Analysis of Inter-Domain Collaborative Routing: Provider Competition for Clients

Nicholes, Martin O,Chuah, Chen-Nee,Wu, Shyhtsun Felix,Mukherjee, Biswanath The Korea Institute of Information and Commucation 2011 Journal of communications and networks Vol.13 No.5

Any server offering a routing service in the Internet would naturally be in competition for clients, and clients may need to utilize service from a specific server in order to achieve a desired result. We study the various properties of this competition, such as the fraction of route requests handled by a routing service provider and the fraction of total revenue obtained. As the routing service providers (i.e., servers or routers in this context) compete, they may alter behavior in order to optimize one of the above properties. For example, a service provider may lower the price charged for its service, in order to increase the number of clients served. Our models are based on servers offering a routing service to clients within representative network topologies based on actual Internet sub-graphs. These models provide, a framework for evaluating competition in the Internet. We monitor key aspects of the service, as several variables are introduced into the models. The first variable is the fraction of client requests that will pay more for a better quality route. The remaining requests are normal client requests that are satisfied by the most economical route. The second variable is the fraction of servers who choose to lower service prices in order to maximize the number of client requests served. As this fraction increases, it is more likely that a server will lower the price. Finally, there are some resource constraints applied to the model, to increase the difficulty in providing a routing solution, i.e., to simulate a realistic scenario. We seek to understand the effect on the overall network, as service providers compete. In simple cases, we show that this competition could have a negative impact on the overall efficiency of a service. We show that the routing variety present in the larger models is unable to mask this tendency and the routing service performance is decreased due to competition.

Analysis of Inter-Domain Collaborative Routing: Provider Competition for Clients

Martin O. Nicholes,Chen-Nee Chuah,Shyhtsun Felix Wu,Biswanath Mukherjee 한국통신학회 2011 Journal of communications and networks Vol.13 No.5

Any server offering a routing service in the Internet would naturally be in competition for clients, and clients may need to utilize service from a specific server in order to achieve a desired result. We study the various properties of this competition,such as the fraction of route requests handled by a routing service provider and the fraction of total revenue obtained. As the routing service providers (i.e., servers or routers in this context) compete,they may alter behavior in order to optimize one of the above properties. For example, a service provider may lower the price charged for its service, in order to increase the number of clients served. Our models are based on servers offering a routing service to clients within representative network topologies based on actual Internet sub-graphs. These models provide a framework for evaluating competition in the Internet. We monitor key aspects of the service, as several variables are introduced into the models. The first variable is the fraction of client requests that will pay more for a better quality route. The remaining requests are normal client requests that are satisfied by the most economical route. The second variable is the fraction of servers who choose to lower service prices in order to maximize the number of client requests served. As this fraction increases, it is more likely that a server will lower the price. Finally, there are some resource constraints applied to the model, to increase the dif-ficulty in providing a routing solution, i.e., to simulate a realistic scenario. We seek to understand the effect on the overall network, as service providers compete. In simple cases, we show that this competition could have a negative impact on the overall efficiency of a service. We show that the routing variety present in the larger models is unable to mask this tendency and the routing service performance is decreased due to competition.

Drugs in Heart Failure

Nicholls, M. Gary Medical Publications Korea 1994 Medical Progress Vol.16 No.12

Photodermatoses

Nicholls, David Medical Publications Korea 1994 Medical Progress Vol.16 No.5

Bloodstream Infections and Frequency of Pretreatment Associated With Age and Hospitalization Status in Sub-Saharan Africa

Nichols, Chelsea,Cruz Espinoza, Ligia Maria,von Kalckreuth, Vera,Aaby, Peter,Ahmed El Tayeb, Muna,Ali, Mohammad,Aseffa, Abraham,Bjerregaard-Andersen, Morten,Breiman, Robert F.,Cosmas, Leonard,Crump, J Oxford University Press 2015 Clinical infectious diseases Vol.61 No.suppl4

<P><B><I>Background.</I></B> The clinical diagnosis of bacterial bloodstream infections (BSIs) in sub-Saharan Africa is routinely confused with malaria due to overlapping symptoms. The Typhoid Surveillance in Africa Program (TSAP) recruited febrile inpatients and outpatients of all ages using identical study procedures and enrollment criteria, thus providing an opportunity to assess disease etiology and pretreatment patterns among children and adults.</P><P><B><I>Methods.</I></B> Inpatients and outpatients of all ages with tympanic or axillary temperatures of ≥38.0 or ≥37.5°C, respectively, and inpatients only reporting fever within the previous 72 hours were eligible for recruitment. All recruited patients had one blood sample drawn and cultured for microorganisms. Data from 11 TSAP surveillance sites in nine different countries were used in the analysis. Bivariate analysis was used to compare frequencies of pretreatment and BSIs in febrile children (<15 years old) and adults (≥15 years old) in each country. Pooled Cochran Mantel–Haenszel odds ratios (ORs) were calculated for overall trends.</P><P><B><I>Results.</I></B> There was no significant difference in the odds of a culture-proven BSI between children and adults among inpatients or outpatients. Among both inpatients and outpatients, children had significantly higher odds of having a contaminated blood culture compared with adults. Using country-pooled data, child outpatients had 66% higher odds of having <I>Salmonella</I> Typhi in their bloodstream than adults (OR, 1.66; 95% confidence interval [CI], 1.01–2.73). Overall, inpatient children had 59% higher odds of pretreatment with analgesics in comparison to inpatient adults (OR, 1.59; 95% CI, 1.28–1.97).</P><P><B><I>Conclusions.</I></B> The proportion of patients with culture-proven BSIs in children compared with adults was similar across the TSAP study population; however, outpatient children were more likely to have <I>Salmonella</I> Typhi infections than outpatient adults. This finding points to the importance of including outpatient facilities in surveillance efforts, particularly for the surveillance of typhoid fever. Strategies to reduce contamination among pediatric blood cultures are needed across the continent to prevent the misdiagnosis of BSI cases in children.</P>

Government Policy Toward Open Source Software

Nichols, Albert L. 한국지적재산권학회(구 지적소유권학회) 2003 知的所有權法硏究 Vol.7 No.-

OSS is becoming more widely used Primarily for certain types of servers. There is no "market failure" in proprietary software highly competitive and innovative falling quality-adjusted prices. Best choice depends on specific needs, specific software available. No reason to impose a uniform choice or presumption as to which is superior. Future is sure to involve a mix of proprietary and open-source software. Policies should allow flexibility, innovation in all types of software.

Commentary from Southeast Asia : Heart Failure A Step-by-Step Guide

Nicholls, M. Gary Medical Publications Korea 1991 Medical Progress Vol.13 No.1

Designing Biomimetic Materials from Marine Organisms.

American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.1

<P>Two biomimetic design approaches that apply biological solutions to engineering problems are discussed. In the first case, motivation comes from an engineering problem and the key challenge is to find analogous biological functions and map them into engineering materials. We illustrate with an example of water pollution remediation through appropriate design of a biomimetic sponge. In the second case, a biological function is already known and the challenge is to identify the appropriate engineering problem. We demonstrate the biological approach with marine diatoms that control energy and materials at their surface providing inspiration for a number of engineering applications. In both cases, it is essential to select materials and structures at the nanoscale to control energy and materials flows at interfaces.</P>

Generalized growth curve models for longitudinal data in application to a randomized controlled trial

Nichole Andrews,Hyunkeun Ryan Cho 한국통계학회 2019 Journal of the Korean Statistical Society Vol.48 No.1

Growth curve analysis is beneficial in longitudinal studies, where the pattern of response variables measured repeatedly over time is of interest, yet unknown. In this article, we propose generalized growth curve models under a polynomial regression framework and offer a complete process that identifies the parsimonious growth curves for different groups of interest, as well as compares the curves. A higher order of a polynomial degree generally provides more flexible regression, yet it may suffer from the complicated and overfitted model in practice. Therefore, we employ the model selection procedure that chooses the optimal degree of a polynomial consistently. Consideration of a quadratic inference function (Qu et al., 2000) for estimation on regression parameters is addressed and estimation efficiency is improved by incorporating the within-subject correlation commonly existing in longitudinal data. In biomedical studies, it is of particular interest to compare multiple treatments and provide an effective one. We further conduct the hypothesis test that assesses the equality of the growth curves through an asymptotic chisquare test statistic. The proposed methodology is employed on a randomized controlled longitudinal dataset on depression. The effectiveness of our procedure is also confirmed with simulation studies.

인공두뇌 시스템 시대의 문화 작용

Nichols, Bill 한국예술종합학교 영상원 영상이론과 2002 영상이론 Vol.- No.1

컴퓨터는 객체 이상이다: 또한 컴퓨터는 자아와 환경에 대한 사고의 새로운 방식을 제안하고, 인간다움과 인간적인 세계에서 산다는 것의 의미를 구축하는 새로운 방식을 제안하는 도상이자 은유이다. 인공두뇌 시스템은 계산 능력이 있는 기계와 장치들의 전체 배열을 포함한다. 그런 시스템은 한계가 있을지라도 역동적인 지능지수를 가진다.