Next-fit bin packing with random piece sizes

1989 ◽  
Vol 26 (3) ◽  
pp. 503-511 ◽  
Author(s):  
Shlomo Halfin

Investigations into time-slotted communication channels for transmission of data packets led us to analyze the stochastic behavior of the next-fit bin packing algorithm. In this paper we obtain results for general piece-size distributions and truncated distributions, we calculate explicit solutions for the case of the truncated exponential, and we apply the results to calculate the maximal throughput of the time-slotted communication channel.

1989 ◽  
Vol 26 (03) ◽  
pp. 503-511
Author(s):  
Shlomo Halfin

Investigations into time-slotted communication channels for transmission of data packets led us to analyze the stochastic behavior of the next-fit bin packing algorithm. In this paper we obtain results for general piece-size distributions and truncated distributions, we calculate explicit solutions for the case of the truncated exponential, and we apply the results to calculate the maximal throughput of the time-slotted communication channel.


2021 ◽  
Vol 26 ◽  
pp. 1-19
Author(s):  
Martín Farach-Colton ◽  
Katia Leal ◽  
Miguel A. Mosteiro ◽  
Christopher Thraves Caro

We consider the Windows Scheduling (WS) problem, which is a restricted version of Unit-Fractions Bin Packing, and it is also called Inventory Replenishment in the context of Supply Chain. In brief, WS problem is to schedule the use of communication channels to clients. Each client c i is characterized by an active cycle and a window w i . During the period of time that any given client c i is active, there must be at least one transmission from c i scheduled in any w i consecutive time slots, but at most one transmission can be carried out in each channel per time slot. The goal is to minimize the number of channels used. We extend previous online models, where decisions are permanent, assuming that clients may be reallocated at some cost. We assume that such cost is a constant amount paid per reallocation. That is, we aim to minimize also the number of reallocations. We present three online reallocation algorithms for Windows Scheduling. We evaluate experimentally multiple variants of these protocols showing that, in practice, all three achieve constant amortized reallocations with close to optimal channel usage. Our simulations also expose interesting tradeoffs between reallocations and channel usage. We introduce a new objective function for WS with reallocations that can be also applied to models where reallocations are not possible. We analyze this metric for one of the algorithms that, to the best of our knowledge, is the first online WS protocol with theoretical guarantees that applies to scenarios where clients may leave and the analysis is against current load rather than peak load. Using previous results, we also observe bounds on channel usage for one of the algorithms.


2015 ◽  
Vol 55 (1) ◽  
pp. 44-68 ◽  
Author(s):  
Stephanie A. Smith ◽  
Alyssa Patmos ◽  
Margaret J. Pitts

This study examines teleworkers’ job satisfaction related to the use of and satisfaction with a variety of communication channels and workers’ personality type. U.S. teleworkers ( N = 384) completed an online survey and self-reported on dimensions of communication channel satisfaction, job satisfaction, and personality. Results indicated that extraversion, openness, agreeableness, and conscientiousness are positively correlated with job satisfaction. Additionally, significant moderating effects were found for the relationship between openness and phone and video communication, and agreeableness and phone communication on job satisfaction. Findings from this study yield important practical implications for organizations including suggestions for optimizing communication satisfaction for employees of differing personality types and recommendations to help organizations effectively hire and retain teleworkers.


2018 ◽  
Author(s):  
Arriel Benis ◽  
Nissim Harel ◽  
Refael Barak Barkan ◽  
Einav Srulovici ◽  
Calanit Key

BACKGROUND Data collected by health care organizations consist of medical information and documentation of interactions with patients through different communication channels. This enables the health care organization to measure various features of its performance such as activity, efficiency, adherence to a treatment, and different quality indicators. This information can be linked to sociodemographic, clinical, and communication data with the health care providers and administrative teams. Analyzing all these measurements together may provide insights into the different types of patient behaviors or more accurately to the different types of interactions patients have with the health care organizations. OBJECTIVE The primary aim of this study is to characterize usage profiles of the available communication channels with the health care organization. The main objective is to suggest new ways to encourage the usage of the most appropriate communication channel based on the patient’s profile. The first hypothesis is that the patient’s follow-up and clinical outcomes are influenced by the patient’s preferred communication channels with the health care organization. The second hypothesis is that the adoption of newly introduced communication channels between the patient and the health care organization is influenced by the patient’s sociodemographic or clinical profile. The third hypothesis is that the introduction of a new communication channel influences the usage of existing communication channels. METHODS All relevant data will be extracted from the Clalit Health Services data warehouse, the largest health care management organization in Israel. Data analysis process will use data mining approach as a process of discovering new knowledge and dealing with processing data extracted with statistical methods, machine learning algorithms, and information visualization tools. More specifically, we will mainly use the k-means clustering algorithm for discretization purposes and patients’ profile building, a hierarchical clustering algorithm, and heat maps for generating a visualization of the different communication profiles. In addition, patients’ interviews will be conducted to complement the information drawn from the data analysis phase with the aim of suggesting ways to optimize existing communication flows. RESULTS The project was funded in 2016. Data analysis is currently under way and the results are expected to be submitted for publication in 2019. Identification of patient profiles will allow the health care organization to improve its accessibility to patients and their engagement, which in turn will achieve a better treatment adherence, quality of care, and patient experience. CONCLUSIONS Defining solutions to increase patient accessibility to health care organization by matching the communication channels to the patient’s profile and to change the health care organization’s communication with the patient to a highly proactive one will increase the patient’s engagement according to his or her profile. INTERNATIONAL REGISTERED REPOR RR1-10.2196/10734


Author(s):  
Reemiah Alotaibi ◽  
Muthu Ramachandran ◽  
Ah-Lian Kor ◽  
Amin Hosseinian-Far

Social media has become an integral part of many people's lives around the world. The main use of this communication channel is to connect with social circles. It is also widely used for commercial and business purposes. Governments are also keen to use social media as an alternative to the traditional communication channels. Nonetheless, when the level of use of social media in the government is compared to other fields, a clear gap becomes apparent. This chapter investigates the adoption of social media as a communication channel between citizens, public agencies and government departments; and considers a wide range of factors that affect the issue from the perspective of public agencies. This chapter presents an extensive literature review and proposes a framework that organises the critical factors that affect public agencies' efforts while implementing social media. We also provide a list of hypotheses to validate and evaluate the significance of these factors.


2020 ◽  
Vol 21 (1) ◽  
pp. 250-266
Author(s):  
Zehavit Kohen ◽  
Orit Herscovitz ◽  
Yehudit Judy Dori

Facilitating students' chemical literacy is a focal point of current science education. This study examines views of chemists and chemistry teachers on chemical literacy and, more broadly, on scientific literacy of four kinds of stakeholders: scientists, teachers, STEM students, and the educated public. We explored the views of 347 participants, representing the four stakeholder groups with diversified scientific literacy, and an Ask-a-Scientist public website as a communication channel for facilitating chemical literacy through posing questions. Research tools included interviews, open-ended questionnaires, and questions retrieved from the website. We found that the questions posed on the website expressed a range of levels of chemical literacy that the students had constructed. The stakeholder groups expressed diverse perspectives of their experiences using various types of communication channels, arguing for the need to encourage students to pose questions and receive scientists' responses. Our study is placed in the larger context of scientific literacy and communication channels, as it takes the example of chemical literacy, with a focus on communications among scientists and chemistry teachers in the context of an Ask-a-Scientist website. It has established a link between responses of various stakeholders and the literature definitions regarding scientific literacy with focus on chemical literacy. From a practical viewpoint, the study presents a productive communication channel for posing questions in the context of chemistry and other sciences. Methodologically, this study includes the design of tools for analyzing both the views of different stakeholders and for evaluating the complexity level of chemistry questions, which might serve chemistry educators.


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