On the Finite-Time Complexity and Practical Computation of Approximate Stationarity Concepts of Lipschitz Functions

We report a practical finite-time algorithmic scheme to compute approximately stationary points for nonconvex nonsmooth Lipschitz functions. In particular, we are interested in two kinds of approximate stationarity notions for nonconvex nonsmooth problems, i.e., Goldstein approximate stationarity (GAS) and near-approximate stationarity (NAS). For GAS, our scheme removes the unrealistic subgradient selection oracle assumption in (Zhang et al., 2020, Assumption 1) and computes GAS with the same finite-time complexity. For NAS, Davis & Drusvyatskiy (2019) showed that $\rho$-weakly convex functions admit finite-time computation, while Tian & So (2021) provided the matching impossibility results of dimension-free finite-time complexity for first-order methods. Complement to these developments, in this paper, we isolate a new class of functions that could be Clarke irregular (and thus not weakly convex anymore) and show that our new algorithmic scheme can compute NAS points for functions in that class within finite time. To demonstrate the wide applicability of our new theoretical framework, we show that $\rho$-margin SVM, $1$-layer, and $2$-layer ReLU neural networks, all being Clarke irregular, satisfy our new conditions.Comment: 20 pages, 3 figures, ICML 202

Characteristics and strategies of a consistently profitable proprietary day trader at bursa Malaysia / Saw Imm Song, Ei Yet Chu and Tian So Lai

Proprietary day trading is relatively new in Malaysia. This study looks into the background characteristics, strategies, behaviour of an above average proprietary trader and factors that determined her success. Recent literature in the developed markets found that the majority of the day traders failed in the first year of trading. Few studies have looked into the winning characteristics and strategies of the traders. Contrary to the findings on failed traders, who traded actively, speculatively, and to their detriment, this case study found that a successful trader on the other hand is highly attentive and disciplined. On average the trader had executed approximately 20 counters per day for  about 100 transactions. More than 50% of the roundtrips transactions were completed within half an hour and 70% were completed within 2 hours.  The trader was most active in the morning for buy transactions and the majority of the roundtrips were completed in the afternoon. The trader usually holds large positions only for shorter periods to minimise huge losses and disposition effect.  It was evident that the trader employs scalping strategies that she profits from very short run and small movement of prices rather than employing fundamental analysis which requires longer term investment horizon. If the trader made profits in the morning, the likelihood is the trader will be more aggressive in the afternoon trades. The regression results reveal that factors that significantly explained the profitability of the trader were the transaction values and the time entering the trades. Market sentiment and duration of holding time do not significantly explain the profitability made by the trader. It shows that in a bullish market, the trader tended to trade more transactions; however that does not contribute significantly to the profits made

Characteristics and strategies of a consistently profitable proprietory day trader at bursa Malaysia

Proprietary day trading is relatively new in Malaysia. This study looks into the background characteristics, strategies, and behaviour of an above average proprietary trader and factors that determine her success. Recent literature in the developed markets found that a majority of day traders fail in the first year of trading. Few studies have looked into the winning characteristics and strategies of traders. Contrary to the findings on failed traders, who trade actively, speculatively, and to their detriment, this case study found that a successful trader on the other hand is highly attentive and disciplined. On average the trader had executed approximately 20 counters per day for about 100 transactions. More than 50% of the roundtrip transactions were completed within half an hour and 70% were completed within 2 hours. The trader was most active in the morning for buy transactions and the majority of the roundtrips were completed in the afternoon. The trader usually holds large positions only for shorter periods to minimise huge losses and the disposition effect. It is evident that the trader employs scalping strategies that she profits from in a very short run and small movement of prices rather than employing fundamental analysis which requires a longer-term investment horizon. If the trader made profits in the morning, the likelihood is the trader will be more aggressive in the afternoon trades. The regression results reveal that factors that significantly explain the profitability of the trader were the transaction values and the time of entering the trades. Market sentiment and duration of holding time do not significantly explain the profitability made by the trader. It shows that in a bullish market, the trader tends to trade more transactions; however, that does not contribute significantly to the profits made

Managing migrant worker's job satisfaction: A study on a manufacturing company in Malaysia

The purpose of this study is to examine and gain a better understanding of the impact of human resource practices on migrant workers' job satisfaction in a manufacturing company. Ninety migrant workers consist of 52 Bangladeshi and 38 Nepalese workers participated in this study. Data was obtained using questionnaires and analyzed. Statistical analysis using regression analysis found the research model has a weak predictive power on migrant workers' job satisfaction. Among the independent variables, only compensation was found to have an impact on migrant workers job satisfaction. T-test results also revealed that Nepalese workers and migrant workers who possess only primary education have higher job satisfaction

Financial constraints and corporate governance in family controlled firms in Malaysia

The hypothesis of financial constraints suggest that firms be denied profitable investment due to inaccessible to external capital markers as debt and equity financing are no longer perfect substitution after firms utilise internal capital. In view of reducing investments during global financial crisis in 2008-2009, the study investigates 157 firms whether they face the issues of financial constraint in Malaysia. In general, non-family firms rely heavily on external debt market while family controlled firms utilising internal cash and reducing their dependence on debt market for their investments. However, the presence of CEO duality does not exaggerate the problem of financial constraints firms, but rather lead family firms to become stagnant in their investments. Independent directors appear to be ineffective in governance family firms for issuing financing for investment. Apparently, their presence in family firms reduce firms’ investment opportunities either through internal cash flow and external debt financing, which could reduce shareholders’ value in long-term

Corporate governance and financial constraints in family controlled firms: Evidence from Malaysia

The hypothesis of financial constraints suggests that firms will be denied profitable investment due to inaccessible to external capital markets as debt and equity financing are no longer perfect substitutions after firms utilize internal capital. In view of reduced investments during global financial crisis in 2008-2009, the study investigates 157 firms, whether they face the issues of financial constraints in Malaysia. In general, non-family firms rely heavily on the external debt market while family controlled firms utilizing internal cash and reducing their dependence on debt market for their investments, confirming financial constraints in family firms. However, the presence of CEO duality does not exaggerate the problem of financial constraints, but rather leads family firms to become stagnant in their investments. Independent directors appear to be ineffective in governing family firms in issuing finances for investment. Apparently, their presence in family firms reduces firms’ investment opportunities either through internal cash and external debt financing, which could reduce shareholders’ value in the long-term

Impacts of foreign currency exposure on Malaysia’s firm value: Firm value, hedging and corporate governance perspectives

Purpose: This study examines and assesses the relationship between foreign currency exposures in terms of account receivable and payable and firm value of Malaysia firms. Design/methodology/approach: The study takes the balance sheet approach where a total sample firm of 148 Malaysia public reported their foreign currencies exposure from 2006 to 2013. Foreign currencies exposures in USD and SGD are regressed on firm value as these are most reported foreign currencies exposures. The study examines the issues from the perspective of firms’ size, hedging strategy, and corporate governance perspective. Findings: The findings suggest that Malaysia firms do not manage their exposures to USD well, both account payable and receivable. Large firms are also not well equipped to improve firm value when it is highly exposed, especially to USD as compared to SGD. Hedging strategies are not effective in the country as it does not significantly improve firm value. However, the presence of independent directors and large shareholders assert some monitoring effects on USD payables exposures and SGD receivable exposures, which lead to a positive firm value. Research limitations/implications: Corporate governance could substitute the role of hedging strategy in managing foreign currencies exposures. The research is hindered by the limitation information on hedging reported in annual reports. Practical implications: The study suggests the role of corporate governance is essential in various perspective of financial management. Large shareholders and independent directors could assert an effective role in monitoring risk as their controlling stake increases. In terms of USD exposures, which is more volatile, Malaysia firms are not managing USD exposures well and lead to declining of firm value. Malaysia firms should be more prepared financially and strategically when dealing with USD exposure, which is more volatile. Originality/value: The study applies balance sheet approach based on account payable and receivable on currencies exposure. Various perspective, especially issues on corporate governance is new when approaching the issues of foreign currencies exposures, especially in the contexts of emerging economy

Development of a new mechano-chemical model in boundary lubrication

A newly developed tribochemical model based on thermodynamics of interfaces and kinetics of tribochemical reactions is implemented in a contact mechanics simulation and the results are validated against experimental results. The model considers both mechanical and thermal activation of tribochemical reactions instead of former thermal activation theories. The model considers tribofilm removal and is able to capture the tribofilm behaviour during the experiment. The aim of this work is to implement tribochemistry into deterministic modelling of boundary lubrication and study the effect of tribofilms in reducing friction or wear. A new contact mechanics model considering normal and tangential forces in boundary lubrication is developed for two real rough steel surfaces. The model is developed for real tribological systems and is flexible to different laboratory experiments. Tribochemistry (e.g. tribofilm formation and removal) and also mechanical properties are considered in this model. The amount of wear is calculated using a modified Archard’s wear equation accounting for local tribofilm thickness and its mechanical properties. This model can be used for monitoring the tribofilm growth on rough surfaces and also the real time surface roughness as well as changes in the λ ratio. This model enables the observation of in-situ tribofilm thickness and surface coverage and helps in better understanding the real mechanisms of wear

An Intronic Variant in the GRP78, a Stress-Associated Gene, Improves Prediction for Liver Cirrhosis in Persistent HBV Carriers

Background: Our previous study indicated that a common variant (rs430397 G>A) in the intron 5 of glucose-regulated protein 78 (GRP78) gene was associated with risk and prognosis of primary hepatocellular carcinoma (HCC), including HBV- and cirrhosis-related HCC. rs430397 polymorphism may be a contributing factor or biomarker of HBV infection or HBV-related cirrhosis. Methodology/Principal Findings: 539 non-HBV-infected individuals, 205 self-limited infection and 496 persistent HBV infection were recruited between January 2001 and April 2005 from the hospitals in Southern China. Genomic DNA was genotyped for rs430397. The associations between the variation and susceptibility to liver cirrhosis (LC) in persistent HBV infection were examined. We observed that individuals carrying allele rs430397A were more likely to become HBV-related LC. When persistently infected patients were divided into four subgroups, patients with phase IV had an increased allele A and genotype AG compared with phase I and/or phase III. Decreased serum albumin and prolonged plasma prothrombin time (PT) were showed in LC patients carrying genotype AA. Furthermore, rs430397 genotype had an increased susceptibility to LC with dose-dependent manners (P-trend = 0.005), and the genotype did constitute a risk factor for the development of advanced LC (Child-Pugh classification C and B, P-trend = 0.021). Conclusions/Significance: rs430397 polymorphism may be a contributing factor to LC in persistent HBV carriers. © 2011 Zhu et al.published_or_final_versio

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration