Positive Dependence Research Articles

Exploring Two Modified Ali-Mikhail-Haq Copulas and New Bivariate Logistic Distributions

The Ali-Mikhail-Haq copula is a bivariate ratio-type Archimedean copula known for its simplicity and flexibility in modeling moderate negative and positive dependence structures, making it widely used in various fields. However, it is limited to capturing asymmetric dependence features, significant negative correlations, or versatile tail dependence properties. This research paper proposes two modifications of the Ali-Mikhail-Haq copula that overcome these limitations, but at the price of the loss of the positive dependence nature. Contrary to the common approach that focuses on modifying the corresponding generator function, we apply direct functional changes to the Ali-Mikhail-Haq copula. We thus perturb its Archimedean identity. The first copula has the particularity of being non-exchangeable, capable of reaching an interesting level of negative dependence correlations, and possessing flexible tail dependence properties. The second copula offers another modeling option; it is exchangeable like the Ali-Mikhail-Haq copula, but it benefits from a broader range of negative dependence correlations and more adaptable tail dependence properties. For the two proposed copulas, we investigate their main characteristics, including quadrant dependence, copula density function, conditional copulas, couples of value generation, extended variants via standard copula schemes, comprehensive copula orders, and weighted harmonic mean copula transformations. An application on two new bivariate logistic distributions in a two-component system context is given. When possible, numerical and graphical studies are given to strengthen the theory.

PH regulates the formation of organosulfates and inorganic sulfate from organic peroxide reaction with dissolved SO2 in aquatic media

Abstract. Organic peroxides (OPs) are an important component of dissolved organic matter (DOM), detected in various aquatic media. Despite their unique functions as redox agents in water ecosystems, the complete mechanisms and factors controlling their transformation are not explicitly established. Here, we evaluate the pH effect on the aqueous-phase reaction of three selected OPs (methyl hydroperoxide (MHP), peracetic acid (PAA), and benzoyl peroxide (BZP)) with dissolved SO2. Results show that due to the presence of the hydroperoxyl group in their structures, MHP and PAA are susceptible to forming inorganic sulfate and organosulfate (methyl sulfate for MHP and acetyl sulfate for PAA) depending on the pH, while BZP exclusively forms organosulfate (benzoyl sulfate) in the pH range investigated. Moreover, it is seen that the ability of PAA to form inorganic sulfate relative to organosulfate is more pronounced, which is supported by a previous experimental observation. The effective rate constants of the transformation of these peroxides within the pH 1–10 and 240–340 K ranges exhibit positive pH and temperature dependencies, and BZP is seen to degrade more effectively than MHP and PAA. In addition to the pH impact, it is highlighted that the formation of organic and/or inorganic sulfate strongly depends on the nature of the substituents on the peroxy function. Namely, PAA and BZP are more reactive than MHP, which may be attributed to the electron-withdrawing effects of -C(O)R (R = -CH3 and -C6H5 for PAA and BZP, respectively) substituents that activate the peroxy function. The results further indicate that the aqueous-phase degradation of OPs can adequately drive the change in the chemical composition of DOM, both in terms of organic and inorganic sulfate mass fractions.

Positive dependence for colored percolation.

For uniform random 4-colorings of graph edges with colors {a,b,c,d}, every two colors form a 1/2- percolation, and every two overlapping pairs of colors form independent 1/2-percolations. We show positive mutual dependence for pairs of colors ab,ac, and ad, and negative mutual dependence for pairs of colors ab,ac, and bc. The proof is based on a generalization of the Harris-Kleitman inequalities. We apply the results to crossing probabilities for the colored bond and site percolation, and to colored critical percolation that we also define.

Black Hole Mass and Eddington-ratio Distributions of Less-luminous Quasars at z ∼ 4 in the Subaru Hyper Suprime-Cam Wide Field

We investigate the black hole mass function (BHMF) and Eddington-ratio distribution function (ERDF) of broad-line active galactic nuclei (AGNs) at z = 4, based on a sample of 52 quasars with i < 23.2 at 3.50 ≤ z ≤ 4.25 from the Hyper Suprime-Cam Subaru Strategic Program S16A-Wide2 data set, and 1462 quasars with i < 20.2 in the same redshift range from the Sloan Digital Sky Survey data release 7 quasar catalog. Virial black hole (BH) masses of quasars are estimated using the width of the CIV 1549 Å line and the continuum luminosity at 1350 Å. To obtain the intrinsic broad-line AGN BHMF and ERDF, we correct for the incompleteness in the low-mass and/or low-Eddington-ratio ranges caused by the flux-limited selection. The resulting BHMF is constrained down to logMBH/M⊙∼7.5 . In comparison with broad-line AGN BHMFs at z ∼ 2 in the literature, we find that the number density of massive SMBHs peaks at higher redshifts, consistent with the downsizing evolutionary scenario. Additionally, the resulting ERDF shows a negative dependence on BH mass, suggesting more massive SMBHs tend to accrete at lower-Eddington ratios at z = 4. With the derived intrinsic broad-line AGN BHMF, we also evaluate the active fraction of broad-line AGNs among the entire SMBH population at z = 4. The resulting active fraction may suggest a positive dependence on BH mass. Finally, we examine the time evolution of broad-line AGN BHMF between z = 4 and 6 through solving the continuity equation. The results suggest that the broad-line AGN BHMFs at z = 4–6 only show evolution in their normalization, but with no significant changes in their shape.

Investigation of the dielectric recovery process of vacuum arc in double breaks by planar laser-induced fluorescence

The multibreak vacuum circuit breaker uses multiple short gaps to interrupt the fault current, greatly improving the dielectric strength, and is a viable method to realize high-voltage interruption. The metal vapor distribution near the current zero is crucial for the dielectric recovery process in the multibreak vacuum circuit breaker. Due to the complicated dielectric construction and the interaction between the breakers, the vacuum arc inevitably deviates from the axisymmetric distribution during the interruption process. The traditional diagnosis method limited to 0D or 1D is not sufficient to study the real distribution of metal vapor near the current zero. To address these issues, we developed a planar laser-induced fluorescence method to measure the 2D distribution of copper vapor near the current zero by detecting 510.6 nm fluorescence intensity. The results indicate that for the butt contacts, the copper vapor is diffused in the gap of the high-voltage break and aggregated on the cathode surface of the low-voltage break. The axial magnetic field and transverse magnetic field affect the 2D copper vapor distribution and eliminate the inconsistency, which is achieved by affecting the motion of charged particles and the ionization-recombination process. Furthermore, the copper vapor density exhibits a positive dependence on the arc current, and the magnetic field impacts the density increase rate and distribution mode.

Computational investigation of HO•-induced atmospheric transformation and ecological risk assessment of 2-methyl-4-chlorophenoxyacetic acid

2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a pervasive phenoxyacetic acid herbicide, frequently identified in environmental matrices. This study undertakes a systematic investigation of the atmospheric environmental transformation behavior and potential ecological risks of hydroxyl radical (HO•) induced MCPA for the first time, employing computational chemistry and computational toxicology methodologies. Our findings indicate that the initial degradation of MCPA can be triggered by both HO•-addition and hydrogen-abstraction reactions, with the latter being more likely to occur. The primary reaction pathways were identified as R2, R3, R8, and R13. The total rate constant for the gas-phase reaction of MCPA with HO• was calculated as 8.59 × 10−12 cm3 molecule −1 s−1 at 298 K. This total rate constant displayed a distinct positive temperature dependence within the temperature range of 250–375 K. Structures of 25 transformation products, which include 7 experimentally observed compounds, were determined from further reactions of crucial intermediates. The toxicity assessment of MCPA and its transformation products indicated that most of the hydroxyl oxidation products exhibit toxicity to aquatic organisms and possess mutagenic, developmental toxic, non-genotoxic carcinogenic, and skin irritating or corrosive properties. This research contributes to a comprehensive understanding of the transformation mechanisms, kinetics, and environmental repercussions of gas-phase MCPA, enhancing our ability to predict and mitigate its ecological impact.

A theoretical and experimental study of 2-ethylfuran + OH reaction

2-Ethylfuran (EF2), having similar thermophysical properties as gasoline, can be produced from biomass and has received increasing attention in recent years. The reaction of EF2 with OH radical plays a fundamental role in combustion chemistry of furan fuels. This work provides a comprehensive investigation on the reaction kinetics of the title reaction. The performance of several density functional theory methods is evaluated against the DLPNOCCSD(T)/CBS(T-Q) benchmark method. The results show that M08-HX/jun-cc-pVTZ is the best one for both abstraction and addition reactions with the lowest average unsigned deviations of 0.61 and 0.63 kcal mol−1, respectively. Multi-structural variational transition state theory combined with small-curvature tunneling approximation (MS-CVT/SCT) is employed to calculate the high-pressure limit (HPL) rate constants over a wide temperature range of 500−2000 K. The system-specific quantum Rice-Ramsperger-Kassel (SS-QRRK) method is used to obtain the pressure-dependent rate constants for addition reactions at several selected pressures from 0.01 to 100 atm. We have measured the rate constants of EF2 + OH reaction behind reflected shock wave at temperatures of 985−1342 K and pressure around 1 bar. The measured rate constants exhibit a positive temperature dependence and may be described by a three-parameter Arrhenius expression: k=1.28×10−10×T6.89exp(5318T) (cm3 mol−1 s–1). The calculated results are in good agreement with measurements and the total rate constants exhibit a non-monotonic temperature dependence due to the competition between the abstraction and addition channels. At the HPL, the addition reaction is dominant, and the branching ratio is larger than abstraction reaction at 500–1800 K and is 0.92 at 500 K. Finally, to evaluate the performance of our calculations on the ignition delay time of EF2, three available kinetic models (Somers et al., Xu et al. and Li et al.) of EF2 are updated and the results show that the predictions of Li's model are improved.

Exploring polymorphism in a palatable prey: predation risk and frequency dependence in relation to distinct levels of conspicuousness.

Camouflage and warning signals are different antipredator strategies, which offer an excellent opportunity to study the evolutionary forces acting on prey appearance. Edible prey often escape detection via camouflage, which usually leads to apostatic selection favoring rare morphs. By contrast, defended prey often display conspicuous coloration acting as warning signals to predators, which usually leads to positive frequency dependence and signal uniformity. However, when two morphs of the same species vary greatly in conspicuousness, the maintenance of both cryptic and conspicuous forms in profitable prey populations remains enigmatic. Using the white and melanic morphs of the invasive box tree moth (Cydalima perspectalis) presented at three different frequencies, we investigate (a) the palatability of caterpillars and adult moths to birds, (b) predation rates on the less conspicuous melanic morph, and (c) the role of frequency dependence in balancing morph frequencies. Our results show that caterpillars are distasteful for birds but not adult moths that are fully palatable. We found that the less conspicuous, melanic morph, benefits from reduced predation due to its lower detectability. The more conspicuous, white morph, instead, is more predated and is best off when common, suggesting positive frequency dependence. These results offer new insights into the evolution of color polymorphism and prey defenses in a polymorphic moth species. Further investigation is required to understand the role of different predation regimes on the maintenance of the polymorphism in this species and test whether additional selection pressures operate in natural populations.

Fast data-dependence profiling through prior static analysis

Data-dependence profiling is a program-analysis technique for detecting parallelism opportunities in sequential programs. It captures data dependences that actually occur during program execution, filtering parallelism-preventing dependences that purely static methods assume only because they lack critical runtime information, such as the values of pointers and array indices. Profiling, however, suffers from high runtime overhead. In our earlier work, we accelerated data-dependence profiling by excluding polyhedral loops that can be handled statically using certain compilers and eliminating scalar variables that create statically-identifiable data dependences. In this paper, we combine the two methods and integrate them into DiscoPoP, a data-dependence profiler and parallelism discovery tool. Additionally, we detect reduction patterns statically and unify the three static analyses with the DiscoPoP framework to significantly diminish the profiling overhead and for a wider range of programs. We have evaluated our unified approaches with 49 benchmarks from three benchmark suites and two computer simulation applications. The evaluation results show that our approach reports fewer false positive and negative data dependences than the original data-dependence profiler and reduces the profiling time by at least 43%, with a median reduction of 76% across all programs. Also, we identify 40% of reduction cases statically and eliminate the associated profiling overhead for these cases.

On the dynamic performance of additively manufactured visco-elastic meta-materials

Additive manufacturing (AM) has revolutionized the production of structures with tailored material properties, including elastomer polyurethanes (EPU) which exhibit exceptional mechanical performance. EPU possesses unique characteristics, such as high elongation at break, efficient energy dissipation, and superior specific strength, making it well-suited for applications requiring resilience to dynamic loadings. By combining the advantages of AM and EPU, enhanced and customized meta-materials can be created, surpassing the mechanical performance of traditional bulk materials. However, because of the non-linear stress–strain response of both the constitutive material and the structure, designing such meta-materials for high strain-rates can be challenging. In this work, therefore, quasi-static and dynamic experiments were conducted to evaluate a meta-material architecture. The investigation revealed a strong positive rate dependency. The mechanical performances, including strength, and dissipated energy, increased with increasing loading rate. The EPU meta-materials demonstrate their suitability for dynamic applications where high energy dissipation is crucial for reducing transmitted loads.

Do local governments tax homeowner communities differently?

AbstractThis article investigates whether and how strongly the share of homeowners in a community affects residential property taxation by local governments. Different from renters, homeowners bear the full property tax burden, irrespective of local market conditions, and the tax is more salient to them. “Homeowner communities” may hence oppose high property taxes in order to protect their housing wealth. By merging granular spatial data from a complete housing inventory in the 2011 German Census with historical homeownership rates and housing damages during the Second World War as sources of exogenous variation in local homeownership, we provide empirical evidence that otherwise identical jurisdictions charge significantly lower property taxes when the share of homeowners in their population is higher. This result is invariant to local market conditions, which suggests tax salience is the key mechanism behind this effect. Moreover, we find positive spatial dependence on tax multipliers, indicative of property tax mimicking by local governments.

Allylic-alkylic C-C bond decomposition in 1-butene and 1-pentene

1-Butene and 1-pentene are critical intermediates in the oxidation and pyrolysis of larger alkanes and alcohols. Their thermal decomposition plays important role in fuel consumption under combustion conditions, yet seldom investigated. In this work, we studied the title reactions behind reflected shock waves over temperatures of 1178 – 1416 K and pressures near 1.2 bar. We monitored absorbance time-history of the product allyl radicals by employing a sensitive UV diagnostic scheme at a wavelength of 220 nm. We extracted the target rate coefficients by simulating the measured absorbance profiles with detailed kinetic models. Our determined rate coefficients of 1-butene (k1) and 1-pentene (k2) thermal decomposition may be expressed as (unit s−1):k1(1C4H8→CH3+aC3H5)=1.52×1016e(−37937T)k2(1C5H10→C2H5+aC3H5)=3.84×1014e(−31434T)We believe the current work provides the first direct measurements of these reactions. Our 1-butene thermal decomposition rate coefficients exhibit a positive Arrhenius temperature dependence. Around 1350 K and 1 bar, 1-butene decomposition proceeds ∼ 4.5 times faster than n-butane, and ∼ 66 times faster than 1,3-butadiene. Our work extends the literature measurements of 1-butene decomposition to temperatures higher than 1310 K. Literature measurements above 1000 K underestimate our rate coefficients by ∼ 20 %. Additionally, our 1-butene rate coefficients provide an analogy to bio-derived molecules containing similar allylic-alkylic C-C bonds, such as methyl-3-hexenoate. For 1-pentene thermal decomposition, we observed the product allyl radicals starting from 1178 K compared to 1213 K in 1-butene measurements. Thus 1-pentene decomposition proceeds 2 – 6 times faster than 1-butene, and shows a gentler Arrhenius temperature dependence. The current literature models exhibit a range of rate values that vary by an order of magnitude, resulting in noticeable discrepancies. Our study addresses this issue by providing much-needed clarity and precision. Furthermore, we implemented our rate coefficients in literature kinetic models and evaluated their influence on ignition delay time (IDT) and speciation measurements. The results indicate that our rate coefficients generally improved the model performance.

Effect of Zr content on the strain rate sensitivity of nanohardness of Ti-Zr-Cu-Ni-Al thin film metallic glass

The strain rate sensitivity of nanohardness of a magnetron sputtered Ti-Zr-Cu-Ni-Al thin film metallic glass has been investigated. Nanoindentation tests were performed at various loading rates on thin film metallic glasses with three different Zr content. Replacement of Ti with Zr has led to an increase in hardness due to higher atomic packing efficiency and stronger bonds. A non-serrated p-h curve independent of Zr content and a positive dependency of nanohardness on Zr content was observed. The negative strain rate sensitivity and enhancement of strain rate sensitivity with Zr content were discussed.

EMPOWERING JUNIOR HIGH SCHOOL STUDENTS' EMPATHY AND COLLABORATION WITH DESIGN THINKING AND PJBL

This research seeks to guide the empathy of junior high school students through combining design thinking with PjBL (Project Based Learning) as many as 83 students, and two science teachers participated in this research. Data collection was carried out through interviews, observation notes, reflection notes, and student assessment rubrics to collect qualitative data. Aspects of student empathy and collaboration are built into the learning of digestive system material. Empathy as an initiator in project-based learning includes aspects of self-integrity and empathy for others which are closely related to elements of collaboration including aspects of cooperation, ways of communicating, positive dependence and social coordination. Design thinking as a process thinking framework includes the empathization stage, problem formulation, constructing ideas, constructing prototypes, and tests as student learning stages. Contextual learning with design thinking and PjBL is expected to be an integrated model to achieve aspects of the Pancasila student profile and 21st century skills.

Evolution of realized niche breadth diversity driven by community dynamics.

Why many herbivorous insects are host plant specialists, with non-negligible exceptions, is a conundrum of evolutionary biology, especially because the host plants are not necessarily optimal larval diets. Here, I present a novel model of host plant preference evolution of two insect species. Because habitat preference evolution is contingent upon demographic dynamics, I integrate the evolutionary framework with the modern coexistence theory. The results show that the two insect species can evolve into a habitat specialist and generalist, when they experience both negative and positive frequency-dependent community dynamics. This happens because the joint action of positive and negative frequency dependence creates multiple (up to nine) eco-evolutionary equilibria. Furthermore, initial condition dependence due to positive frequency dependence allows specialization to poor habitats. Thus, evolved habitat preferences do not necessarily correlate with the performances. The model provides explanations for counterintuitive empirical patterns and mechanistic interpretations for phenomenological models of niche breadth evolution.

Optimality conditions and constraint qualifications for cardinality constrained optimization problems

The cardinality constrained optimization problem (CCOP) is an optimization problem where the maximum number of nonzero components of any feasible point is bounded. In this paper, by rewriting the cardinality constraint as a constraint requiring that any feasible point must lie in the union of certain subspaces, we consider CCOP as a mathematical program with disjunctive subspaces constraints (MPDSC). Since a subspace is a special case of a convex polyhedral set, MPDSC is a special case of the mathematical program with disjunctive constraints (MPDC). Using the special structure of subspaces, we are able to obtain more precise formulas for the tangent and (directional) normal cones for the disjunctive set of subspaces. We then obtain first and second order optimality conditions by using the corresponding results from MPDC. Thanks to the special structure of the subspace, we are able to obtain some results for MPDSC that do not hold in general for MPDC. In particular we show that the relaxed constant positive linear dependence (RCPLD) is a sufficient condition for the metric subregularity/error bound property for MPDSC which is not true for MPDC in general. Finally we show that under all constraint qualifications presented in this paper, certain exact penalization holds for CCOP.

Why cultural distance can promote - or impede - group-beneficial outcomes.

Quantifying the distance between cultural groups has received substantial recent interest. A key innovation, borrowed from population genetics, is the calculation of cultural FST (CFST) statistics on datasets of human culture. Measuring the variance between groups as a fraction of total variance, FST is theoretically important in additive models of cooperation. Consistent with this, recent empirical work has confirmed that high values of pairwise CFST (measuring cultural distance) strongly predict unwillingness to cooperate with strangers in coordination vignettes. As applications for CFST increase, however, there is greater need to understand its meaning in naturalistic situations beyond additive cooperation. Focusing on games with both positive and negative frequency dependence and high-diversity, mixed equilibria, we derive a simple relationship between FST and the evolution of group-beneficial traits across a broad spectrum of social interactions. Contrary to standard assumptions, this model shows why FST can have both positive and negative marginal effects on the spread of group-beneficial traits under certain realistic conditions. These results provide broader theoretical direction for empirical applications of CFST in the evolutionary study of culture.

Bexarotene-induced hypothyroidism and dyslipidemia; a nation-wide study.

Central hypothyroidism and dyslipidemia are well-known adverse events (AEs) of bexarotene therapy. Although hypothyroidism is known to cause dyslipidemia, no study has examined the association between hypothyroidism and dyslipidemia in patients undergoing bexarotene therapy. The aim of this study is to examine this association. A retrospective observational study was performed among 294 patients who initiated bexarotene therapy in Japan (nation-wide postmarketing complete surveillance). Jonckheere-Terpstra (one sided) test was performed to evaluate the effect of the bexarotene dose on lipid metabolisms, and regression analyses were performed to evaluate associations of bexarotene dose, free thyroxine (FT4), body mass index (BMI), and lipid metabolisms. Most patients developed hypothyroidism. Two-third of patients showed FT4 values below the lower limit at 1 week. Triglycerides (TG) increased in a bexarotene dose-dependent manner, and grade ≥3 AEs on hypertriglyceridemia was observed in 39% of the patients. Additionally, one-third of grade ≥3 AEs on hypertriglyceridemia occurred within 1 week. The delta_FT4 (difference in FT4 from baseline) negatively correlated with TG increase at 1 week (p = 0.012) but not with low density lipoprotein cholesterol (LDL-C) increase at any week. Bexarotene-induced hypothyroidism is almost inevitable and occurred quickly. Bexarotene-induced hypertriglyceridemia showed positive bexarotene dose dependency and negative delta_FT4 dependency. Prophylactic and appropriate thyroid hormone compensation therapy and starting bexarotene at low doses with subsequent titration while managing dyslipidemia may have a beneficial effect for the successful continuation of bexarotene therapy without severe endocrine and metabolic AEs.

Design and synthesis of an environment-sensitive 3-methyleneisoindolin-1-one fluorophore for labeling DNA-interacting proteins.

We designed 6-dimethylamino 3-methyleneisoindolin-1-one as an environment-sensitive fluorophore, examining its applications for protein labeling. Synthesized 3-methyleneisoindolin-1-one exhibits solvatochromic fluorescence (λemmax; 472 nm in 2-PrOH, 512 nm in H2O). A positive linear dependence between λemmax and solvent dielectric constant (DC), as well as between Stokes shift and DC, and a negative correlation between fluorescence quantum yield and DC are observed in protic solvents. These properties are similar to those of the oxygen isosteric fluorophore, 4-dimethylaminophthalimide, a slovatochromic fluorophore utilized for labeling oligodeoxynucleotides (ODNs) and peptides. Notably, fluorescence intensity of 3-methyleneisoindolin-1-one is higher than the phthalimide in protic solvents used in this study. The 3-methyleneisoindolin-1-one demonstrated the higher stability in pH 8 solution than in pH 6 solution in contrast to the stability profile of the phthalimide, which was stable at pH 6 but was hydrolyzed at pH 8. We also synthesized an o-keto benzaldehyde derivative that converts a primary amine to 6-dimethylamino 3-methyleneisoindolin-1-one under biocompatible conditions and introduced it into ODNs for turn-on fluorescent protein labeling. The synthesized ODN with a protein-binding sequence of Escherichia coli DnaA was employed to modify the DNA-binding domain of DnaA, and the fluorescent properties of the modified protein were investigated.

Heptanone isomers as biofuel: Reactivity with OH radicals

The reactions of heptanone isomers, namely diisopropyl ketone (DIPK, k1), isopropyl propyl ketone (IPPK, k2), and dipropyl ketone (DPK, k3), with OH radicals play a crucial role in predicting their combustion behavior. We conducted the first high-temperature measurements of these reactions over the temperature range of 876 to 1328 K at pressures near 1 bar. The determined overall rate coefficients may be described as (unit of cm3molecule−1s−1):k1=2.13×10−10e(−2684T)k2=2.42×10−10e(−2733T)k3=2.84×10−10e(−2808T)Over the investigated high temperature range, all three reactions exhibit a positive temperature dependence, with activation energies ranging 5.3 to 5.6 kcal mol−1. We did not observe discernible pressure dependence within the pressure range of 0.66 to 1.66 bar. At 1250 K, DPK reacts with OH radicals 11 % faster than IPPK and 21 % faster than DIPK. Interestingly, compared to heptane, which reacts twice as fast, the presence of the C=O group significantly hinders the reactivity of the normal chain heptanone (DPK) towards OH radicals. Furthermore, the rate coefficients of OH + DIPK reaction in literature models underestimate the measured activation energy and overpredict the overall rate coefficients. To enhance the accuracy of SAR prediction for OH + ketone reactions, a multiplicative factor of 0.6 - 0.75 is suggested. Additionally, this study provides a site-specific expression for the tertiary CH bonds adjacent to the C=O bond in ketone molecules, expanding the applicability of the NNN (next-nearest-neighbor) prediction scheme to encompass larger branched ketones.