scholarly journals Additive Pattern Database Heuristics

2004 ◽  
Vol 22 ◽  
pp. 279-318 ◽  
Author(s):  
A. Felner ◽  
R. E. Korf ◽  
S. Hanan
Keyword(s):  
Vertex Cover ◽  
Problem Instance ◽  
Standard Pattern ◽  
Evaluation Functions ◽  
Dynamic Partitioning ◽  
Towers Of Hanoi ◽  
Static Partitioning ◽  
Pros And Cons ◽  
The Cost ◽  
Pattern Databases

We explore a method for computing admissible heuristic evaluation functions for search problems. It utilizes pattern databases, which are precomputed tables of the exact cost of solving various subproblems of an existing problem. Unlike standard pattern database heuristics, however, we partition our problems into disjoint subproblems, so that the costs of solving the different subproblems can be added together without overestimating the cost of solving the original problem. Previously, we showed how to statically partition the sliding-tile puzzles into disjoint groups of tiles to compute an admissible heuristic, using the same partition for each state and problem instance. Here we extend the method and show that it applies to other domains as well. We also present another method for additive heuristics which we call dynamically partitioned pattern databases. Here we partition the problem into disjoint subproblems for each state of the search dynamically. We discuss the pros and cons of each of these methods and apply both methods to three different problem domains: the sliding-tile puzzles, the 4-peg Towers of Hanoi problem, and finding an optimal vertex cover of a graph. We find that in some problem domains, static partitioning is most effective, while in others dynamic partitioning is a better choice. In each of these problem domains, either statically partitioned or dynamically partitioned pattern database heuristics are the best known heuristics for the problem.

scholarly journals Model Integrasi Penjadwalan Batch dan Penjadwalan Preventive Maintenance dengan Kriteria Minimisasi Biaya Simpan, Biaya Setup, Biaya Pm, serta Biaya Rework pada Mesin Stabil

2014 ◽  
Vol 5 (1) ◽  
pp. 397
Author(s):  
Zahedi Zahedi
Keyword(s):  
Preventive Maintenance ◽  
Batch Scheduling ◽  
Problem Instance ◽  
Production Schedule ◽  
Batch Production ◽  
Setup Costs ◽  
The Cost ◽  
Single Batch

This study developed a model of batch scheduling involving the unavailability machine to minimize setup costs, cost of preventive maintenance and the cost of rework in a stable machine. This model is considered necessary in order to understand the effect of the unavailability machine for production runs and to understand the effect on the batch production schedule. The results of this study indicate that the first and last run will not give single batch. Given a hypothetical example of how the model and algorithm developed solve the problem instance. 

Measures to Relieve the Stress of Water

2013 ◽  
Vol 361-363 ◽  
pp. 636-639 ◽  
Author(s):  
Shi Kai Duan ◽  
Guo Shi Shen ◽  
Zhen Dong Shan ◽  
Yan Dong ◽  
Kai Zheng ◽  
...  
Keyword(s):  
Water Resources ◽  
Water Shortage ◽  
The United States ◽  
Three Solutions ◽  
Total Cost ◽  
Pros And Cons ◽  
Water Strategy ◽  
The Cost ◽  
Significant Regional Difference

In order to develop realistic water resources strategy, we initially analyze the situation of water resources in the United States which present a significant regional difference. Then on the basis of previous studies, we propose the cost formulas of water storage, movement and desalinization. By analyzing the practical application, along with pros and cons of the above three solutions accordingly, we consider that a comprehensive utilization of these measures will be the best water strategy for America to solve the water shortage problem. Later we apply the conclusion to a case study of Southern California, we propose an optimization model which aims to minimize the total cost of the water strategy, and then use Lingo to solve the problem. Results show that 5.946 billion cubic meters of water by transferring is the best way to make up for the water use gap in 2025 and the total cost is 2.94 billion dollars. Finally, we summarize the strengths and weaknesses of our paper. What needs to be emphasized is that our model can also be adapted into the analysis of other states, which shows great flexibility.

scholarly journals Dyslexia and digital technology

2015 ◽  
Vol 1 (3) ◽  
Author(s):  
Taylor Chester
Keyword(s):  
Assistive Technology ◽  
Education System ◽  
Digital Technology ◽  
Assistive Technologies ◽  
High Tech ◽  
Technology In The Classroom ◽  
Different Types ◽  
Pros And Cons ◽  
The Cost ◽  
User Friendly

This research manuscript investigates how technology can be used to help students with dyslexia. Using a Google Forms survey and an interview with an expert on the topic, different types of technologies, the pros and cons of using assistive technology, and recommendations for implementing assistive technology in the classroom are listed.  It was found that assistive technology is beneficial for students with dyslexia, but each student will benefit from different technologies. The main challenges with assistive technology that this research project uncovered included, glitches, not being user friendly, and the cost of some of these technologies. These problems apply mainly to higher tech assistive technologies, so including low tech assistive technologies in the classroom as well as high tech options could benefit students and avoid some of these challenges. Understanding some of the different assistive technologies that are available and beneficial for students with dyslexia is important for those involved in the education system so that we can give students with dyslexia the tools that they need to succeed. When educators know about, understand how to use, and have the resources to acquire assistive technologies then technology can be used to help students with dyslexia.

scholarly journals TRUE ORTHO GENERATION OF URBAN AREA USING HIGH RESOLUTION AERIAL PHOTOS

2016 ◽  
Vol III-4 ◽  
pp. 3-10
Author(s):  
Yong Hu ◽  
David Stanley ◽  
Yubin Xin
Keyword(s):  
High Resolution ◽  
Literature Review ◽  
Visibility Analysis ◽  
Aerial Photos ◽  
Imaging Geometry ◽  
Innovative Solutions ◽  
Pros And Cons ◽  
Quality Rating ◽  
The Cost ◽  
Critical Literature

The pros and cons of existing methods for true ortho generation are analyzed based on a critical literature review for its two major processing stages: visibility analysis and occlusion compensation. They process frame and pushbroom images using different algorithms for visibility analysis due to the need of perspective centers used by the z-buffer (or alike) techniques. For occlusion compensation, the pixel-based approach likely results in excessive seamlines in the ortho-rectified images due to the use of a quality measure on the pixel-by-pixel rating basis. In this paper, we proposed innovative solutions to tackle the aforementioned problems. For visibility analysis, an elevation buffer technique is introduced to employ the plain elevations instead of the distances from perspective centers by z-buffer, and has the advantage of sensor independency. A segment oriented strategy is developed to evaluate a plain cost measure per segment for occlusion compensation instead of the tedious quality rating per pixel. The cost measure directly evaluates the imaging geometry characteristics in ground space, and is also sensor independent. Experimental results are demonstrated using aerial photos acquired by UltraCam camera.

Cost and Yield Comparison of Wafer-to-Wafer, Die-to-Wafer, and Die-to-Die Bonding

2014 ◽  
Vol 2014 (1) ◽  
pp. 000624-000629
Author(s):  
Amy Palesko ◽  
Chet Palesko
Keyword(s):  
Adhesive Bonding ◽  
Defect Density ◽  
Main Process ◽  
Advantages And Disadvantages ◽  
Trade Offs ◽  
3D Assembly ◽  
Multiple Process ◽  
Pros And Cons ◽  
Die Bonding ◽  
The Cost

There are multiple process options and technologies to consider when creating a product that requires 3D integration. Bonding two wafers (or two die) can be accomplished in various ways, such as with thermocompression, fusion, or adhesive bonding. However, the best assembly process cannot be determined by only studying the pros and cons of the bonding technology itself. There are also three main process flows to consider when pursuing 3D assembly: wafer-to-wafer, die-to-wafer, and die-to-die bonding. This paper will compare the cost and yield for each of these process flows, all of which have advantages and disadvantages depending on the application. Activity based cost modeling will be used to construct three basic process flows, one for each bonding option. The process flows will each be divided into a series of activities, and the total cost of each activity will be accumulated. A variety of cost and yield trade-offs will be conducted using these process flows. The variables the trade-offs will focus on will include die size, throughput, incoming wafer cost, incoming wafer defect density, and residual die defect density. The goal of this analysis is to understand the variables that impact cost and yield when bonding wafers and/or die for a product that requires 3D assembly.

Choosing Supports

2019 ◽  
pp. 217-231
Author(s):  
Robert L. Klitzman
Keyword(s):  
Mental Health ◽  
Support Groups ◽  
Mental Health Treatment ◽  
Social Supports ◽  
Individual Psychotherapy ◽  
Health Treatment ◽  
Online Groups ◽  
Face To Face ◽  
Pros And Cons ◽  
The Cost

Patients struggle to cope with ethical, social, and psychological challenges in several ways, from trying to manage expectations to seeking various forms of support from family, friends, and others. Shame, stigma, and disappointment lead many patients to disclose their infertility and treatment to few, if any, family members; and consequently, they derive little support from them. Abortion or embryo screening due to a mutation, for instance, can be difficult to reveal because outsiders may be pro-life. Patients respond to perceived shortcomings of families and friends in several ways—from trying to educate these individuals or limit interactions to seeking new supports, whether from fellow patients or psychotherapists. Patients frequently seek new social supports—from formal to informal, from in person to online, and from individual psychotherapy to support groups and large organizations. Many prospective parents, who might benefit from mental health treatment, resent the cost as insurance commonly covers little, if any, of the expense. Face-to-face and online groups each offer pros and cons.

scholarly journals Use of Electrocoagulation for Treatment of Pharmaceutical Compounds in Water/Wastewater: A Review Exploring Opportunities and Challenges

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2105
Author(s):  
Rahat Alam ◽  
Mohd Sheob ◽  
Bilal Saeed ◽  
Saif Ullah Khan ◽  
Maryam Shirinkar ◽  
...  
Keyword(s):  
Process Parameters ◽  
Pharmaceutical Compounds ◽  
Removal Mechanism ◽  
Operational Cost ◽  
Pharmaceutical Wastewater ◽  
Treatment Technologies ◽  
Pros And Cons ◽  
Co Precipitation ◽  
Industrial Level ◽  
The Cost

Increasing dependency on pharmaceutical compounds including antibiotics, analgesics, antidepressants, and other drugs has threatened the environment as well as human health. Their occurrence, transformation, and fate in the environment are causing significant concerns. Several existing treatment technologies are there with their pros and cons for the treatment of pharmaceutical wastewater (PWW). Still, electrocoagulation is considered as the modern and decisive technology for treatment. In the EC process, utilizing electricity (AC/DC) and electrodes, contaminants become coagulated with the metal hydroxide and are separated by co-precipitation. The main mechanism is charge neutralization and adsorption of contaminants on the generated flocs. The range of parameters affects the EC process and is directly related to the removal efficiency and its overall operational cost. This process only could be scaled up on the industrial level if process parameters become optimized and energy consumption is reduced. Unfortunately, the removal mechanism of particular pharmaceuticals and complex physiochemical phenomena involved in this process are not fully understood. For this reason, further research and reviews are required to fill the knowledge gap. This review discusses the use of EC for removing pharmaceuticals and focuses on removal mechanism and process parameters, the cost assessment, and the challenges involved in mitigation.

Natural Resource Damage Assessments: Is Cooperation a Good Thing?

2017 ◽  
Vol 2017 (1) ◽  
pp. 3091-3111
Author(s):  
Robert Haddad ◽  
Brian D. Israel
Keyword(s):  
Natural Resource ◽  
Oil Pollution ◽  
Effective Means ◽  
The United States ◽  
Working Relationships ◽  
Common Denominator ◽  
Environmental Response ◽  
Advantages And Disadvantages ◽  
Pros And Cons ◽  
The Cost

Abstract It has been nearly 55 years since the United States enacted the Clean Water Act (CWA) in which natural resource damages (NRD) were codified.1 The NRD cause of action, originally derived from the public trust doctrine and common law, was later integrated into the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in 1980 and into the Oil Pollution Act (OPA) in 1990. In response to the establishment of CERCLA and OPA, the U.S. Department of the Interior (DOI) was charged with developing and promulgating NRD regulations under CERCLA while the National Oceanic and Atmospheric Administration (NOAA) was charged to do so under OPA. Originally, DOI’s approach to assessing NRD under CERCLA emphasized monetary compensation, as this was a simple common denominator. Later, under OPA, NOAA’s regulations allowed NRD to be determined by, and compensated with, an ecological currency, e.g., using a Habitat or Resource Equivalency Approach (HEA2, REA3). This focus on putting restoration front and center in NRD assessments (NRDAs)4 was ultimately integrated into the DOI regulations in 2008. A critical and evolving aspect of NRDAs has been the concept of cooperation between the responsible party (RP) and the trustees in undertaking the NRDA (e.g., Israel 2006a; Connor and Gouguet 2005; Reinharz et al. 2005). This approach, supported by NOAA and others, is an effective means to identify and resolve legal uncertainties through stipulations and create working relationships that effectively focus on assessment resolution and restoration implementation; the ultimate outcome being a more rapid path to restoration and a significant decrease in litigation and other transactional costs. Over the past decade, the benefits of cooperative assessments have been questioned. It has been suggested that cooperative NRDAs do little to move the process forward in a timely manner. It has been further implied that cooperation equates to RPs paying up front for the cost of the assessment while the trustees conduct the assessment. In truth, both perspectives are correct, the reality being that cooperation means different things to different people. In this paper, we examine the historical underpinnings of the NRDA regulations, how this led to the development of the cooperative, restoration-based NRDA process, and the pros and cons of the cooperative NRDA process. We identify some of the inherent political, technical, cultural, and legal challenges with the cooperative NRDA paradigm as well as some of the benefits. Finally, we discuss the advantages and disadvantages of cooperation in the context of future NRDA cases, with an eye towards identification of specific processes that may help better understand or predict if cooperation is the best path forward for resolution of NRD liability.

scholarly journals Destruction of buildings and use of materials from renovated urban territories

Vestnik MGSU ◽  
2020 ◽  
pp. 271-293 ◽  
Author(s):  
Sergey A. Kolodyazhny ◽  
Sergei N. Zolotukhin ◽  
Anatoly A. Abramenko ◽  
Yekaterina A. Artemova
Keyword(s):  
Construction Materials ◽  
Actual Problem ◽  
Environment Friendly ◽  
Environmental Friendliness ◽  
Urban Territories ◽  
Theoretical Generalization ◽  
Pros And Cons ◽  
The Cost ◽  
Building Demolition

Introduction. Reuse of construction materials, products, and structures from demolished buildings and installations is an actual problem. The solution to it will improve the ecological situation. The study is aims at the determination of the causes of urban area renovation and searches for the most efficient technologies of building demolition with the reuse of the generated materials, products, and structures. Materials and methods. The study used systematization, structural analysis, comparative analysis, a theoretical generalization of the data obtained in a detailed analysis of literary and statistical sources, field surveys of objects. When field examining, photography methods were used. Results. Existing technologies of the building demolition, construction waste recovery, and reuse of construction materials generated using innovative item-by-item demolition technologies were revealed and systematized. Causes and main trends of urban territory renovation were analyzed. The paper studied Russian and foreign technologies of the building and installation demolition. The pros and cons of various demolition types are shown in terms of their environmental friendliness and economic efficiency. Conclusions. The experience of constructing low-rise buildings and intrasettlement roads showed that the item-by-item disassembly of buildings using modern equipment and machinery with the subsequent reuse of construction materials, products, and structures is efficient, economical, and environment-friendly. It is proven that the reuse of construction materials, products, and structures results in a significant reduction in the cost of erected installations. The results of the study can be applied in low-rise construction around the world.

scholarly journals Enhanced Partial Expansion A*

2014 ◽  
Vol 50 ◽  
pp. 141-187 ◽  
Author(s):  
M. Goldenberg ◽  
A. Felner ◽  
R. Stern ◽  
G. Sharon ◽  
N. Sturtevant ◽  
...  
Keyword(s):  
Memory Performance ◽  
A Priori ◽  
Experimental Studies ◽  
Optimal Solution ◽  
Theoretical Studies ◽  
Specific Knowledge ◽  
Novel Variant ◽  
Branching Factor ◽  
The Cost ◽  
Pattern Databases

When solving instances of problem domains that feature a large branching factor, A* may generate a large number of nodes whose cost is greater than the cost of the optimal solution. We designate such nodes as surplus. Generating surplus nodes and adding them to the OPEN list may dominate both time and memory of the search. A recently introduced variant of A* called Partial Expansion A* (PEA*) deals with the memory aspect of this problem. When expanding a node n, PEA* generates all of its children and puts into OPEN only the children with f = f (n). n is re-inserted in the OPEN list with the f -cost of the best discarded child. This guarantees that surplus nodes are not inserted into OPEN. In this paper, we present a novel variant of A* called Enhanced Partial Expansion A* (EPEA*) that advances the idea of PEA* to address the time aspect. Given a priori domain- and heuristic- specific knowledge, EPEA* generates only the nodes with f = f(n). Although EPEA* is not always applicable or practical, we study several variants of EPEA*, which make it applicable to a large number of domains and heuristics. In particular, the ideas of EPEA* are applicable to IDA* and to the domains where pattern databases are traditionally used. Experimental studies show significant improvements in run-time and memory performance for several standard benchmark applications. We provide several theoretical studies to facilitate an understanding of the new algorithm.

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