicit model simulation system was developed using Rothamsted Carbon Model (RothC) with an integration of spatial and temporal inventories. Simulation was run from 1970 to 2008 with historical inventories. Simulated SOC stock was compared with observations in a nation-wide stationary monitoring program conducted during 1979-1998. Historical land-use change, characterized by a large decline in the area of paddy fields as well as a small but continuous decline in the area of orchards, occurred along with a relatively large increase in upland crop fields, unmanaged grasslands, and settlements (i.e. conversion of agricultural fields due to urbanization or abandoning). Results of the simulation on SOC stock change under varying land-use change indicated that land-use conversion from agricultural fields to settlements or other lands, as well as that from paddy fields to croplands have likely been an increasing source of CO2 emission, due to the reduction of organic carbon input to soils and the enhancement of SOC decomposition through transition of soil environment from anaerobic to aerobic conditions. The area-weighted mean concentrations of the simulated SOC stocks calculated for major soil groups under paddy fields and upland crop fields were comparable to those observed in the monitoring. Whereas in orchards, the simulated SOC stocks were underestimated. As the results of simulation indicated that SOC stock change under managed grasslands and settlements has been likely a major sink and source of CO2 emission at country-scale, respectively, validation of SOC stock change under these land-use types, which could not have been accomplished due to limited availability or a lack of measurement, remains a forthcoming challenge.

Stock prices forecasting based on wavelet neural networks with PSO

OpenAIRE

Wang Kai-Cheng; Yang Chi-I; Chang Kuei-Fang

2017-01-01

This research examines the forecasting performance of wavelet neural network (WNN) model using published stock data obtained from Financial Times Stock Exchange (FTSE) Taiwan Stock Exchange (TWSE) 50 index, also known as Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX), hereinafter referred to as Taiwan 50. Our WNN model uses particle swarm optimization (PSO) to choose the appropriate initial network values for different companies. The findings come with two advantages. First...

A joint inventory policy under permissible delay in payment and stochastic demand (Case study: Pharmacy Department of Pariaman Hospital)

Science.gov (United States)

Jonrinaldi, Primadi, M. Yugo; Hadiguna, Rika Ampuh

2017-11-01

Inventory cannot be avoided by organizations. One of them is a hospital which has a functional unit to manage the drugs and other medical supplies such as disposable and laboratory material. The unit is called Pharmacy Department which is responsible to do all of pharmacy services in the hospital. The current problem in Pharmacy Department is that the level of drugs and medical supplies inventory is too high. Inventory is needed to keep the service level to customers but at the same time it increases the cost of holding the items, so there should be a policy to keep the inventory on an optimal condition. To solve such problem, this paper proposes an inventory policy in Pharmacy Department of Pariaman Hospital. The inventory policy is determined by using Economic Order Quantity (EOQ) model under condition of permissible delay in payment for multiple products considering safety stock to anticipate stochastic demand. This policy is developed based on the actual condition of the system studied where suppliers provided a certain period to Pharmacy Department to complete the payment of the order. Based on implementation using software Lingo 13.0, total inventory cost of proposed policy of IDR 137,334,815.34 is 37.4% lower than the total inventory cost of current policy of IDR 219,511,519.45. Therefore, the proposed inventory policy is applicable to the system to minimize the total inventory cost.

Multiscale sample entropy and cross-sample entropy based on symbolic representation and similarity of stock markets

Science.gov (United States)

Wu, Yue; Shang, Pengjian; Li, Yilong

2018-03-01

A modified multiscale sample entropy measure based on symbolic representation and similarity (MSEBSS) is proposed in this paper to research the complexity of stock markets. The modified algorithm reduces the probability of inducing undefined entropies and is confirmed to be robust to strong noise. Considering the validity and accuracy, MSEBSS is more reliable than Multiscale entropy (MSE) for time series mingled with much noise like financial time series. We apply MSEBSS to financial markets and results show American stock markets have the lowest complexity compared with European and Asian markets. There are exceptions to the regularity that stock markets show a decreasing complexity over the time scale, indicating a periodicity at certain scales. Based on MSEBSS, we introduce the modified multiscale cross-sample entropy measure based on symbolic representation and similarity (MCSEBSS) to consider the degree of the asynchrony between distinct time series. Stock markets from the same area have higher synchrony than those from different areas. And for stock markets having relative high synchrony, the entropy values will decrease with the increasing scale factor. While for stock markets having high asynchrony, the entropy values will not decrease with the increasing scale factor sometimes they tend to increase. So both MSEBSS and MCSEBSS are able to distinguish stock markets of different areas, and they are more helpful if used together for studying other features of financial time series.

Dynamic UAV-based traffic monitoring under uncertainty as a stochastic arc-inventory routing policy

Directory of Open Access Journals (Sweden)

Joseph Y.J. Chow

2016-10-01

Full Text Available Given the rapid advances in unmanned aerial vehicles, or drones, and increasing need to monitor at a city level, one of the current research gaps is how to systematically deploy drones over multiple periods. We propose a real-time data-driven approach: we formulate the first deterministic arc-inventory routing problem and derive its stochastic dynamic policy. The policy is expected to be of greatest value in scenarios where uncertainty is highest and costliest, such as city monitoring during major events. The Bellman equation for an approximation of the proposed inventory routing policy is formulated as a selective vehicle routing problem. We propose an approximate dynamic programming algorithm based on Least Squares Monte Carlo simulation to find that policy. The algorithm has been modified so that the least squares dependent variable is defined to be the “expected stock out cost upon the next replenishment”. The new algorithm is tested on 30 simulated instances of real time trajectories over 5 time periods of the selective vehicle routing problem to evaluate the proposed policy and algorithm. Computational results on the selected instances show that the algorithm on average outperforms the myopic policy by 23–28%, depending on the parametric design. Further tests are conducted on classic benchmark arc routing problem instances. The 11-link instance gdb19 (Golden et al., 1983 is expanded into a sequential 15-period stochastic dynamic example and used to demonstrate why a naïve static multi-period deployment plan would not be effective in real networks.

Optimal lateral transshipment policy for a two location inventory problem

NARCIS (Netherlands)

Wijk, van A.C.C.; Adan, I.J.B.F.; Houtum, van G.J.J.A.N.

2009-01-01

We consider an inventory model for spare parts with two stockpoints, providing repairable parts for a critical component of advanced technical systems. As downtime costs for these systems are huge, ready-for-use spare parts are kept on stock, to be able to quickly respond to a breakdown of a system.

Expected value analysis for integrated supplier selection and inventory control of multi-product inventory system with fuzzy cost

Science.gov (United States)

Sutrisno, Widowati, Tjahjana, R. Heru

2017-12-01

The future cost in many industrial problem is obviously uncertain. Then a mathematical analysis for a problem with uncertain cost is needed. In this article, we deals with the fuzzy expected value analysis to solve an integrated supplier selection and supplier selection problem with uncertain cost where the costs uncertainty is approached by a fuzzy variable. We formulate the mathematical model of the problems fuzzy expected value based quadratic optimization with total cost objective function and solve it by using expected value based fuzzy programming. From the numerical examples result performed by the authors, the supplier selection problem was solved i.e. the optimal supplier was selected for each time period where the optimal product volume of all product that should be purchased from each supplier for each time period was determined and the product stock level was controlled as decided by the authors i.e. it was followed the given reference level.

Static and dynamic factors in an information-based multi-asset artificial stock market

Science.gov (United States)

Ponta, Linda; Pastore, Stefano; Cincotti, Silvano

2018-02-01

An information-based multi-asset artificial stock market characterized by different types of stocks and populated by heterogeneous agents is presented. In the market, agents trade risky assets in exchange for cash. Beside the amount of cash and of stocks owned, each agent is characterized by sentiments and agents share their sentiments by means of interactions that are determined by sparsely connected networks. A central market maker (clearing house mechanism) determines the price processes for each stock at the intersection of the demand and the supply curves. Single stock price processes exhibit volatility clustering and fat-tailed distribution of returns whereas multivariate price process exhibits both static and dynamic stylized facts, i.e., the presence of static factors and common trends. Static factors are studied making reference to the cross-correlation of returns of different stocks. The common trends are investigated considering the variance-covariance matrix of prices. Results point out that the probability distribution of eigenvalues of the cross-correlation matrix of returns shows the presence of sectors, similar to those observed on real empirical data. As regarding the dynamic factors, the variance-covariance matrix of prices point out a limited number of assets prices series that are independent integrated processes, in close agreement with the empirical evidence of asset price time series of real stock markets. These results remarks the crucial dependence of statistical properties of multi-assets stock market on the agents' interaction structure.

Novel acyloxy derivatives of branched mono- and polyol esters of sal fat: multiviscosity grade lubricant base stocks.

Science.gov (United States)

Kamalakar, Kotte; Sai Manoj, Gorantla N V T; Prasad, Rachapudi B N; Karuna, Mallampalli S L

2014-12-10

Sal fat, a nontraditional seed oil, was chemically modified to obtain base stocks with a wide range of specifications that can replace mineral oil base stocks. Sal fatty acids were enriched to 72.6% unsaturation using urea adduct method and reacted with branched mono alcohol, 2-ethylhexanol (2-EtH), and polyols namely neopentyl glycol (NPG) and trimethylolpropane (TMP) to obtain corresponding esters. The esters were hydroxylated and then acylated using propionic, butyric, and hexanoic anhydrides to obtain corresponding acylated derivatives. The acylated TMP esters exhibited very high viscosities (427.35-471.93 cSt at 40 °C) similar to those of BS 150 mineral oil base stock range, ISO VG 460, while the acylated NPG esters (268.81-318.84 cSt at 40 °C) and 2-EtH esters viscosities (20.94-24.44 cSt at 40 °C) exhibited viscosities in the range of ISO VG 320 and 22 respectively with good viscosity indices. Acylated NPG esters were found suitable for high temperature and acylated 2-ethylhexyl esters for low viscosity grade industrial applications. It was observed that the thermo-oxidative stabilities of all acylated products were found better compared to other vegetable oil based base stocks. Overall, all the sal fat based lubricant base stocks are promising candidates with a wide range of properties, which can replace most of the mineral oil base stocks with appropriate formulations.

Using an experimental manipulation to determine the effectiveness of a stock enhancement program

Science.gov (United States)

Stewart, David R.; Long, James M.

2015-01-01

We used an experimental manipulation to determine the impact of stocking 178 mm channel catfish Ictalurus punctatus in six impoundments. The study design consisted of equal numbers (two) of control, ceased-stock, and stocked treatments that were sampled one year before and two years after stocking. Relative abundance, growth, size structure, and average weight significantly changed over time based on samples collected with hoop nets. Catch rates decreased at both ceased-stock lakes and increased for one stocked lake, while growth rates changed for at least one ceased-stock and stocked lake. The average weight of channel catfish in the ceased-stock treatment increased by 6% and 25%, whereas weight decreased by 28% and 78% in both stocked lakes. The variability in observed responses between lakes in both ceased-stock and stocked treatments indicates that a one-size-fits-all stocking agenda is impractical, suggesting lake specific and density-dependent mechanisms affect channel catfish population dynamics.

The Effects of Variability in Demand and Time Parameters for Multi-Item, Multi-Echelon, Multi-Indenture Reparable Inventory Systems

Science.gov (United States)

2002-03-26

and Scheduling. New York: John Wiley & Sons, 1998. 91 Vita Captain Roberto Carlos Borges de Abreu was born on 31 July 1965 in Bom Jesus ...services, inventory management is also of great importance. “Imagine a hospital stocking out of blood, or the air force stocking out of a mission

Linking plant functional traits and forest carbon stocks in the Congo Basin

Science.gov (United States)

Kearsley, Elizabeth; Verbeeck, Hans; Hufkens, Koen; Lewis, Simon; Huygens, Dries; Beeckman, Hans; Steppe, Kathy; Boeckx, Pascal

2013-04-01

Accurate estimates of the amount of carbon stored in tropical forests represent crucial baseline data for recent climate change mitigation policies. Such data are needed to quantify possible emissions due to deforestation and forest degradation, and to evaluate the potential of these forests to act as carbon sinks. Currently, only rough estimates of the carbon stocks for Central African tropical forests are available due to a lack of field data, and little is known about the response of these stocks to climate change. We present the first ground-based carbon stock data for the central Congo Basin in Yangambi, D. R. Congo, based on data of 20 inventory plots of 1 ha covering different forest types. We found an average aboveground carbon stock of 163 ± 19 Mg C ha-1 for intact old-growth forest, which is significantly lower than the stocks recorded in the outer regions of the Congo Basin. Commonly studied drivers for variations of carbon stocks include climatic and edaphic factors, but detailed trait-based studies are lacking. We identified a significant difference in height-diameter relations across the Congo Basin as a driver for spatial differences in carbon stocks. The study of a more detailed interaction of the environment and the available tree species pool as drivers for differences in carbon storage could have large implications. The effect of the species pool on carbon storage can be large since species differ in their ability to sequester carbon, and the collective functional characteristics of plant communities could be a major driver of carbon accumulation. The use of a trait-based approach shows high potential for identifying and quantifying carbon stocks as an ecosystem service. We test for associations between functional trait values and carbon storage across multiple regrowth and old-growth forests types in the Yangambi study area, with soil properties and climate similar for all plots. A selection of traits associated with carbon dynamics is made

Carbon stock and carbon turnover in boreal and temperate forests - Integration of remote sensing data and global vegetation models

Science.gov (United States)

Thurner, Martin; Beer, Christian; Carvalhais, Nuno; Forkel, Matthias; Tito Rademacher, Tim; Santoro, Maurizio; Tum, Markus; Schmullius, Christiane

2016-04-01

Long-term vegetation dynamics are one of the key uncertainties of the carbon cycle. There are large differences in simulated vegetation carbon stocks and fluxes including productivity, respiration and carbon turnover between global vegetation models. Especially the implementation of climate-related mortality processes, for instance drought, fire, frost or insect effects, is often lacking or insufficient in current models and their importance at global scale is highly uncertain. These shortcomings have been due to the lack of spatially extensive information on vegetation carbon stocks, which cannot be provided by inventory data alone. Instead, we recently have been able to estimate northern boreal and temperate forest carbon stocks based on radar remote sensing data. Our spatially explicit product (0.01° resolution) shows strong agreement to inventory-based estimates at a regional scale and allows for a spatial evaluation of carbon stocks and dynamics simulated by global vegetation models. By combining this state-of-the-art biomass product and NPP datasets originating from remote sensing, we are able to study the relation between carbon turnover rate and a set of climate indices in northern boreal and temperate forests along spatial gradients. We observe an increasing turnover rate with colder winter temperatures and longer winters in boreal forests, suggesting frost damage and the trade-off between frost adaptation and growth being important mortality processes in this ecosystem. In contrast, turnover rate increases with climatic conditions favouring drought and insect outbreaks in temperate forests. Investigated global vegetation models from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT, are able to reproduce observation-based spatial climate - turnover rate relationships only to a limited extent. While most of the models compare relatively well in terms of NPP, simulated

Dataset for petroleum based stock markets and GAUSS codes for SAMEM

Directory of Open Access Journals (Sweden)

Ahmed A.A. Khalifa

2017-02-01

Full Text Available This article includes a unique data set of a balanced daily (Monday, Tuesday and Wednesday for oil and natural gas volatility and the oil rich economies’ stock markets for Saudi Arabia, Qatar, Kuwait, Abu Dhabi, Dubai, Bahrain and Oman, using daily data over the period spanning Oct. 18, 2006–July 30, 2015. Additionally, we have included unique GAUSS codes for estimating the spillover asymmetric multiplicative error model (SAMEM with application to Petroleum-Based Stock Market. The data, the model and the codes have many applications in business and social science.

Dataset for petroleum based stock markets and GAUSS codes for SAMEM.

Science.gov (United States)

Khalifa, Ahmed A A; Bertuccelli, Pietro; Otranto, Edoardo

2017-02-01

This article includes a unique data set of a balanced daily (Monday, Tuesday and Wednesday) for oil and natural gas volatility and the oil rich economies' stock markets for Saudi Arabia, Qatar, Kuwait, Abu Dhabi, Dubai, Bahrain and Oman, using daily data over the period spanning Oct. 18, 2006-July 30, 2015. Additionally, we have included unique GAUSS codes for estimating the spillover asymmetric multiplicative error model (SAMEM) with application to Petroleum-Based Stock Market. The data, the model and the codes have many applications in business and social science.

Stock or stroke? Stock market movement and stroke incidence in Taiwan.

Science.gov (United States)

Chen, Chun-Chih; Chen, Chin-Shyan; Liu, Tsai-Ching; Lin, Ying-Tzu

2012-12-01

This paper investigates the impact of stock market movement on incidences of stroke utilizing population-based aggregate data in Taiwan. Using the daily data from the Taiwan Stock Exchange Capitalization Weighted Stock Index and from the National Health Insurance Research Database during 2001/1/1-2007/12/31, which consist of 2556 observations, we examine the effects of stock market on stroke incidence - the level effect and the daily change effects. In general, we find that both a low stock index level and a daily fall in the stock index are associated with greater incidences of stroke. We further partition the data on sex and age. The level effect is found to be significant for either gender, in the 45-64 and 65 ≥ age groups. In addition, two daily change effects are found to be significant for males and the elderly. Although stockholdings can increase wealth, they can also increase stroke incidence, thereby representing a cost to health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Solving Inventory Routing Problems Using Location Based Heuristics

Directory of Open Access Journals (Sweden)

Paweł Hanczar

2014-01-01

Full Text Available Inventory routing problems (IRPs occur where vendor managed inventory replenishment strategies are implemented in supply chains. These problems are characterized by the presence of both transportation and inventory considerations, either as parameters or constraints. The research presented in this paper aims at extending IRP formulation developed on the basis of location based heuristics proposed by Bramel and Simchi-Levi and continued by Hanczar. In the first phase of proposed algorithms, mixed integer programming is used to determine the partitioning of customers as well as dates and quantities of deliveries. Then, using 2-opt algorithm for solving the traveling sales-person problem the optimal routes for each partition are determined. In the main part of research the classical formulation is extended by additional constraints (visit spacing, vehicle filling rate, driver (vehicle consistency, and heterogeneous fleet of vehicles as well as the additional criteria are discussed. Then the impact of using each of proposed extensions for solution possibilities is evaluated. The results of computational tests are presented and discussed. Obtained results allow to conclude that the location based heuristics should be considered when solving real life instances of IRP. (original abstract

Mirage: Mitigating Illicit Inventorying in a RFID Enabled Retail Environment

OpenAIRE

White, Jonathan; Banerjee, Nilanjan

2010-01-01

Given its low dollar and maintenance cost, RFID is poised to become the enabling technology for inventory control and supply chain management. However, as an outcome of its low cost, RFID based inventory control is susceptible to pernicious security and privacy threats. A deleterious attack on such a system is corporate espionage, where attackers through illicit inventorying infer sales and restocking trends for products. In this paper, we first present plausible aftermaths of corporate espio...

Creating a Global Building Inventory for Earthquake Loss Assessment and Risk Management

Science.gov (United States)

Jaiswal, Kishor; Wald, David J.

2008-01-01

Earthquakes have claimed approximately 8 million lives over the last 2,000 years (Dunbar, Lockridge and others, 1992) and fatality rates are likely to continue to rise with increased population and urbanizations of global settlements especially in developing countries. More than 75% of earthquake-related human casualties are caused by the collapse of buildings or structures (Coburn and Spence, 2002). It is disheartening to note that large fractions of the world's population still reside in informal, poorly-constructed & non-engineered dwellings which have high susceptibility to collapse during earthquakes. Moreover, with increasing urbanization half of world's population now lives in urban areas (United Nations, 2001), and half of these urban centers are located in earthquake-prone regions (Bilham, 2004). The poor performance of most building stocks during earthquakes remains a primary societal concern. However, despite this dark history and bleaker future trends, there are no comprehensive global building inventories of sufficient quality and coverage to adequately address and characterize future earthquake losses. Such an inventory is vital both for earthquake loss mitigation and for earthquake disaster response purposes. While the latter purpose is the motivation of this work, we hope that the global building inventory database described herein will find widespread use for other mitigation efforts as well. For a real-time earthquake impact alert system, such as U.S. Geological Survey's (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER), (Wald, Earle and others, 2006), we seek to rapidly evaluate potential casualties associated with earthquake ground shaking for any region of the world. The casualty estimation is based primarily on (1) rapid estimation of the ground shaking hazard, (2) aggregating the population exposure within different building types, and (3) estimating the casualties from the collapse of vulnerable buildings. Thus, the

A computer program for controlling a university radioactive material inventory: From confusion to computer to control

International Nuclear Information System (INIS)

Robb, D.B.; Riches, C.G.; O'Brian, M.J.; Riordan, F.J.

1984-01-01

The University of Washington is a large user of radioactive material. Over 250 authorized programs are working in over 600 labs with nearly 3500 orders of radioactive material per year. The state license sets limits on the total amount of material on campus. There are also limits on sewer disposal. To meet these needs it is necessary to know the amount of material on campus at any time. A computer program was developed which covered many aspects of the radiation safety record needs including inventory control. Inventory is now managed by tracking each order from purchase to disposal. A screen menu as part of the interactive program allows immediate and detailed information about the inventory at time of purchase approval and delivery. Because of this system our knowledge and control of radionuclide work on campus has increased dramatically. A description of how this system is used during ordering, delivery and disposal will be given. Details on the methods to check limits are included along with a summary of the reports made possible by the current data files

Effect of tree species on carbon stocks in forest floor and mineral soil and implications for soil carbon inventories

NARCIS (Netherlands)

Schulp, C.J.E.; Nabuurs, G.J.; Verburg, P.H.; Waal, de R.W.

2008-01-01

Forest soil organic carbon (SOC) and forest floor carbon (FFC) stocks are highly variable. The sampling effort required to assess SOC and FFC stocks is therefore large, resulting in limited sampling and poor estimates of the size, spatial distribution, and changes in SOC and FFC stocks in many

Towards an Integrated Assessment Model for Tropospheric Ozone-Emission Inventories, Scenarios and Emission-control Options

OpenAIRE

Olsthoorn, X.

1994-01-01

IIASA intends to extend its RAINS model for addressing the issue of transboundary ozone air pollution. This requires the development of a VOC-emissions module, VOCs being precursors in ozone formation. The module should contain a Europe-wide emission inventory, a submodule for developing emission scenarios and a database of measures for VOC-emission control, including data about control effectiveness and control costs. It is recommended to use the forthcoming CORINAIR90 inventory for construc...

Optimization in Fuzzy Economic Order Quantity (FEOQ) Model with Deteriorating Inventory and Units Lost

OpenAIRE

Monalisha Pattnaik

2014-01-01

Background: This model presents the effect of deteriorating items in fuzzy optimal instantaneous replenishment for finite planning horizon. Accounting for holding cost per unit per unit time and ordering cost per order have traditionally been the case of modeling inventory systems in fuzzy environment. These imprecise parameters defined on a bounded interval on the axis of real numbers and the physical characteristics of stocked items dictate the nature of inventory policies implemented ...

Tower taxes or higher executive bonuses: How inventory valuation choices best exhibit us corporate governance failings

Directory of Open Access Journals (Sweden)

Kevin A. Diehl

2012-06-01

Full Text Available This research seeks to update and finally determine for the Fortune 500 whether the market values the inventory valuation choice of last-in, first-out (LIFO over first-in, first-out (FIFO as some signal of reporting and management quality. The market can adjust LIFO earnings to FIFO earnings. Thus, the only issue then is that companies choosing FIFO pay higher taxes, which shareowners should disfavor. Indeed, only 20 percent of the Fortune 500 utilize LIFO to value any inventory. However, after Spearman correlations and logistic regression, the research statistically significantly shows that investors are willing to give premiums on the price of stock for the choice of LIFO. Thus, companies should choose LIFO to reduce taxes and increase their stock prices.

32 CFR 169a.8 - Inventory and review schedule (Report Control Symbol DD-P&L(A)).

Science.gov (United States)

2010-07-01

... 32 National Defense 1 2010-07-01 2010-07-01 false Inventory and review schedule (Report Control... OF DEFENSE DEFENSE CONTRACTING COMMERCIAL ACTIVITIES PROGRAM PROCEDURES Procedures § 169a.8 Inventory and review schedule (Report Control Symbol DD-P&L(A)). (a) Information in each DoD Component's...

Using combinatorial problem decomposition for optimizing plutonium inventory management

International Nuclear Information System (INIS)

Niquil, Y.; Gondran, M.; Voskanian, A.; Paris-11 Univ., 91 - Orsay

1997-03-01

Plutonium Inventory Management Optimization can be modeled as a very large 0-1 linear program. To solve it, problem decomposition is necessary, since other classic techniques are not efficient for such a size. The first decomposition consists in favoring constraints that are the most difficult to reach and variables that have the highest influence on the cost: fortunately, both correspond to stock output decisions. The second decomposition consists in mixing continuous linear program solving and integer linear program solving. Besides, the first decisions to be taken are systematically favored, for they are based on data considered to be sure, when data supporting later decisions in known with less accuracy and confidence. (author)

Using combinatorial problem decomposition for optimizing plutonium inventory management

Energy Technology Data Exchange (ETDEWEB)

Niquil, Y.; Gondran, M. [Electricite de France (EDF), 92 - Clamart (France). Direction des Etudes et Recherches; Voskanian, A. [Electricite de France (EDF), 92 - Clamart (France). Direction des Etudes et Recherches]|[Paris-11 Univ., 91 - Orsay (France). Lab. de Recherche en Informatique

1997-03-01

Plutonium Inventory Management Optimization can be modeled as a very large 0-1 linear program. To solve it, problem decomposition is necessary, since other classic techniques are not efficient for such a size. The first decomposition consists in favoring constraints that are the most difficult to reach and variables that have the highest influence on the cost: fortunately, both correspond to stock output decisions. The second decomposition consists in mixing continuous linear program solving and integer linear program solving. Besides, the first decisions to be taken are systematically favored, for they are based on data considered to be sure, when data supporting later decisions in known with less accuracy and confidence. (author) 7 refs.

Deploying an NFC-based inventory system: a case study

OpenAIRE

Poullie, Patrick; Bocek, Thomas; Stiller, Burkhard

2015-01-01

NFC tags and transceivers are ubiquitous and well supported. Like many academic research groups, the Communication Systems Group CSG of the University of Zürich owns many physical devices, which are required for research and teaching. Traditionally, a printed, human-readable inventory and attached labels have been used to keep track of these devices. A new inventory approach was developed with the aim of simplifying the data acquisition using an NFC tag-based system supported by an Android ap...

National inventory of radioactive wastes and valorizable materials. Synthesis report; Inventaire national des dechets radioactifs et des matieres valorisables. Rapport de synthese

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

This national inventory of radioactive wastes is a reference document for professionals and scientists of the nuclear domain and also for any citizen interested in the management of radioactive wastes. It contains: 1 - general introduction; 2 - the radioactive wastes: definition, classification, origin and management; 3 - methodology of the inventory: organization, accounting, prospective, production forecasting, recording of valorizable materials, exhaustiveness, verification tools; 4 - general results: radioactive waste stocks recorded until December 31, 2002, forecasts for the 2003-2020 era, post-2020 prospects: dismantling operations, recording of valorizable materials; 5 - inventory per producer or owner: front-end fuel cycle facilities, power generation nuclear centers, back-end fuel cycle facilities, waste processing or maintenance facilities, civil CEA research centers, non-CEA research centers, medical activities (diagnostics, therapeutics, analyses), various industrial activities (sources fabrication, control, particular devices), military research and experiment centers, storage and disposal facilities; 6 - elements about radioactive polluted sites; 7 - examples of foreign inventories; 8 - conclusion and appendixes. (J.S.)

Inventory management of spare parts in an energy company

Energy Technology Data Exchange (ETDEWEB)

Guajardo, Mario; Roennqvist, Mikael; Halvorsen, Ann Mari; Kallevik, Svein Inge

2012-06-15

We address a problem of inventory management of spare parts in the context of a large energy company, producer of oil and gas. Spare parts are critical for assuring operational conditions in offshore platforms. About 200,000 different items are held in several inventory plants. The inventory system implemented at the company corresponds to a min-max system. The control parameters are decided based mainly on the expert judgment of the planners. Also, though the inventory plants can in practice be supplied from each other, the inventory planning is performed separately by the plant planners. This is because of different ownership structures where the studied company has the operative responsibility. The company is pursuing a system in which all planners conform to the same inventory management approach and evaluation, as well as being more cost efficient. Our work focuses on supporting this goal. We apply methods to decide the inventory control parameters for this system under a service level constraint. The methodology we use distinguishes unit-size and lot-size demand cases. We perform computational experiments to find control parameters for a sample of items. After the control parameters are found, we use them to explore the impact of risk pooling among the plants and inaccuracy arising from duplicate item codes.(Author)

Modeling and Computing of Stock Index Forecasting Based on Neural Network and Markov Chain

Science.gov (United States)

Dai, Yonghui; Han, Dongmei; Dai, Weihui

2014-01-01

The stock index reflects the fluctuation of the stock market. For a long time, there have been a lot of researches on the forecast of stock index. However, the traditional method is limited to achieving an ideal precision in the dynamic market due to the influences of many factors such as the economic situation, policy changes, and emergency events. Therefore, the approach based on adaptive modeling and conditional probability transfer causes the new attention of researchers. This paper presents a new forecast method by the combination of improved back-propagation (BP) neural network and Markov chain, as well as its modeling and computing technology. This method includes initial forecasting by improved BP neural network, division of Markov state region, computing of the state transition probability matrix, and the prediction adjustment. Results of the empirical study show that this method can achieve high accuracy in the stock index prediction, and it could provide a good reference for the investment in stock market. PMID:24782659

Modeling and Computing of Stock Index Forecasting Based on Neural Network and Markov Chain

Directory of Open Access Journals (Sweden)

Yonghui Dai

2014-01-01

Full Text Available The stock index reflects the fluctuation of the stock market. For a long time, there have been a lot of researches on the forecast of stock index. However, the traditional method is limited to achieving an ideal precision in the dynamic market due to the influences of many factors such as the economic situation, policy changes, and emergency events. Therefore, the approach based on adaptive modeling and conditional probability transfer causes the new attention of researchers. This paper presents a new forecast method by the combination of improved back-propagation (BP neural network and Markov chain, as well as its modeling and computing technology. This method includes initial forecasting by improved BP neural network, division of Markov state region, computing of the state transition probability matrix, and the prediction adjustment. Results of the empirical study show that this method can achieve high accuracy in the stock index prediction, and it could provide a good reference for the investment in stock market.

Analysis of inventory difference using fuzzy controllers

International Nuclear Information System (INIS)

Zardecki, A.

1994-01-01

The principal objectives of an accounting system for safeguarding nuclear materials are as follows: (a) to provide assurance that all material quantities are present in the correct amount; (b) to provide timely detection of material loss; and (c) to estimate the amount of any loss and its location. In fuzzy control, expert knowledge is encoded in the form of fuzzy rules, which describe recommended actions for different classes of situations represented by fuzzy sets. The concept of a fuzzy controller is applied to the forecasting problem in a time series, specifically, to forecasting and detecting anomalies in inventory differences. This paper reviews the basic notion underlying the fuzzy control systems and provides examples of application. The well-known material-unaccounted-for diffusion plant data of Jaech are analyzed using both feedforward neural networks and fuzzy controllers. By forming a deference between the forecasted and observed signals, an efficient method to detect small signals in background noise is implemented

Influence of Economic Value and Fundamental Analysis Toward Stock Market (Studies on the Retail Trade Industry Sector)

OpenAIRE

Widyatmini, Widyatmini; Damanik, Michael Valentino

2009-01-01

The objective of this research is to measure the influence of economics value added and fundamental analysis toward stock price on retail industry. Data which was deployed on this research are company financial report and stock price. Further, data was analyzed using regression method by deploying SPSS software. Research result shows that all independent variables proposed (economics value added, current ratio, quick ratio, total asset turnover ratio, inventory turnover ratio, gross profit ma...

Bounding Radionuclide Inventory and Accident Consequence Calculation for the 1L Target

International Nuclear Information System (INIS)

Kelsey, Charles T. IV

2011-01-01

A bounding radionuclide inventory for the tungsten of the Los Alamos Neutron Science Center (LANSCE) IL Target is calculated. Based on the bounding inventory, the dose resulting from the maximum credible incident (MCI) is calculated for the maximally exposed offsite individual (MEOl). The design basis accident involves tungsten target oxidation following a loss of cooling accident. Also calculated for the bounding radionuclide inventory is the ratio to the LANSCE inventory threshold for purposes of inventory control as described in the target inventory control policy. A bounding radionuclide inventory calculation for the lL Target was completed using the MCNPX and CINDER'90 codes. Continuous beam delivery at 200 (micro)A to 2500 mA·h was assumed. The total calculated activity following this irradiation period is 205,000 Ci. The dose to the MEOI from the MCI is 213 mrem for the bounding inventory. The LANSCE inventory control threshold ratio is 132.

Carbon stock and plants biodiversity of pekarangan in Cisadane watershed West Java

Science.gov (United States)

Aisyah Filqisthi, Tatag; Leonardus Kaswanto, Regan

2017-01-01

The presence of vegetation in Pekarangan can be proposed to mitigate global climate change impacts by CO2 sequestration and at the same time to promote the availability of food for the community. The aims of this research is to calculate carbon stock and biodiversity in pekarangan, and to compare carbon stock and biodiversity on three levels of Cisadane Watershed. Four groups of Pekarangan defined on a purposive random sampling. Allometric models were developed to estimate aboveground biomass of vegetation, and an inventory was conducted in 48 pekarangan. Shannon Weiner Index (H’) and Margalef Index (Dm) are used to evaluate biodiversity, averaged 2,84 and 5,10 (G1); 2,55 and 4,27 (G2); 2,56 and 4,52 (G3); 2,68 and 4,84 (G4), while carbon stock averaged 33,20 Mg Carbon/ha (G1); 29,97 Mg/ha (G2); 59,18 Mg/ha (G3); and 40,98 Mg/ha (G4). There is no relationship between biodiversity with carbon stock on pekarangan (R2 = 0,02), or tree’s biodiversity with carbon stock (R2 = 0,23). High resolution satellite imagery can be used to extrapolate carbon stock and plants biodiversity of Pekarangan at watershed level.

A New Decision-Making Method for Stock Portfolio Selection Based on Computing with Linguistic Assessment

Directory of Open Access Journals (Sweden)

Chen-Tung Chen

2009-01-01

Full Text Available The purpose of stock portfolio selection is how to allocate the capital to a large number of stocks in order to bring a most profitable return for investors. In most of past literatures, experts considered the portfolio of selection problem only based on past crisp or quantitative data. However, many qualitative and quantitative factors will influence the stock portfolio selection in real investment situation. It is very important for experts or decision-makers to use their experience or knowledge to predict the performance of each stock and make a stock portfolio. Because of the knowledge, experience, and background of each expert are different and vague, different types of 2-tuple linguistic variable are suitable used to express experts' opinions for the performance evaluation of each stock with respect to criteria. According to the linguistic evaluations of experts, the linguistic TOPSIS and linguistic ELECTRE methods are combined to present a new decision-making method for dealing with stock selection problems in this paper. Once the investment set has been determined, the risk preferences of investor are considered to calculate the investment ratio of each stock in the investment set. Finally, an example is implemented to demonstrate the practicability of the proposed method.

Multi-echelon, multi-indenture spare parts inventory control subject to system availability and budget constraints

International Nuclear Information System (INIS)

Costantino, Francesco; Di Gravio, Giulio; Tronci, Massimo

2013-01-01

Inventory management of spare parts is one of the most critical issues in the aeronautical industry, given the required level of system availability related to the strategic importance and high stocking costs of the components. Even if a large number of spare parts increases warehousing costs, every single shortage have a greater impact: the adoption of best-in-class inventory management techniques becomes crucial. On these considerations, the paper presents an innovative model of spare parts allocation for the Italian Air Force with the aim of minimizing backorders and, at the same time, ensuring an availability of 99% depending on the actual flight plan. The model, solved by a marginal analysis, considers an original configuration of features combining different skills of maintenance centers in a hierarchical multi-echelon, multi-item, multi-indenture structure. A real case is provided in order to analyze the solving method and the results. -- Highlights: •We studied a problem of allocations for spare parts of aeronautical systems. •The model presents different repair capabilities of maintenance centers. •The model fits constraints on budget and on total operational availability. •The model is solved by a marginal analysis with a backorder/price ratio. •A numerical example shows a spare parts allocation with relative considerations

Inverted edge effects on carbon stocks in human-dominated landscapes

Science.gov (United States)

Romitelli, I.; Keller, M.; Vieira, S. A.; Metzger, J. P.; Reverberi Tambosi, L.

2017-12-01

Although the importance of tropical forests to regulate greenhouse gases is well documented, little is known about what factors affect the ability of these forests to store carbon in human-dominated landscapes. Among those factors, the landscape structure, particularly the amount of forest cover, the type of matrix and edge effects, can have important roles. We tested how carbon stock is influenced by a combination of factors of landscape composition (pasture and forest cover), landscape configuration (edge effect) and relief factors (slope, elevation and aspect). To test those relationships, we performed a robust carbon stock estimation with inventory and LiDAR data in human-dominated landscapes from the Brazilian Atlantic forest region. The study area showed carbon stock mean 45.49 ± 9.34 Mg ha-1. The interaction between forest cover, edge effect and slope was the best combination explanatory of carbon stock. We observed an inverted edge effect pattern where carbon stock is higher close to the edges of the studied secondary forests. This inverted edge effect observed contradicts the usual pattern reported in the literature for mature forests. We suppose this pattern is related with a positive effect that edge conditions can have stimulating forest regeneration, but the underlying processes to explain the observed pattern should still be tested. Those results suggest that Carbon stocks in human-dominated and fragmented landscapes can be highly affected by the landscape structure, and particularly that edges conditions can favor carbon sequestration in regenerating tropical forests.

Retail Out-of-stocks in the Context of Centralized and Direct Delivery

Directory of Open Access Journals (Sweden)

Nikola Milićević

2018-03-01

Full Text Available The delivery of the right product, at the right time to the retail store, only seems to be an easy process. The smallest problem can cause the out-of-stock (OOS situation, which may prevent customers to buy products they were looking for. Consequently, it affects retailers and their suppliers through potential operational inefficiencies, sale losses and eventually the losses of their loyal customers. Starting from these problems, by using the data of a large Serbian retailer, this paper analyses out-of-stocks in the context of two alternative delivery systems, centralized and direct. For calculating OOS rates the perpetual inventory aggregation metrics was used, while the occurrence of out-of-stocks was modelled by the application of probit regression analysis. The results have shown that delivery system has a significant impact on the probability of a stock-out, indicating potential problems in the centralized system. In addition, the analysis included certain product and store characteristics that also significantly affect the average probability of stock-outs.

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2011-01-01

This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level m...

Factors Influencing the Effectiveness of Inventory Management in Manufacturing SMEs

Science.gov (United States)

Chan, Shiau Wei; Tasmin, R.; Nor Aziati, A. H.; Zuraidah Rasi, Raja; Ismail, Fadillah Binti; Yaw, Li Ping

2017-08-01

Effectiveness of inventory management is a vital part in the manufacturing organization to be more competitive. The previous studies have indicated that there are several factors influencing the effectiveness of inventory management in the organization but there is lack of researchers who carried out the research in the manufacturing small medium enterprise in Johor. Therefore, the purpose of this research is to identify the problem of inventory management faced by the manufacturing small medium enterprise and also to determine the factors that will influence the effectiveness of inventory management. In completing this research, 80 employees were selected randomly from the manufacturing small medium enterprise in Batu Pahat, Johor and they were requested to complete questionnaires. The result have shown that the problems of inventory management faced by manufacturing organization were underproduction, overproduction, stock out situation, delays in the delivery of raw materials and discrepancy of records. The factors, documentation/store records, planning, knowledge of employees/staff skill have shown to significantly influence the effectiveness of inventory management while the funds have shown slightly significant influence on the inventory management in manufacturing small medium enterprises. This quantitative study is important to the manufacturing organization in Malaysia because it provides the guidelines to the employers of manufacturing small medium enterprises in Batu Pahat, Johor.

A viability analysis for a stock/price model

Science.gov (United States)

Jerry, Chakib; Raissi, Nadia

2012-09-01

We examine the conditions for the sustainability of a stock/price system based on the use of a marine renewable resource. Instead of studying the environmental and economic interactions in terms of optimal control, we focus on the viability of the system. These viability/crisis situations are defined by a set of economic state constraints. This constraints combine a guaranteed consumption and a minimum income for fishermen. Using the mathematical concept of viability kernel, we reveal that with only economics constraints we guarantee a perennial stock/price system.

Topological Characteristics of the Hong Kong Stock Market: A Test-based P-threshold Approach to Understanding Network Complexity

Science.gov (United States)

Xu, Ronghua; Wong, Wing-Keung; Chen, Guanrong; Huang, Shuo

2017-02-01

In this paper, we analyze the relationship among stock networks by focusing on the statistically reliable connectivity between financial time series, which accurately reflects the underlying pure stock structure. To do so, we firstly filter out the effect of market index on the correlations between paired stocks, and then take a t-test based P-threshold approach to lessening the complexity of the stock network based on the P values. We demonstrate the superiority of its performance in understanding network complexity by examining the Hong Kong stock market. By comparing with other filtering methods, we find that the P-threshold approach extracts purely and significantly correlated stock pairs, which reflect the well-defined hierarchical structure of the market. In analyzing the dynamic stock networks with fixed-size moving windows, our results show that three global financial crises, covered by the long-range time series, can be distinguishingly indicated from the network topological and evolutionary perspectives. In addition, we find that the assortativity coefficient can manifest the financial crises and therefore can serve as a good indicator of the financial market development.

INVENTORIES MEASUREMENT – BETWEEN PRUDENCE AND NONPRUDENCE

Directory of Open Access Journals (Sweden)

Iulia JIANU

2010-12-01

Full Text Available In accounting, measurement is the process used to determine the value at which the items of financial statements are recognized in accounting and presented in the balance sheet and in the profit and loss account. Starting from the importance of measurement in accounting, the first study objective in this paper brings in the center of discussion the inventories measurement with the purpose to identify the main methods for inventories measurement at exit used by the economic entities listed on EuroNext Paris Exchange Stock. In the present context, when the financial crisis is still felt in the EU countries is important to note the extent to which economic entities demonstrate prudence in accounting by taking into consideration the inventories impairment at balance sheet date. Compliance with the prudence principle to integrate uncertainty in accounting measurement has the purpose to avoid the risk to transfer in the future periods the present uncertainties that are likely to strike the economic entity. One of the main consequences of this principle is to make impairments for inventories. Therefore the second objective of the present paper is to reflect the extent to which the entities under study record impairments for inventories at balance sheet date, as well as to highlight the manner in which is disclosed the information regarding the way the net realizable value can be calculated.

Towards a model-based inventory of soil organic carbon in agricultural soils for the Swiss greenhouse gas reporting

Science.gov (United States)

Staudt, K.; Leifeld, J.; Bretscher, D.; Fuhrer, J.

2012-04-01

The Swiss inventory submission under the United Nations Framework Convention on Climate Change (UNFCCC) reports on changes in soil organic carbon stocks under different land-uses and land-use changes. The approach currently employed for cropland and grassland soils combines Tier 1 and Tier 2 methods and is considered overly simplistic. As the UNFCC encourages countries to develop Tier 3 methods for national greenhouse gas reporting, we aim to build up a model-based inventory of soil organic carbon in agricultural soils in Switzerland. We conducted a literature research on currently employed higher-tier methods using process-based models in four countries: Denmark, Sweden, Finland and the USA. The applied models stem from two major groups differing in complexity - those belonging to the group of general ecosystem models that include a plant-growth submodel, e.g. Century, and those that simulate soil organic matter turnover but not plant-growth, e.g. ICBM. For the latter group, carbon inputs to the soil from plant residues and roots have to be determined separately. We will present some aspects of the development of a model-based inventory of soil organic carbon in agricultural soils in Switzerland. Criteria for model evaluation are, among others, modeled land-use classes and land-use changes, spatial and temporal resolution, and coverage of relevant processes. For model parameterization and model evaluation at the field scale, data from several long-term agricultural experiments and monitoring sites in Switzerland is available. A subsequent regional application of a model requires the preparation of regional input data for the whole country - among others spatio-temporal meteorological data, agricultural and soil data. Following the evaluation of possible models and of available data, preference for application in the Swiss inventory will be given to simpler model structures, i.e. models without a plant-growth module. Thus, we compared different allometric relations

Detailed CATHENA Model of the Wolsong 1 Pressure and Inventory Control System

Energy Technology Data Exchange (ETDEWEB)

Cha, K.H. [Korea Electric Power Research Institute, Taejon (Korea)

2002-07-01

The Detailed CATHENA model of Wolsong 1 is development to be able to simulate a theramal hydraulic behavior of heat transport system(HTS) Pressure and Inventory Control System(PNIC) at any power operation condition and during transient events such as mall LOCA(small loss of coolant inventory and small breaks in the primary system piping) and non-LOCA(loss of reactivity regulation, loss of flow, loss if Class IV power, loss of PNIC). (author). 12 refs., 7 figs., 6 tabs.

Stock prices forecasting based on wavelet neural networks with PSO

Directory of Open Access Journals (Sweden)

Wang Kai-Cheng

2017-01-01

Full Text Available This research examines the forecasting performance of wavelet neural network (WNN model using published stock data obtained from Financial Times Stock Exchange (FTSE Taiwan Stock Exchange (TWSE 50 index, also known as Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX, hereinafter referred to as Taiwan 50. Our WNN model uses particle swarm optimization (PSO to choose the appropriate initial network values for different companies. The findings come with two advantages. First, the network initial values are automatically selected instead of being a constant. Second, threshold and training data percentage become constant values, because PSO assists with self-adjustment. We can achieve a success rate over 73% without the necessity to manually adjust parameter or create another math model.

Ownership, Managerial Control and the Governance of Companies Listed on the Brussels Stock Exchange

NARCIS (Netherlands)

Renneboog, L.D.R.

1999-01-01

This paper examines how corporate control is exerted in companies listed on the Brussels Stock Exchange. There are several alternative corporate governance mechanisms which may play a role in disciplining poorly performing management: blockholders (holding companies, industrial companies, families

Timber resource statistics for the Yakataga inventory unit, Alaska, 1976.

Science.gov (United States)

Willem W.S. van Hees

1985-01-01

Statistics on forest area, total gross and net timber volumes, and annual net growth and mortality are presented from the 1976 timber inventory of the Yakataga unit, Alaska. Timberland area is estimated at 209.3 thousand acres (84.7 thousand ha), net growing stock volume at 917.1 million cubic feet (26.0 million m3), and annual net growth and...

Which stocks are profitable? A network method to investigate the effects of network structure on stock returns

Science.gov (United States)

Chen, Kun; Luo, Peng; Sun, Bianxia; Wang, Huaiqing

2015-10-01

According to asset pricing theory, a stock's expected returns are determined by its exposure to systematic risk. In this paper, we propose a new method for analyzing the interaction effects among industries and stocks on stock returns. We construct a complex network based on correlations of abnormal stock returns and use centrality and modularity, two popular measures in social science, to determine the effect of interconnections on industry and stock returns. Supported by previous studies, our findings indicate that a relationship exists between inter-industry closeness and industry returns and between stock centrality and stock returns. The theoretical and practical contributions of these findings are discussed.

Justification of evaluation criteria of the effectiveness of choice of spare parts stored in the warehouse of the transport company to maintain in good condition of its rolling stock

Directory of Open Access Journals (Sweden)

Antonyuk O.P.

2016-08-01

Full Text Available Support rolling stock of transport in good repair can be carried out using replacement parts that are stored on in the warehouses of transport enterprise and spare parts that are purchased as the need arises. For the uninterrupted transport services transport enterprise must have a certain amount of stock of spare parts at a given time. Rational organization of storage and inventory control of spare parts for motor plant affects the reducing operating costs and improving profitability of the transportation process. In the article the criteria for evaluating the effectiveness of choice of spare parts stored in the warehouse of the transport company to maintain in good condition of its rolling stock, taking into account the totality of the costs of purchase, transportation and storage of spare parts. Using these criteria allows to determine the advisability of keeping spare parts in stock of transport and procurement of necessary spare parts, provided the minimal costs of spare parts.

Chinese version of the separation-individuation inventory.

Science.gov (United States)

Tam, Wai-Cheong Carl; Shiah, Yung-Jong; Chiang, Shih-Kuang

2003-08-01

The importance of the separation-individuation process in object relations theory is well known in disciplines of psychology, counseling, and human development. Based on the Separation-Individuation Inventory of Christenson and Wilson, which measures the manifestations of disturbances in this process, a Chinese version of the inventory was developed. For college students Cronbach coefficient alpha was .89, and test-retest reliability over 28 days was .77. The scores of the inventory had positive correlations with both the number of borderline personality characteristics and the Individualism-Collectivism Scale, respectively. Also, the mean score on the inventory of patients diagnosed with borderline personality disorder was significantly higher than that of the two normal control groups (ns = 564). Thus the inventory possessed satisfactory construct validity. Cultural differences regarding the separation-individuation process need to be investigated further.

Timber resource statistics for the Copper River inventory unit, Alaska, 1968.

Science.gov (United States)

Karl M. Hegg

1975-01-01

This first intensive forest inventory of Alaska's Copper River Valley found a commercial forest area of 287,800 acres with 303.8 million cubic feet of growing stock. Additionally, a noncommercial stratum was examined that had substantial standing volume but did not meet the growth criteria for commercial forest land. This stratum contained 152,800 acres with a...

Attitudes and opinions of nursing and medical staff regarding the supply and storage of medicinal products before and after the installation of a drawer-based automated stock-control system.

Science.gov (United States)

Ardern-Jones, Joanne; Hughes, Donald K; Rowe, Philip H; Mottram, David R; Green, Christopher F

2009-04-01

This study assessed the attitudes of Emergency Department (ED) staff regarding the introduction of an automated stock-control system. The objectives were to determine attitudes to stock control and replenishment, speed of access to the system, ease of use and the potential for future uses of the system. The study was carried out in the Countess of Chester Hospital NHS Foundation Trust (COCH) ED, which is attended by over 65,000 patients each year. All 68 ED staff were sent pre-piloted, semi-structured questionnaires and reminders, before and after automation of medicines stock control. Pre-implementation, 35 staff (66.1% of respondents) reported that problems occurred with access to medicine storage keys 'very frequently' or 'frequently'. Twenty-eight (52.8%) respondents 'agreed' or 'strongly agreed' that medicines were quickly accessed, which rose to 41 (77%) post-automation (P fluids and refrigerated items. Twenty-seven (51.9%) staff reported access to the system within 1 min and 17 (32.7%) staff reported access within 1-2 min. The majority of staff found the system 'easy' or 'very easy' to use and there was a non-significant relationship between previous use of information technology and acceptance of the system. From a staff satisfaction perspective, automation improved medicines storage, security and stock control, and addressed the problem of searching for keys to storage areas. Concerns over familiarity with computers, queuing, speed of access and an improved audit trail do not appear to have been issues, when compared with the previous manual storage of medicines.

Uniformity: The key to better inventory management

International Nuclear Information System (INIS)

Boshears, G.

1993-01-01

The objective of this paper is to show how uniformity in describing parts and materials can be the key ingredient to more effective inventory management. Although most nuclear utilities have some type of computer system for maintenance management as well as materials tracking, few have a system to provide the various users with complete information about parts and material in stock. One of the industry's most perplexing problems is How do you know, and find, the item you need to repair a particular piece of equipment or component? In many instances it is easier to order a new one from the manufacturer rather than try to find it on-site, which can result in inaccurate usage records, over-stocking, frustration, and strain on cash flow. What is needed is a higher degree of uniformity within a station, and a utility, of catalog descriptions for parts and material that will satisfy all users-planners, craftsmen, warehouse personnel, and buyers. The results of attaining this uniformity are improved performance through searchability, duplicate stock avoidance, interchangeability, substitutability, and more accurate bills of material; economic benefits will also be noted

Genetic algorithm to optimize two-echelon inventory control system for perishable goods in terms of active packaging

Directory of Open Access Journals (Sweden)

Babak Yousefi Yegane

2012-01-01

Full Text Available This paper considers an inventory control policy for a two-echelon inventory control system with one supplier-one buyer. We consider the case of deteriorating items which lead to shortage in supply chain. Therefore, it is necessary to decrease the deterioration rate by adding some specification to the packaging of these items that is known as active packaging. Although this packaging can reduce the deteriorating rate of products, but may be increases the cost of both supplier and buyer. Because of the complexity of the mathematical model, a genetic algorithm has been developed to determine the best policy of this inventory control system.

Numerical research of the optimal control problem in the semi-Markov inventory model

International Nuclear Information System (INIS)

Gorshenin, Andrey K.; Belousov, Vasily V.; Shnourkoff, Peter V.; Ivanov, Alexey V.

2015-01-01

This paper is devoted to the numerical simulation of stochastic system for inventory management products using controlled semi-Markov process. The results of a special software for the system’s research and finding the optimal control are presented

Numerical research of the optimal control problem in the semi-Markov inventory model

Energy Technology Data Exchange (ETDEWEB)

Gorshenin, Andrey K. [Institute of Informatics Problems, Russian Academy of Sciences, Vavilova str., 44/2, Moscow, Russia MIREA, Faculty of Information Technology (Russian Federation); Belousov, Vasily V. [Institute of Informatics Problems, Russian Academy of Sciences, Vavilova str., 44/2, Moscow (Russian Federation); Shnourkoff, Peter V.; Ivanov, Alexey V. [National research university Higher school of economics, Moscow (Russian Federation)

2015-03-10

This paper is devoted to the numerical simulation of stochastic system for inventory management products using controlled semi-Markov process. The results of a special software for the system’s research and finding the optimal control are presented.

PERBAIKAN KEBIJAKAN PENGENDALIAN PERSEDIAAN JUST IN TIME KOMPONEN PRODUK MAIN FLOOR SIDE LH PADA PT GAYA MOTOR

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Bella Suciana Istiqomah

2015-06-01

Full Text Available PT . Gaya Motor is a manufacturing company that is engaged in the assembly and production of automotive components incorporated in the group of PT Astra International.Perusahaan implement inventory control system Just In Time.Kanban’s supplier with safety stock of 0.5 days plus a safety stock of 0.5 extra days beyond the kanban. The study was conducted on the material supply products Main Floor Side LH SA - 001 , SA - 002 , SA - 003 , SA - 004 , SA - 005 , SA - 006 , SA - 007 , SA - 008 and SA - 009. Problems faced by the company are the high amount of inventory caused by inaccurate inventory systems and fault current in raw material procurement procedures. The purpose of this study was to evaluate the company's current inventory control system and propose improvements inventory control system that can minimize inventory costs compared to the cost of inventory at the company's current inventory system.Kanban inventory method supplier company currently has a total cost of inventory of Rp 318.861.462,00. Supplier kanban inventory control methods with safety stock kanban 0.1 days has a total cost of inventory of Rp 158.703.378,00. Inventory control methods Two - Bin Replenishment has a total inventory cost of Rp 98.497.214,00. From the results of these calculations, the minimum inventory cost obtained by using the method of inventory Two - Bin Replenishment, and made proposals related to changes in inventory control system.

Inventory control for a perishable product with non-stationary demand

NARCIS (Netherlands)

Pauls-Worm, K.G.J.

2016-01-01

Globally, around one-third of the edible parts of perishable food products is wasted every year. Adequate logistics management of the food supply chain is of importance. Inventory control of processed fresh food with a best-before or use-by date deals with the questions how much to order and how

Equity portfolio optimization: A DEA based methodology applied to the Zagreb Stock Exchange

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Margareta Gardijan

2015-10-01

Full Text Available Most strategies for selection portfolios focus on utilizing solely market data and implicitly assume that stock markets communicate all relevant information to all market stakeholders, and that these markets cannot be influenced by investor activities. However convenient, this is a limited approach, especially when applied to small and illiquid markets such as the Croatian market, where such assumptions are hardly realistic. Thus, there is a demand for including other sources of data, such as financial reports. Research poses the question of whether financial ratios as criteria for stock selection are of any use to Croatian investors. Financial and market data from selected publicly companies listed on the Croatian capital market are used. A two-stage portfolio selection strategy is applied, where the first stage involves selecting stocks based on the respective Data Envelopment Analysis (DEA efficiency scores. DEA models are becoming popular in stock portfolio selection given that the methodology includes numerous models that provide a great flexibility in selecting inputs and outputs, which in turn are considered as criteria for portfolio selection. Accordingly, there is much room for improvement of the current proposed strategies for selecting portfolios. In the second stage, two portfolio-weighting strategies are applied using equal proportions and score-weighting. To show whether these strategies create outstanding out–of–sample portfolios in time, time-dependent DEA Window Analysis is applied using a reference time of one year, and portfolio returns are compared with the market portfolio for each period. It is found that the financial data are a significant indicator of the future performance of a stock and a DEA-based portfolio strategy outperforms market return.

Dynamics Analysis Of Land-Based Carbon Stock In The Region Of Samarinda East Kalimantan Province

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Zikri Azham

2017-10-01

Full Text Available This study aims to determine the potential dynamics of carbon stocks in various land cover classes in the city of Samarinda in the calculation of carbon stocks land cover only devided into three 3 Class Land Cover CLC is a secondary forest CLC CLC thickets and CLC shrubs. Research results show that the above ground carbon AGC stocks on Secondary Forest Land Cover Class average of 71.93 tonnesha the land cover classes thickets of 32.34 tonnes hectares and shrubs land cover classes of 19.66 tonnes hectare. The carbon stocks in 2009 amounted to 2589929 tonnes in 2012 there were 2347477 tons and in 2015 there were 2201005 tonnes. Estimated decrease in land-based stock carbon in the city of Samarinda during the period 2009-2015 amounted to 388943 tonnes or an average of 70170 tonnes per year or approximately 2.73year or the emissions in the field of land amounting to 254538 tonnes of CO2 equivalent.

A study on the effect of P/E and PEG ratios on stock returns: Evidence from Tehran Stock Exchange

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Seyyed Ali Lajevardi

2014-07-01

Full Text Available This paper studies the effect of the ratios of P/E and PEG on stock returns of the firms accepted on Tehran Stock Exchange. The study uses regression and Pearson Correlation Coefficient based on the performance of 138 firms over the period 2004- 2009 according to the Iranian calendar to investigate the effects of P/E and PEG on stock returns. The study also uses the models originally proposed by Chahin and Choudhry (2010 [Chahin, S., & Choudhry, T. (2010. Price to earnings, growth radio and value growth based strategies. Social Science Research Network, 19(4.] to discuss the strategies of investing on stocks. The results show that the ratio of P/E had more effect on stock returns than the ratio of PEG and stocks returns had a direct relationship with P/E and an inverse relationship with PEG. In addition, the returns of growth stock were more than value stock.

The use and usefulness of inventory-based management planning to forest management

DEFF Research Database (Denmark)

Toft, Maja Nastasia Juul; Adeyeye, Yemi; Lund, Jens Friis

2015-01-01

-structured interviews, participatory rural appraisal exercises and analyses of aerial photographs. First, we find that the operational plans supposed to guide community-level management are based on sub-standard forest inventories, which limits their potential role in practical forest management. Second, we find...... of their forests in the sense that their impressions of past and current forest condition are mirrored in what we can observe from analysis of change in forest condition based on aerial photographs. Based on these results we question the usefulness of inventory-based management planning in the context of community...

Limits to the reliability of size-based fishing status estimation for data-poor stocks