Skip to main content Accessibility help

We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.

Close cookie message
×
  1. Home
  2. Search

Refine search

Refine search

Access:
Content type:
Publication date:
Apply   From and To filters
Subject: Show more
Journals Show more
Publishers: Show more
Societies Show more
Series: Show more
Collections: Show more

Actions for selected content:

Select all | Deselect all
  • View selected items
  • Export citations
  • Download PDF (zip)
  • Save to Kindle
  • Save to Dropbox
  • Save to Google Drive

Save Search

You can save your searches here and later view and run them again in "My saved searches".

Please provide a title, maximum of 40 characters.
Cancel
×

32 results

Page 1 of 2

  • NOTES ON SACKS’ SPLITTING THEOREM

  • Part of
  • KLAUS AMBOS-SPIES, ROD G. DOWNEY, MARTIN MONATH, KENG MENG NG
  • Journal:
    The Journal of Symbolic Logic , First View
    Published online by Cambridge University Press:
    26 October 2023, pp. 1-30
    • Article
      • You have access
      • Open access
    • PDF
    • HTML
    • Export citation

  • We explore the complexity of Sacks’ Splitting Theorem in terms of the mind change functions associated with the members of the splits. We prove that, for any c.e. set A, there are low computably enumerable sets $A_0\sqcup A_1=A$ splitting A with $A_0$ and $A_1$ both totally $\omega ^2$-c.a. in terms of the Downey–Greenberg hierarchy, and this result cannot be improved to totally $\omega $-c.a. as shown in [9]. We also show that if cone avoidance is added then there is no level below $\varepsilon _0$ which can be used to characterize the complexity of $A_1$ and $A_2$.

  • Computable soft separation axioms

  • S. M. Elsayed, Keng Meng Ng
  • Journal:
    Mathematical Structures in Computer Science / Volume 33 / Issue 9 / October 2023
    Published online by Cambridge University Press:
    12 October 2023, pp. 781-808

  • Soft sets were introduced as a means to study objects that are not defined in an absolute way and have found applications in numerous areas of mathematics, decision theory, and in statistical applications. Soft topological spaces were first considered in Shabir and Naz ((2011). Computers & Mathematics with Applications 61 (7) 1786–1799) and soft separation axioms for soft topological spaces were studied in El-Shafei et al. ((2018). Filomat 32 (13) 4755–4771), El-Shafei and Al-Shami ((2020). Computational and Applied Mathematics 39 (3) 1–17), Al-shami ((2021). Mathematical Problems in Engineering 2021). In this paper, we introduce the effective versions of soft separation axioms. Specifically, we focus our attention on computable u-soft and computable p-soft separation axioms and investigate various relations between them. We also compare the effective and classical versions of these soft separation axioms.

  • COMPUTABLE TOPOLOGICAL GROUPS

  • Part of
  • HEER TERN KOH, ALEXANDER G. MELNIKOV, KENG MENG NG
  • Journal:
    The Journal of Symbolic Logic , First View
    Published online by Cambridge University Press:
    18 September 2023, pp. 1-33
    • Article
      • You have access
      • Open access
    • PDF
    • HTML
    • Export citation

  • We investigate what it means for a (Hausdorff, second-countable) topological group to be computable. We compare several potential definitions based on classical notions in the literature. We relate these notions with the well-established definitions of effective presentability for discrete and profinite groups, and compare our results with similar results in computable topology.

  • ON THE C.E. DEGREES REALIZABLE IN $\Pi ^0_1$ CLASSES

  • Part of
  • BARBARA F. CSIMA, ROD DOWNEY, KENG MENG NG
  • Journal:
    The Journal of Symbolic Logic , First View
    Published online by Cambridge University Press:
    24 April 2023, pp. 1-26
    • Article
      • You have access
      • Open access
    • PDF
    • HTML
    • Export citation

  • We study for each computably bounded $\Pi ^0_1$ class P the set of degrees of c.e. paths in P. We show, amongst other results, that for every c.e. degree a there is a perfect $\Pi ^0_1$ class where all c.e. members have degree a. We also show that every $\Pi ^0_1$ set of c.e. indices is realized in some perfect $\Pi ^0_1$ class, and classify the sets of c.e. degrees which can be realized in some $\Pi ^0_1$ class as exactly those with a computable representation.

  • The Elderly Nutritional Index for Geriatric Malnutrition Assessment (ENIGMA): concurrent, construct and predictive validity in an external evaluation cohort of community-dwelling older persons

  • Tze-Pin Ng, Shan Hai, Qi Gao, Xinyi Gwee, Denise Qian Ling Chua, Philip Yap, Keng Bee Yap, Shiou Liang Wee
  • Journal:
    British Journal of Nutrition / Volume 128 / Issue 3 / 14 August 2022
    Published online by Cambridge University Press:
    06 September 2021, pp. 509-520
    Print publication:
    14 August 2022
    • Article
      • You have access
    • PDF
    • HTML
    • Export citation

  • We previously developed a malnutrition risk index, the Elderly Nutritional Index for Geriatric Malnutrition Assessment (ENIGMA) with good predictive accuracy for mortality risk in an original population cohort (SLAS1). Herein, we further evaluate the concurrent and predictive validity of the ENIGMA construct in an external validation cohort (SLAS-2) of 2824 community-dwelling older adults aged 55+ years. They were assessed on the ENIGMA index, Mini Nutritional Assessment-Short Form (MNA-SF) and the Geriatric Nutritional Risk Index (GNRI), known correlates of malnutrition, and baseline and follow-up functional dependency and 10-year mortality risk. Higher ENIGMA risk categories were significantly associated (P < 0·001) with lower education, living alone, smoking, low physical activity, BMI < 18·5 kg/m2, poorer muscle strength and functional mobility, exhaustion, physical frailty, homocysteine, glomerular filtration rate, Hb, red and white blood cell counts, platelets, systemic inflammation indexes, metabolic syndrome, CVD, cognitive impairment and depressive symptoms (Geriatric Depression Scale ≥ 5). ENIGMA scores showed statistically significant (P < 0·001) correlations but low-to-moderate concordance with MNA-SF (r = 0·148, agreement = 45·9 %, kappa = 0·085) and GNRI scores (r = 0·156, agreement = 45·8 %, kappa = 0·096). Controlling for known correlates of malnutrition, only high-risk ENIGMA among the indexes significantly predicted baseline functional dependency (OR = 1·64, 95 % CI 1·01, 2·65) and mortality (hazard ratio = 1·65 (95 % CI 1·04, 2·62). ENIGMA marginally out-performed MNA-SF and GNRI in predicting baseline functional dependency (AUC: 0·625 v. 0·584 v. 0·526), follow-up functional dependency (AUC: 0·594 v. 0·525 v. 0·479) and 10-year mortality risk (AUC: 0·641 v. 0·596 v. 0·595). The concurrent and predictive validity of the ENIGMA construct is replicated in an external evaluation study of community-dwelling older persons.

  • PUNCTUAL CATEGORICITY AND UNIVERSALITY

  • Part of
  • ROD DOWNEY, NOAM GREENBERG, ALEXANDER MELNIKOV, KENG MENG NG, DANIEL TURETSKY
  • Journal:
    The Journal of Symbolic Logic / Volume 85 / Issue 4 / December 2020
    Published online by Cambridge University Press:
    22 October 2020, pp. 1427-1466
    Print publication:
    December 2020

  • We describe punctual categoricity in several natural classes, including binary relational structures and mono-unary functional structures. We prove that every punctually categorical structure in a finite unary language is ${\text {PA}}(0')$-categorical, and we show that this upper bound is tight. We also construct an example of a punctually categorical structure whose degree of categoricity is $0''$. We also prove that, with a bit of work, the latter result can be pushed beyond $\Delta ^1_1$, thus showing that punctually categorical structures can possess arbitrarily complex automorphism orbits.

    As a consequence, it follows that binary relational structures and unary structures are not universal with respect to primitive recursive interpretations; equivalently, in these classes every rich enough interpretation technique must necessarily involve unbounded existential quantification or infinite disjunction. In contrast, it is well-known that both classes are universal for Turing computability.

  • 15 - Johor Bahru’s Urban Transformation: Authority and Agency Revisited

  • Edited by Francis E. Hutchinson, Serina Rahman
  • Book:
    Johor
    Published by:
    ISEAS–Yusof Ishak Institute
    Published online:
    24 November 2020
    Print publication:
    01 September 2020, pp 407-423

  • Summary

    INTRODUCTION

    Johor, West Malaysia's southernmost state, has undergone a tremendous urban transformation over the last decade. Its strategic location, adjacent to Singapore, has contributed to escalating development and rising land values. The state offers many opportunities for investors; its rapid urban transformation is closely associated with the establishment of Iskandar Malaysia, a special economic zone (SEZ) that was officially launched in 2006. Initially 2,217 square kilometres in area, Iskandar Malaysia was singled out as the highest-impact development project in the Ninth Malaysia Plan (2006–10). Modelled ostensibly after the Pearl River Delta Economic Zone, Iskandar Malaysia seeks to maximize spillover effects for business and industry from land-scarce Singapore as well as other destinations. In its wake, the SEZ brought an unprecedented building boom and speculation in the international property sector.

    Malaysia has a long-standing history of land reform and redistribution. From independence, land reform was deemed critical for poverty reduction, as seen through large-scale initiatives such as the Federal Land Development Authority (FELDA), which sought to create livelihoods for poor rural families with little or no assets (Henley 2015).

    However, while land management is, according to the Constitution, a state government responsibility, national-level needs and initiatives have led to federal government encroachment in these and many other areas (Hutchinson 2014). As land remains a premium asset for the both levels of government, the process of sourcing for and developing land can become contested.

    Johor's land redistribution policy and property development practices have undergone profound changes over the last ten years. The state government has opened up Johor Bahru's high-end residential market to both local non-bumiputra enterprises and foreign developers. There are about forty ongoing or recently completed property projects in Johor. These projects attributed to 42 per cent of the stock of 702,101 new houses in the state. From 2007 to 2016, Johor recorded a total sale of investment properties of more than US$8.1 billion. In 2013, over 76.4 per cent of investment properties (mostly residential) were purchased by foreign investors (Savills World Research Malaysia 2015).

    This chapter aims to understand and reflect on Johor Bahru's fast-changing urban environment. It intends to broaden the study of land reform by considering how government-linked companies, bureaucratic elite and foreign developers have acted together to reshape land development practices in contemporary Johor.

  • 16 - Housing Policy in Johor: Trends and Prospects

  • Edited by Francis E. Hutchinson, Serina Rahman
  • Book:
    Johor
    Published by:
    ISEAS–Yusof Ishak Institute
    Published online:
    24 November 2020
    Print publication:
    01 September 2020, pp 424-446

  • Summary

    INTRODUCTION

    Housing development in Johor has undergone profound transformation over the last few decades. High-rise apartments are now a common sight in downtown Johor Bahru. Luxury enclaves, complete with gated security and leisure facilities, encroach on waterfront land along the Tebrau Strait. Foreign developers have built new townships on reclaimed land, exhorting international buyers to invest their future in the project as well as the rest of Johor. This chapter will examine housing policies and development strategies in Johor, especially those related to the establishment of Iskandar Malaysia (IM). The history of Johor's housing trends and its prospects in the near and medium term will also be analysed. This chapter argues that the launch of IM had a far-reaching impact not only on housing stock, but also on property ownership practices in Johor.

    There are three main sections in the chapter. The first section focuses on housing provision and policy in Johor with an analysis of statistical data such as housing stock and distribution of income. The section will ascertain the manner in which the state government manages Johor's housing blueprint. It also discusses associated opportunities and challenges faced by the state government and housing developers, both private and government-linked corporations (GLCs).

    The following section illustrates overall practices of housing development in Malaysia since independence. This section considers how housing is managed under national development plans, by-laws, and policies. We examine the major agendas and aspirations for housing in Malaysia and how housing provisions is carried out at both federal and state levels. We also look at the roles of the different layers of government and private developers in housing provision and how these roles evolved in tandem with global trends of economic liberalization. We then take a closer look at housing trends in southern Johor over the last decade, especially those related to the implementation of Iskandar Malaysia.

    Acknowledging the rise of Iskandar Malaysia as a regional business hub and its profound impact on Johor, the third section adopts a grounded approach in presenting two case studies to make sense of the housing situation in the state. These projects are Medini Iskandar Malaysia (Medini) and Forest City, two of the largest housing projects within Iskandar Malaysia. It will also reflect on the rather different business models, architectural concepts, and development strategies of both projects.

  • AUTOMATIC AND POLYNOMIAL-TIME ALGEBRAIC STRUCTURES

  • NIKOLAY BAZHENOV, MATTHEW HARRISON-TRAINOR, ISKANDER KALIMULLIN, ALEXANDER MELNIKOV, KENG MENG NG
  • Journal:
    The Journal of Symbolic Logic / Volume 84 / Issue 4 / December 2019
    Published online by Cambridge University Press:
    29 April 2019, pp. 1630-1669
    Print publication:
    December 2019

  • A structure is automatic if its domain, functions, and relations are all regular languages. Using the fact that every automatic structure is decidable, in the literature many decision problems have been solved by giving an automatic presentation of a particular structure. Khoussainov and Nerode asked whether there is some way to tell whether a structure has, or does not have, an automatic presentation. We answer this question by showing that the set of Turing machines that represent automata-presentable structures is ${\rm{\Sigma }}_1^1 $-complete. We also use similar methods to show that there is no reasonable characterisation of the structures with a polynomial-time presentation in the sense of Nerode and Remmel.

Beneath the Veneer
  • The Political Economy of Housing in Iskandar Malaysia, Johor
  • Keng Khoon Ng, Guanie Lim
  • Published by:
    ISEAS–Yusof Ishak Institute
    Published online:
    12 March 2019
    Print publication:
    18 September 2017
  • The rise of Iskandar Malaysia as a regional hub has profoundly altered the domestic landscape, generating a knock-on effect on Johor's housing development, both economically and politically. Housing policy and development in Johor, as illustrated in the formation of Iskandar Malaysia, is riddled with conflict along two dimensions — "bumiputra versus non-bumiputra" and "federal government versus state government". The first one is entangled with international real estate development and foreign investment, while the latter has more to do with the rise of sub-national autonomy in Johor. Particularly in southern Johor, housing policy has increasingly been influenced by foreign investment through implementations of mega projects (e.g., Forest City). These mega housing projects not only boost the state's coffers, but also change the way housing is produced, financed and governed. Given the importance of sub-national governments in many large-scale housing projects in Iskandar Malaysia, the changing political conditions urge us to rethink the long-standing practice of national-centric development policy in Malaysia. Taking housing as a point of departure, the timing is ripe to revisit the role of state government in policy-making and urban governance.

  • Foreword

  • Keng Khoon Ng, Guanie Lim
  • Book:
    Beneath the Veneer
    Published by:
    ISEAS–Yusof Ishak Institute
    Published online:
    12 March 2019
    Print publication:
    18 September 2017, pp v-v

  • Summary

    The economic, political, strategic and cultural dynamism in Southeast Asia has gained added relevance in recent years with the spectacular rise of giant economies in East and South Asia. This has drawn greater attention to the region and to the enhanced role it now plays in international relations and global economics.

    The sustained effort made by Southeast Asian nations since 1967 towards a peaceful and gradual integration of their economies has had indubitable success, and perhaps as a consequence of this, most of these countries are undergoing deep political and social changes domestically and are constructing innovative solutions to meet new international challenges. Big Power tensions continue to be played out in the neighbourhood despite the tradition of neutrality exercised by the Association of Southeast Asian Nations (ASEAN).

    The Trends in Southeast Asia series acts as a platform for serious analyses by selected authors who are experts in their fields. It is aimed at encouraging policy makers and scholars to contemplate the diversity and dynamism of this exciting region.

  • Beneath the Veneer: The Political Economy of Housing in Iskandar Malaysia, Johor

  • Keng Khoon Ng, Guanie Lim
  • Book:
    Beneath the Veneer
    Published by:
    ISEAS–Yusof Ishak Institute
    Published online:
    12 March 2019
    Print publication:
    18 September 2017, pp vi-viii

  • Summary

    EXECUTIVE SUMMARY

  • • The rise of Iskandar Malaysia as a regional hub has profoundly altered the domestic landscape, generating a knock-on effect on Johor's housing development, both economically and politically.

  • • Housing policy and development in Johor, as illustrated in the formation of Iskandar Malaysia, is riddled with conflict along two dimensions — “bumiputra versus non-bumiputra” and “federal government versus state government”. The first one is entangled with international real estate development and foreign investment, while the latter has more to do with the rise of sub-national autonomy in Johor.

  • • Particularly in southern Johor, housing policy has increasingly been influenced by foreign investment through implementations of mega projects (e.g., Forest City). These mega housing projects not only boost the state's coffers, but also change the way housing is produced, financed and governed.

  • • Given the importance of sub-national governments in many large-scale housing projects in Iskandar Malaysia, the changing political conditions urge us to rethink the long-standing practice of national-centric development policy in Malaysia. Taking housing as a point of departure, the timing is ripe to revisit the role of state government in policy-making and urban governance.

  • Beneath the Veneer: The Political Economy of Housing in Iskandar Malaysia, Johor

  • Keng Khoon Ng, Guanie Lim
  • Book:
    Beneath the Veneer
    Published by:
    ISEAS–Yusof Ishak Institute
    Published online:
    12 March 2019
    Print publication:
    18 September 2017, pp 1-28

  • Summary

    Housing development in Johor has undergone profound transformation in the last decades. High-rise apartments are now a common sight in the downtown area close to Singapore. Luxurious enclaves, complete with gated security and leisure facilities, encroach on waterfront land along the Straits of Johor. Foreign developers build new townships on reclaimed land, exhorting international buyers to invest their future in these projects as well as the rest of Johor.

    This paper attempts to explore the political economy underwriting such development, analysing the housing policies and development goals of both the Malaysian government as well as its Johorean counterpart. It does so by focusing on Iskandar Malaysia, a special economic zone (SEZ) earmarked as a high-impact project since 2006 by Malaysia's economic planners. Despite some commercial success, this paper argues that Iskandar Malaysia is bogged down by tensions along two dimensions: bumiputra versus non-bumiputra interests; and federal government versus state government priorities. The paper unpacks such tensions by analysing the case of Forest City, one of the most high-profile projects in Iskandar Malaysia in recent years.

    The paper begins with an analysis of Johor's housing situation. It examines statistical data from the relevant authorities to make sense of the demand and supply of houses in the state. The paper then focuses on Iskandar Malaysia, unearthing its origins and subsequent growth trajectory. In particular, it sheds light on the tension between the federal government and the Johor government in managing the development of Iskandar Malaysia. The next section analyses the changes and deviations of Johor's housing policy. In particular, it investigates the provision mechanisms of low-cost housing. A probe into such issues enables a better understanding of the state's long-term housing challenges and solutions. Thereafter, a case study of Forest City is presented for its utility in underlining the inherent conflict of housing development in Johor. The paper concludes with a summary of the main arguments.

    OVERVIEW OF HOUSING DEVELOPMENT IN JOHOR

    Johor is a state located at the southern end of Peninsular Malaysia. With a total land area of 19,016 km and total population of 3.66 million, Johor is the fifth largest and second largest state respectively in physical and population terms (Department of Statistics 2017). According to the Town and Country Planning Department of Johor (2017), the state's population will reach 6.06 million by 2030.

  • FINITARY REDUCIBILITY ON EQUIVALENCE RELATIONS

  • RUSSELL MILLER, KENG MENG NG
  • Journal:
    The Journal of Symbolic Logic / Volume 81 / Issue 4 / December 2016
    Published online by Cambridge University Press:
    01 December 2016, pp. 1225-1254
    Print publication:
    December 2016
    • Article
      • You have access
    • PDF
    • Export citation

  • We introduce the notion of finitary computable reducibility on equivalence relations on the domain ω. This is a weakening of the usual notion of computable reducibility, and we show it to be distinct in several ways. In particular, whereas no equivalence relation can be ${\rm{\Pi }}_{n + 2}^0$-complete under computable reducibility, we show that, for every n, there does exist a natural equivalence relation which is ${\rm{\Pi }}_{n + 2}^0$-complete under finitary reducibility. We also show that our hierarchy of finitary reducibilities does not collapse, and illustrate how it sharpens certain known results. Along the way, we present several new results which use computable reducibility to establish the complexity of various naturally defined equivalence relations in the arithmetical hierarchy.

  • COMPLEXITY OF EQUIVALENCE RELATIONS AND PREORDERS FROM COMPUTABILITY THEORY

  • EGOR IANOVSKI, RUSSELL MILLER, KENG MENG NG, ANDRÉ NIES
  • Journal:
    The Journal of Symbolic Logic / Volume 79 / Issue 3 / September 2014
    Published online by Cambridge University Press:
    18 August 2014, pp. 859-881
    Print publication:
    September 2014

  • We study the relative complexity of equivalence relations and preorders from computability theory and complexity theory. Given binary relations R, S, a componentwise reducibility is defined by

    R ≤ S ⇔ ∃f ∀x, y [x R y ↔ f (x) S f (y)].

    Here, f is taken from a suitable class of effective functions. For us the relations will be on natural numbers, and f must be computable. We show that there is a ${\rm{\Pi }}_1^0$-complete equivalence relation, but no ${\rm{\Pi }}_k^0$-complete for k ≥ 2. We show that ${\rm{\Sigma }}_k^0$ preorders arising naturally in the above-mentioned areas are ${\rm{\Sigma }}_k^0$-complete. This includes polynomial time m-reducibility on exponential time sets, which is ${\rm{\Sigma }}_2^0$, almost inclusion on r.e. sets, which is ${\rm{\Sigma }}_3^0$, and Turing reducibility on r.e. sets, which is ${\rm{\Sigma }}_4^0$.

Page 1 of 2