Exploring ant-based algorithms for gene expression data analysis

Objective: Recently, much research has been proposed using nature inspired algorithms to perform complex machine learning tasks. Ant colony optimization (ACO) is one such algorithm based on swarm intelligence and is derived from a model inspired by the collective foraging behavior of ants. Taking advantage of the ACO in traits such as self-organization and robustness, this paper investigates ant-based algorithms for gene expression data clustering and associative classification. Methods and material: An ant-based clustering (Ant-C) and an ant-based association rule mining (Ant-ARM) algorithms are proposed for gene expression data analysis. The proposed algorithms make use of the natural behavior of ants such as cooperation and adaptation to allow for a flexible robust search for a good candidate solution. Results: Ant-C has been tested on the three datasets selected from the Stanford Genomic Resource Database and achieved relatively high accuracy compared to other classical clustering methods. Ant-ARM has been tested on the acute lymphoblastic leukemia (ALL)/acute myeloid leukemia (AML) dataset and generated about 30 classification rules with high accuracy. Conclusions: Ant-C can generate optimal number of clusters without incorporating any other algorithms such as K-means or agglomerative hierarchical clustering. For associative classification, while a few of the well-known algorithms such as Apriori, FP-growth and Magnum Opus are unable to mine any association rules from the ALL/AML dataset within a reasonable period of time, Ant-ARM is able to extract associative classification rules.

Competition, competitive advantage, and clusters:the ideas of Michael Porter

Comprehensive coverage of all aspects of Michael Porter's works Contributions from leading authorities across the disciplines Contains response from Porter Harvard professor, Michael Porter has been one of the most influential figures in strategic management research over the last three decades. He infused a rigorous theoretical framework of industrial organization economics with the then still embryonic field of strategic management and elevated it to its current status as an academic discipline. Porter's outstanding career is also characterized by its cross-disciplinary nature. Following his most important work on strategic management, he then made a leap to the policy side and dealt with a completely different set of analytical units. More recently he has made a foray into inner city development, environmental regulations, and health care services. Throughout these explorations Porter has maintained his integrative approach, seeking a road that links management case studies and the general model building of mainstream economics. With expert contributors from a range of disciplines including strategic management, economic development, economic geography, and planning, this book assesses the contribution Michael Porter has made to these respective disciplines. It clarifies the sources of tension and controversy relating to all the major strands of Porter's work, and provides academics, students, and practitioners with a critical guide for the application of Porter's models. The book highlights that while many of the criticisms of Porter's ideas are valid, they are almost an inevitable outcome for a scholar who has sought to build bridges across wide disciplinary valleys. His work has provided others with a set of frameworks to explore in more depth the nature of competition, competitive advantage, and clusters from a range of vantage points.

Psychophysiological responses to pain identify reproducible human clusters

Pain is a ubiquitous yet highly variable experience. The psychophysiological and genetic factors responsible for this variability remain unresolved. We hypothesised the existence of distinct human pain clusters (PCs) composed of distinct psychophysiological and genetic profiles coupled with differences in the perception and the brain processing of pain. We studied 120 healthy subjects in whom the baseline personality and anxiety traits and the serotonin transporter-linked polymorphic region (5-HTTLPR) genotype were measured. Real-time autonomic nervous system parameters and serum cortisol were measured at baseline and after standardised visceral and somatic pain stimuli. Brain processing reactions to visceral pain were studied in 29 subjects using functional magnetic resonance imaging (fMRI). The reproducibility of the psychophysiological responses to pain was assessed at 1 year. In group analysis, visceral and somatic pain caused an expected increase in sympathetic and cortisol responses and activated the pain matrix according to fMRI studies. However, using cluster analysis, we found 2 reproducible PCs: at baseline, PC1 had higher neuroticism/anxiety scores (P ≤ 0.01); greater sympathetic tone (P < 0.05); and higher cortisol levels (P ≤ 0.001). During pain, less stimulus was tolerated (P ≤ 0.01), and there was an increase in parasympathetic tone (P ≤ 0.05). The 5-HTTLPR short allele was over-represented (P ≤ 0.005). PC2 had the converse profile at baseline and during pain. Brain activity differed (P ≤ 0.001); greater activity occurred in the left frontal cortex in PC1, whereas PC2 showed greater activity in the right medial/frontal cortex and right anterior insula. In health, 2 distinct reproducible PCs exist in humans. In the future, PC characterization may help to identify subjects at risk for developing chronic pain and may reduce variability in brain imaging studies. © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Self-sustained clusters and ergodicity breaking in spin models

Self-sustained spin clusters are analytically linked to ergodicity breaking in fully connected Ising and Sherrington-Kirkpatick (SK) models, relating the less understood spin space to the well understood state space. This correspondence is established through the absence of clusters in the paramagnetic phase, the presence of one dominant cluster in the Ising ferromagnet, and the formation of nontrivial clusters in SK spin glass. Yet unobserved phenomena are also revealed such as a first order phase transition in cluster sizes in the SK ferromagnet. The method could be adapted to investigate other spin models. © 2013 American Physical Society.

Service employee clusters in banking:exploring Ind's typology considering behaviour, commitment and attitude about leadership

Purpose: Ind suggests front line employees can be segmented according to their level of brand-supporting performance. His employee typology has not been empirically tested. The paper aims to explore front line employee performance in retail banking, and profile employee types. Design/methodology/approach: Attitudinal and demographic data from a sample of 404 front line service employees in a leading Irish bank informs a typology of service employees. Findings: Champions, Outsiders and Disruptors exist within retail banking. The authors provide an employee profile for each employee type. They found Champions amongst males, and older employees. The highest proportion of female employees surveyed were Outsiders. Disruptors were more likely to complain, and rated their performance lower than any other employee type. Contrary to extant literature, Disruptors were more likely to hold a permanent contract than other employee types. Originality/value: The authors augment the literature by providing insights about the profile of three employee types: Brand Champions, Outsiders and Disruptors. Moreover, the authors postulate the influence of leadership and commitment on each employee type. The cluster profiles raise important questions for hiring, training and rewarding front line banking employees. The authors also provide guidelines for managers to encourage Champions, and curtail Disruptors. © Emerald Group Publishing Limited.

Exploring clusters and their value as types of business networks in the agricultural sector

The undisputed link of the agricultural sector with regional economies, along with the increased competition, fosters agri-business companies to rethink their business philosophy and to transform from isolated firms to members of more extended business formations. The paper examines a particular type of business network, the cluster. It focuses on the concept of clusters and on cluster-based strategies in the context of agriculture. In particular, the paper explores the value of clusters by taking into consideration the particularities of the agricultural sector. Potential benefits and constraints of agri-business cluster development are also presented.

Psychophysiological responses to visceral and somatic pain in functional chest pain identify clinically relevant pain clusters

Background: Despite chronic pain being a feature of functional chest pain (FCP) its experience is variable. The factors responsible for this variability remain unresolved. We aimed to address these knowledge gaps, hypothesizing that the psychophysiological profiles of FCP patients will be distinct from healthy subjects. Methods: 20 Rome III defined FCP patients (nine males, mean age 38.7 years, range 28-59 years) and 20 healthy age-, sex-, and ethnicity-matched controls (nine males, mean 38.2 years, range 24-49) had anxiety, depression, and personality traits measured. Subjects had sympathetic and parasympathetic nervous system parameters measured at baseline and continuously thereafter. Subjects received standardized somatic (nail bed pressure) and visceral (esophageal balloon distension) stimuli to pain tolerance. Venous blood was sampled for cortisol at baseline, post somatic pain and post visceral pain. Key Results: Patients had higher neuroticism, state and trait anxiety, and depression scores but lower extroversion scores vs controls (all p < 0.005). Patients tolerated less somatic (p < 0.0001) and visceral stimulus (p = 0.009) and had a higher cortisol at baseline, and following pain (all p < 0.001). At baseline, patients had a higher sympathetic tone (p = 0.04), whereas in response to pain they increased their parasympathetic tone (p ≤ 0.008). The amalgamating the data, we identified two psychophysiologically distinct 'pain clusters'. Patients were overrepresented in the cluster characterized by high neuroticism, trait anxiety, baseline cortisol, pain hypersensitivity, and parasympathetic response to pain (all p < 0.03). Conclusions & Inferences: In future, such delineations in FCP populations may facilitate individualization of treatment based on psychophysiological profiling. © 2013 John Wiley & Sons Ltd.

A Statistical Approach for Multilingual Document Clustering and Topic Extraction from Clusters

2000 Mathematics Subject Classification: 62H30

Constructing 7-Clusters

ACM Computing Classification System (1998): G.2, G.4.

A multinacionális vállalatok szerepe a hazai klaszterekben (Roles of multinational enterprises in the Hungarian clusters)

A cikk azt a kérdést vizsgálja, hogy milyen szerepet töltenek be a multinacionális vállalatok leányvállalatai a hazai klaszterekben, milyen a kapcsolatuk a klasztertag kis- és középvállalatokkal többek között a közös innovációban, a tudásközvetítésben, a klaszterek reputációjának növelésében. A felderítő kutatás a témát a hazai klaszterfejlesztési program, a Pólus Program által életre hívott három, úgynevezett akkreditált klaszter menedzsereivel, a klasztertag multinacionális vállalatok (MNV-k) hazai leányvállalatainak képviselőivel és a klasztertag KKV-k vezetőivel készült interjúk alapján mutatja be. A téma relevanciáját a program által potenciálisan indukált együttműködési folyamatok adják, mivel a klaszterfejlesztési pályázati konstrukciók úgy lettek kialakítva, hogy a klasztertag KKV-knak érdemes legyen nagyvállalatot is bevonniuk a közös innovációs és kutatás-fejlesztési projektekbe. A kutatási eredmények alapján az MNV leányvállalatainak leginkább a globális trendek és standardok klaszterbeli elterjesztésében van meghatározó szerepük, illetve a KKV-k és leányvállalatok közötti üzleti kapcsolatok alakításában kiemelt szerepe van a klasztermenedzsment szervezet tevékenységének. / === / The paper focuses on the topic which deals with the role of subsidiaries of multinational companies (MNC’s) in Hungarian industrial clusters in the fields of common innovation, knowledge transfer, and increasing the cluster’s reputation. The findings of the paper are based on an explorative research. Interviews were made with cluster managers, representatives of MNC’s subsidiaries, leaders of small and medium size (SME’s) enterprises operating in three accredited clusters created by the Hungarian cluster development program, the Pole Program. The relevance of the topic is given by the Program, which has induced potential cooperation between MNC’s subsidiaries and domestic SME’s in cluster environment in a way so the members of the cluster – SME’s and subsidiaries – were driven to cooperate in common innovation and R+D projects. The author’s research results suggest that MNC’s subsidiaries in Hungarian clusters seem to play a key role in the dissemination of global industrial trends and standards between the cluster members. The national cluster management organization can also play a decisive role in shaping business relationship between MNC’s and SME’s.

Az exportteljesítmények és a hátterükben álló vállalati jellemzők elemzése (Export performance clusters of the Hungarian enterprises)

A tanulmány célja a Magyarországon működő exportáló vállalatok jellemzőinek feltárása volt a 2009-es vállalati versenyképességi felmérés alapján. Több tanulmány vizsgálta a vállalatok exportteljesítményét vállalati méret és tulajdonosi szerkezet szerinti bontásban, az elemzésben a szerző viszont ettől eltérő szemléletmódot alkalmazott. A vállalatok exportteljesítménye áll (exportértékesítés volumene, aránya, exportárbevétel változása, jövedelmezőség), a vállalati csoportképzés, klaszterelemzés középpontjában. Három jól elkülöníthető klasztert sikerült azonosítani: a jelentős exporthányaddal és folyamatos növekedéssel jellemezhető sikeres exportáló vállalatok csoportját, a stagnálással, s gyakran csökkenő exportértékesítéssel jellemezhető vállalatcsoportot, s végül a harmadik klasztert azok a jelenleg még alacsony export-ár bevétellel és alacsony exportaránnyal jellemezhető vállalatok képezték, melyekre a növekedés és a kiugróan magas jövedelmezőség volt a jellemző. Az elemzés egyediségét az adja, hogy a vállalati versenyképességi felmérés adatbázisa lehetővé tette a különböző exportteljesítmények hátterében álló működési jellemzők vizsgálatát, amelynek eredményeit a cikk bemutatja. Fő következtetésként megállapítható, hogy a sikeres exportáló vállalatok csoportja mindegyik jellemző szerint jobb működési jellemzőkkel rendelkezik a másik két csoporthoz viszonyítva. / === / The purpose of the paper is to reveal the main characteristics of the Hungarian export oriented firms. It is based on the Hungarian Competitiveness Research Survey 2009. 85% of enterprises were small or medium size in the sample. The aim of the analysis was to identify main factors and tendencies of the overall export performance. Several papers discussed the export activities of firms according to their size and ownership structure in Hungary. A different method was used here. The overall export performance (measured by volume, change, and share of export revenues, and firm profitability ratios) was put in the centre of cluster analysis. Three different clusters were identified. Firms in the firstcluster had significant export performance and growth rate. The second cluster was the group of stagnating firms and the third one contained those whose export performance was low but signaled growth with excellent profitability ratios. The uniqueness of the paper derived from the Competitiveness Research Survey because it provided an opportunity to analyse the connection between export performance and other management and operational characteristics of enterprises. The paper may induce futher research in exploring main enterprise level factors of export performance of the Hungarian firms.

A multinacionális vállalatok szerepe a hazai klaszterekben = The role of multinational companies in Hungarian clusters

A cikk azt a kérdést vizsgálja, hogy milyen szerepet töltenek be a multinacionális vállalatok leányvállalatai a hazai klaszterekben, milyen a kapcsolatuk a klasztertag kis- és középvállalatokkal többek között a közös innovációban, a tudásközvetítésben, a klaszterek reputációjának növelésében. A felderítő kutatás a témát a hazai klaszterfejlesztési program, a Pólus Program által életre hívott három, úgynevezett akkreditált klaszter menedzsereivel, a klasztertag multinacionális vállalatok (MNV-k) hazai leányvállalatainak képviselőivel és a klasztertag KKV-k vezetőivel készült interjúk alapján mutatja be. A téma relevanciáját a program által potenciálisan indukált együttműködési folyamatok adják, mivel a klaszterfejlesztési pályázati konstrukciók úgy lettek kialakítva, hogy a klasztertag KKV-knak érdemes legyen nagyvállalatot is bevonniuk a közös innovációs és kutatás-fejlesztési projektekbe. A kutatási eredmények alapján az MNV leányvállalatainak leginkább a globális trendek és standardok klaszterbeli elterjesztésében van meghatározó szerepük, illetve a KKV-k és leányvállalatok közötti üzleti kapcsolatok alakításában kiemelt szerepe van a klasztermenedzsment-szervezet tevékenységének. ----- Abstract: The paper focuses on the topic which deals with the role of subsidiaries of multinational companies (MNC’s) in Hungarian industrial clusters in the fields of common innovation, knowledge transfer, and increasing the cluster’s reputation. The findings of the paper are based on an explorative research. Interviews were made with cluster managers, representatives of MNC’s subsidiaries, leaders of small and medium size (SME’s) enterprises operating in three accredited clusters created by the Hungarian cluster development program, the Pole Program. The relevance of the topic is given by the Program, which has induced potential cooperation between MNC’s subsidiaries and domestic SME’s in cluster environment in a way so the members of the cluster – SME’s and subsidiaries – were driven to cooperate in common innovation and R+D projects. Our research results suggest that MNC’s subsidiaries in Hungarian clusters seem to play a key role in the dissemination of global industrial trends and standards between the cluster members. The national cluster management organization can also play a decisive role in shaping business relationship between MNC’s and SME’s.

A japán társadalmi klaszterek szerepe és kihasználásának lehetőségei a versenyképesség megtartásában = The Role of Clusters in Japan’s Competitiveness

Az amerikai történelemben a paradigmaváltások meglehetősen nagyszabású és alapvető hatásokkal jártak, míg Japánban mintha hosszú távon is a Tudományos vezetés (gyártás-orientált) paradigmájánál maradtak volna, mely aztán módosult valamennyit a többi paradigma megjelenésének hatására. A tanulmány ebből az elméleti megállapításból kiindulva vizsgálja meg mind szakirodalmi alapon, mind egy kérdőíves kutatás segítségével, a japán társadalom „reakcióidejét”: attitűdjeit a változással, az alkalmazkodással szemben. Alapfeltételezése, hogy a tartós versenyképesség fenntartásához elengedhetetlen a külső körülményekhez való folyamatos alkalmazkodás, ami időről időre a múlt gyakorlatainak megkérdőjelezését eredményezi. Rövid elemzésünk azon az előfeltevésen alapult, hogy egy vagy több, a számát és / vagy társadalmi befolyását tekintve jelentős társadalmi csoport továbbra is erősen támogatja a hagyományos japán vezetési gyakorlatot. A hipotézist sikeresen bebizonyítottuk: a hagyományos menedzsmentet szignifikánsan támogatta két olyan klaszter, melyek száma jelentősen meghaladta a panel fennmaradó részét és amelyek nagyobb fokú társadalmi befolyást is képviseltek. Megállapítottuk, hogy a régi rendszert valószínűleg azok a rangidős japán férfiak támogatják, akik állandó dolgozóként vagy vezetőként dolgoznak meglehetősen nagy vállalatoknál, hosszú távú foglalkoztatásban. Egy másik csoportot is azonosítottunk az előzővel szemben, mely fiatalabb tagokból áll, változatosabb és magasabb iskolai végzettség jellemzi. Még nem egyértelmű, hogy a második csoport tagjai életkoruk előrehaladtával betagozódnak majd a japán rendszerbe és vállalatokba, ahogy az a múltban is történt, vagy továbbra is küzdenek majd a hagyományos módszerek ellen. Mindenesetre célszerűnek látszik az eredmények alapján a kutatás továbbgondolása és magyarországi megvalósítása is, ami által a magyar gazdasági és kormányzati elit a versenyképesség szempontjából értékes információkhoz juthat, nevezetesen az elavultnak számító gyakorlatok beazonosításán és az ennek fennmaradásáért felelős csoportok leírásán keresztül. _________ In the American history, change between paradigms implied rather large-scale and deep effects, whereas the Japanese seem to keep the focus on the Scientific Management (or production-oriented) paradigm which was only party altered by the others (HR, etc.). Based on this affirmation, our study examines the reactivity of Japanese society both in a theoretical and in a practical sense. We assumed first that continuous adaptation to the external conditions is an essential element of long-term competitiveness, which implies the regular questioning of old management practices. We presumed that one or several group(s) of people is (are) still strongly supporting traditional Japanese management practices and they must be important in terms of number and/or social influence. We have found evidence for our hypothesis: two significantly supportive clusters which largely outnumbered the rest of the panel and represented a higher level of social influence as well. We stated that the old system is probably supported by senior Japanese males who work as regular (core) employees or managers in rather large companies and enjoy long-term employment. Another group was also identified as a contrast to the former one, with younger members, more diversity and a higher level of education. As they grow older, the second group may become socialized into the Japanese system as happened in the past, or continue to reject traditional methods. Based on our observations, it seems useful to broaden the focus of our research and carry out a similar study in Hungary as well. This will bring valuable information on competitiveness to the business and political elite, enabling them to identify inefficient old practices and to better target the groups responsible for maintaining those practices.