Transmission Mechanisms of Executive Compensation to Cost of Equity Capital

Kanyarat (Lek) Sanoran 사람과세계경영학회 2022 Global Business and Finance Review Vol.27 No.4

Purpose: The nature of each component of executive compensation varies, resulting in variances in executive incentives and investor pricing. To examine whether there is a differential relation between executive compensation components and cost of equity capital, this study decomposes the effects of executive compensation components on the cost of equity capital into wealth alignment, contribution, time horizon, and equity incentive effects. Design/methodology/approach: The hypotheses on the impact of each transmission mechanism of executive compensation component are separately developed in this study. The regression analyses are based on a sample of 11,649 firm-year observations of the U.S. listed companies during 1998-2014. Findings: The findings support all hypotheses by showing a significant reduction in cost of equity capital for bonus plans, long-term performance plans, and shareholdings, but a significant increase in cost of equity capital for salary and stock option. Research limitations/implications: The conclusions of this study are based on an examination of publicly listed companies in the United States; the hypotheses can be tested in other countries with various business environments and cultures. Originality/value: This study is a first attempt to explain the transmission mechanisms of executive compensation components and cost of equity capital by presenting evidence in support of wealth alignment effect, contribution effect, time horizon effect, and equity incentive effect.

Evaluation of Environmental Factors to Determine the Distribution of Functional Feeding Groups of Benthic Macroinvertebrates Using an Artificial Neural Network

박영석,Sovan Lek,전태수,Piet F.M. Verdonschot 한국생태학회 2008 Journal of Ecology and Environment Vol.31 No.3

Functional feeding groups (FFGs) of benthic macroinvertebrates are guilds of invertebrate taxa that obtain food in similar ways, regardless of their taxonomic affinities. They can represent a heterogeneous assemblage of benthic fauna and may indicate disturbances of their habitats. The proportion of different groups can change in response to disturbances that affect the food base of the system, thereby offering a means of assessing disruption of ecosystem functioning. In this study, we used benthic macroinvertebrate communities collected at 650 sites of 23 different water types in the province of Overijssel, The Netherlands. Physical and chemical environmental factors were measured at each sampling site. Each taxon was assigned to its corresponding FFG based on its food resources. A multilayer perceptron (MLP) using a backpropagation algorithm, a supervised artificial neural network, was applied to evaluate the influence of environmental variables to the FFGs of benthic macroinvertebrates through a sensitivity analysis. In the evaluation of input variables, the sensitivity analysis with partial derivatives demonstrates the relative importance of influential environmental variables on the FFG, showing that different variables influence the FFG in various ways. Collector-filterers and shredders were mainly influenced by Ca²+ and width of the streams, and scrapers were influenced mostly with Ca²+ and depth, and predators were by depth and pH. Ca²+ and depth displayed relatively high influence on all four FFGs, while some variables such as pH, %gravel, %silt, and %bank affected specific groups. This approach can help to characterize community structure and to ecologically assess target ecosystems. Functional feeding groups (FFGs) of benthic macroinvertebrates are guilds of invertebrate taxa that obtain food in similar ways, regardless of their taxonomic affinities. They can represent a heterogeneous assemblage of benthic fauna and may indicate disturbances of their habitats. The proportion of different groups can change in response to disturbances that affect the food base of the system, thereby offering a means of assessing disruption of ecosystem functioning. In this study, we used benthic macroinvertebrate communities collected at 650 sites of 23 different water types in the province of Overijssel, The Netherlands. Physical and chemical environmental factors were measured at each sampling site. Each taxon was assigned to its corresponding FFG based on its food resources. A multilayer perceptron (MLP) using a backpropagation algorithm, a supervised artificial neural network, was applied to evaluate the influence of environmental variables to the FFGs of benthic macroinvertebrates through a sensitivity analysis. In the evaluation of input variables, the sensitivity analysis with partial derivatives demonstrates the relative importance of influential environmental variables on the FFG, showing that different variables influence the FFG in various ways. Collector-filterers and shredders were mainly influenced by Ca²+ and width of the streams, and scrapers were influenced mostly with Ca²+ and depth, and predators were by depth and pH. Ca²+ and depth displayed relatively high influence on all four FFGs, while some variables such as pH, %gravel, %silt, and %bank affected specific groups. This approach can help to characterize community structure and to ecologically assess target ecosystems.

Oxalic acid assisted synthesis of the photochromic tungsten trioxide nanostructure

Parnumart Choopool,Lek Sikong,Kalayanee Kooptarnond 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12

The photochromic material, tungsten trioxide nanostructure has been successfully prepared by the simple precipitationmethod using nitric acid with the assistance of an oxalic acid. The effect of oxalic acid as the chelating agent on themorphologies, crystal structure, the optical properties and photochromic properties were investigated. The synthesizednanostructure characterized by X-ray diffractometer consisted of orthorhombic and hexagonal phase. The results fromscanning electron microscopy and transmission electron microscopy presented the flower-like shaped nanostructure formed bythe growth of many nanosheets. UV-vis spectrophotometer displayed the absorbance peak at lower than 550 nm. The band gapenergies of the products were decreased and the powder changed color from yellow to dark green after UV irradiation. Theproducts prepared with oxalic acid exhibited the highest photochromic effect due to the mixed phase of orthorhombic (81%)and hexagonal (19%) crystalline which having more defect concentration in its structure and the narrow band gap energy.

Electronic and Magnetic Properties of Copper Tetraazaporphyrin Influenced by Oxygen - a First-Principles Study

이재일,Beata Bia lek 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6

We present the results of the electronic structure calculations for a copper tetraazaporphyrin (CuTAP) model monolayer, both bare and interacting with oxygen. The results are compared with those obtained for copper phthalocyanine. We have found that the CuTAP ferromagnetic configuration is preferred over the paramagnetic one. The calculated value of the magnetic moment of the Cu atom in the CuTAP monolayer is 0.54 µB. It does not affect strongly the magnetic properties of the monolayer, in which all but pyrrole nitrogen atoms remain unpolarized. The presence of oxygen molecules in the vicinity of the metallic center of the CuTAP causes a decrease in the magnetic moment of Cu, but does not much influence the overall magnetic properties of the monolayer. However, it influences slightly the ground-state electronic structure of the monolayer, mainly due to the charge transfer between the tetraazaporphyrin ring and the O2 molecules.

Temperature-programmed desorption study of NO reactions on rutile TiO₂(110)-1×1

Kim, Boseong,Dohná,lek, Zdenek,Szanyi, Já,nos,Kay, Bruce D.,Kim, Yu Kwon Elsevier 2016 Surface science Vol.652 No.-

<P><B>Abstract</B></P> <P>Systematic temperature-programmed desorption (TPD) studies of NO adsorption and reactions on rutile TiO<SUB>2</SUB>(110)-1×1 surface reveal several distinct reaction channels in a temperature range of 50–500K. NO readily reacts on TiO<SUB>2</SUB>(110) to form N<SUB>2</SUB>O, which desorbs between 50 and 200K (LT N<SUB>2</SUB>O channels), which leaves the TiO<SUB>2</SUB> surface populated with adsorbed oxygen atoms (O<SUB>a</SUB>) as a by-product of N<SUB>2</SUB>O formation. In addition, we observe simultaneous desorption peaks of NO and N<SUB>2</SUB>O at 270K (HT1 N<SUB>2</SUB>O) and 400K (HT2 N<SUB>2</SUB>O), respectively, both of which are attributed to reaction-limited processes. No N-derived reaction product desorbs from TiO<SUB>2</SUB>(110) surface above 500K or higher, while the surface may be populated with O<SUB>a</SUB>'s and oxidized products such as NO<SUB>2</SUB> and NO<SUB>3</SUB>. The adsorbate-free TiO<SUB>2</SUB> surface with oxygen vacancies can be regenerated by prolonged annealing at 850K or higher. Detailed analysis of the three N<SUB>2</SUB>O desorption yields reveals that the surface species for the HT channels are likely to be various forms of NO dimers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N<SUB>2</SUB>O desorption from NO/TiO<SUB>2</SUB> is enhanced in the presence of oxygen vacancies (V<SUB>O</SUB>'s). </LI> <LI> Overall N<SUB>2</SUB>O yield saturates above a threshold NO dose. </LI> <LI> N<SUB>2</SUB>O yields on <I>h</I>-(or <I>r</I>-) TiO<SUB>2</SUB> are about the same with changes in desorption channels. </LI> <LI> Stabilization of NO in the presence of hydroxyls enhances LT and HT2 N<SUB>2</SUB>O channels. </LI> <LI> Oxidation of NO into NO<SUB>2</SUB> and NO<SUB>3</SUB> decreases the N<SUB>2</SUB>O desorption yield. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Isolation and Analysis of Bioactive Constituents of Sour Cherry (Prunus cerasus) Seed Kernel: An Emerging Functional Food

Istvan Bak,Istvan Lekli,Bela Juhasz,Edit Varga,Balazs Varga,Rudolf Gesztelyi,Levente Szendrei,Arpad Tosaki 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.4

A plant-based diet reduces the risk for the development of several chronic diseases, such as ischemic heart disease or cancer due to natural compounds found in plants. Numerous cereals, berries, fruits, and vegetables, including sour cherry (Prunus cerasus), which is a favored fruit worldwide, contain biological active components. The antioxidant components of the sour cherry seed kernel have not been investigated until now. The aim of our study was to isolate and analyze the bioactive constituents of sour cherry seed kernel. We separated the oil fraction of the kernel; then the remaining solid fraction was dried, and the oil-free kernel extract was further analyzed. Our results show that sour cherry seed kernel oil contains vegetable oils including unsaturated fatty acids, oleic acids, α-tocopherol, tocotrienols, and tocopherol-like components. The components of the solid fraction include various bioactive structures such as polyphenols, flavonoids, vegetable acids, and pro- and anthocyanidins, which could have useful therapeutic effects in the prevention of various vascular diseases.

Photocatalytic activity enhancement of Dy-doped TiO2 nanoparticles hybrid with TiO2 (B) nanobelts under UV and fluorescence irradiation

Thida San Nwe,Lek Sikong,Rungrote Kokoo,Matthana Khangkhamano 한국물리학회 2020 Current Applied Physics Vol.20 No.2

The main drawbacks of anatase titanium dioxide (TiO2) nanoparticles for being used as a photocatalyst are due to the rapid charge recombination of the electron-hole pairs and the wide band gap energy, limiting its photocatalysis application. To enhance photocatalytic activity, structure modification was performed here. Heterogeneous nanostructure of Dy-doped TiO2 nanoparticles hybrid with Monoclinic TiO2 nanobelts (Dy/TNBs) was fabricated via hydrothermal method. Annealing temperature was varied to investigate its effect on phase composition and morphology of the as-prepared TiO2 catalyst. Phase composition and morphology were studied by XRD and SEM, respectively. The effect of amount of catalyst loaded on the degradation efficiency of methylene blue (MB) dye in aqueous solution under UV and fluorescence illumination was investigated. The results showed that pure monoclinic TiO2 nanobelts (TNBs) was achieved at 450 °C. Enhanced photocatalytic activity under both UV and fluorescence irradiation was found on Dy/TNB samples. The optimum Dy dosage providing the highest MB degradation rates under both irradiation sources was 0.1 mol%.

Ammonia Formation from NO Reaction with Surface Hydroxyls on Rutile TiO₂(110)-1 × 1

Kim, Boseong,Kay, Bruce D.,Dohná,lek, Zdenek,Kim, Yu Kwon American Chemical Society 2015 The Journal of Physical Chemistry Part C Vol.119 No.2

<P>The reaction of NO with the hydroxylated rutile TiO2(110)-1 x 1 surface (h-TiO2) was investigated as a function of NO coverage using temperature-programmed desorption. Our results show that NO reaction with h-TiO2 leads to formation of NH3, which is observed to desorb at similar to 400 K. Interestingly, the amount of NH3 produced depends nonlinearly on the dose of NO. The yield increases up to a saturation value of similar to 1.3 x 10 (13) NH3/cm(2) at a NO dose of 5 x 10(-13) NO/cm(2), but subsequently decreases at higher NO doses. Preadsorbed H2O is found to have a negligible effect on the NH3 desorption yield. Additionally, no NH3 is formed in the absence of surface hydroxyls (HObs) upon coadsorption of NO and (HO)-O-2 on a stoichiometric TiO2(110) (s-TiO2(110)). On the basis of these observations, we conclude that nitrogen from NO has a strong preference to react with HObs on the bridge-bonded oxygen rows (but not with H2O) to form NH3. The absolute NH3 yield is limited by competing reactions of HOb species with titanium-bound oxygen adatoms to form H2O. Our results provide new mechanistic insight about the interactions of NO with hydroxyl groups on TiO2(110).</P>

Therapeutic Target Identification of Non-Alcoholic Fatty Liver Disease (NAFLD) through Patient Transcrip-tomic-Based in Vivo Functional Genetic Dissection

( Yong-an Lee ),( Chee Chong Lek ),( Gao Rong ),( Yee Siang Lim ),( Yun-shen Chan ),( Yock Young Dan ),( Ng Huck. Hui ),( Torsten Wuestefeld ) 대한간학회 2023 춘·추계 학술대회 (The Liver Week) Vol.2023 No.1

Lymphovascular invasion in colorectal cancers: can we predict it preoperatively?

Zarbaliyev Elbrus,Turhan Nihan,Çelik Sebahattin,Çağlıkülekçi Mehmet 대한대장항문학회 2024 Annals of Coloproctolgy Vol.40 No.3

Purpose: This study aimed to investigate preoperative predictors of lymphovascular invasion (LVI), which is a poor prognostic factor usually detected postoperatively in patients with colorectal cancer.Methods: Results for all patients operated on for colorectal cancer between January 1, 2006, and December 31, 2021, were retrospectively analyzed. Potential preoperative factors and postoperative pathology results were recorded. The patients were categorized as those with LVI and those without LVI. Potential factors that may be associated with LVI were compared between the 2 groups.Results: The study included 335 patients. The incidence of LVI was 3.11 times higher in patients with ascending colon tumors (odds ratio [OR], 3.11; 95% confidence interval [CI], 1.34–7.23; P=0.008) and 4.28 times higher in those with metastatic tumors (OR, 4.28; 95% CI, 2.18–8.39; P<0.001). Diabetes mellitus was inversely related to LVI in colorectal cancer patients; specifically, LVI was 56% less common in colorectal cancer patients with diabetes mellitus, irrespective of its duration (OR, 0.44; 95% CI, 0.25–0.76; P<0.001).ConclusionThe presence of preoperative LVI in colorectal cancer patients is difficult to predict. In particular, the effect of the effect of factors such as chronic disease accompanied by microvascular pathologies on LVI is still unclear. Advances in the neoadjuvant treatment of colorectal cancer patients, who are becoming more widespread every day, will encourage the investigation of different methods of preoperatively predicting LVI as a poor prognostic factor in these patients.