• Asia-Pacific Journal of Business
• /
• v.13 no.2
• /
• pp.23-37
• /
• 2022

Purpose - The purpose of this paper is to analyze the dynamic factors of the daily FX implied volatility based on the fractional integration methods focusing on long memory feature and structural changes. Design/methodology/approach - This paper uses the daily FX implied volatility data of the EUR-USD and the JPY-USD exchange rates. For the fractional integration analysis, this paper first applies the basic ARFIMA-FIGARCH model and the Local Whittle method to explore the long memory feature in the implied volatility series. Then, this paper employs the Adaptive-ARFIMA-Adaptive-FIGARCH model with a flexible Fourier form to allow for the structural changes with the long memory feature in the implied volatility series. Findings - This paper finds statistical evidence of the long memory feature in the first two moments of the implied volatility series. And, this paper shows that the structural changes appear to be an important factor and that neglecting the structural changes may lead to an upward bias in the long memory feature of the implied volatility series. Research implications or Originality - The implied volatility has widely been believed to be the market's best forecast regarding the future volatility in FX markets, and modeling the evolution of the implied volatility is quite important as it has clear implications for the behavior of the exchange rates in FX markets. The Adaptive-ARFIMA-Adaptive-FIGARCH model could be an excellent description for the FX implied volatility series

• Wind and Structures
• /
• v.32 no.3
• /
• pp.239-248
• /
• 2021

In this study, three airfoil families, NACA, FX and S, in each case three from each series with different shapes were investigated at different angles of attack using Computational Fluid Dynamics (CFD) method. To verify the CFD model, simulation results of the NACA 0012 airfoil was compared against the available experimental data and k-ω SST was used as the turbulence model. Lift coefficients, lift to drag ratios and pressure distributions around airfoils were obtained from the CFD simulations and compared each other. The simulations were performed at three Reynolds numbers, Re=2×105, 1×106and 2×106, and angle of attack was varied between -6 and 12 degrees. According to the results, similar lift coefficient values were obtained for symmetric airfoils reaching their maximum values at similar angles of attack. Maximum lift coefficients were obtained for FX 60-157 and S 4110 airfoils having lift coefficient values around 1.5 at Re=1×106 and 12 degrees of angle of attack. Flow separation occurred close to the leading edge of some airfoils at higher angles of attack, while some other airfoils were more successful in keeping the flow attached on the surface.

• Biomolecules & Therapeutics
• /
• v.27 no.5
• /
• pp.492-501
• /
• 2019

Nitrogen-containing heterocycles such as quinoline, quinazolinones and indole are scaffolds of natural products and have broad biological effects. During the last years those structures have been intensively synthesized and modified to yield new synthetic molecules that can specifically inhibit the activity of dysregulated protein kinases in cancer cells. Herein, a series of newly synthesized isoquinolinamine (FX-1 to 8) and isoindoloquinazolinone (FX-9, FX-42, FX-43) compounds were evaluated in regards to their anti-leukemic potential on human B- and T- acute lymphoblastic leukemia (ALL) cells. Several biological effects were observed. B-ALL cells (SEM, RS4;11) were more sensitive against isoquinolinamine compounds than T-ALL cells (Jurkat, CEM). In SEM cells, metabolic activity decreased with $10{\mu}M$ up to 26.7% (FX-3), 25.2% (FX-7) and 14.5% (FX-8). The 3-(p-Tolyl) isoquinolin-1-amine FX-9 was the most effective agent against B- and T-ALL cells with IC50 values ranging from 0.54 to $1.94{\mu}M$. None of the tested compounds displayed hemolysis on erythrocytes or cytotoxicity against healthy leukocytes. Anti-proliferative effect of FX-9 was associated with changes in cell morphology and apoptosis induction. Further, influence of FX-9 on PI3K/AKT, MAPK and JAK/STAT signaling was detected but was heterogeneous. Functional inhibition testing of 58 kinases revealed no specific inhibitory activity among cancer-related kinases. In conclusion, FX-9 displays significant antileukemic activity in B- and T-ALL cells and should be further evaluated in regards to the mechanisms of action. Further compounds of the current series might serve as templates for the design of new compounds and as basic structures for modification approaches.

• Journal of applied mathematics & informatics
• /
• v.19 no.1_2
• /
• pp.19-32
• /
• 2005

It is shown that the problem of minimizing (maximizing) a quadratic cost functional (quadratic gain functional) given the dynamics dx = (fx + gu)dt + hdb(t, a) where b(t, a) is a fractional Brownian motion of order a, 0 < 2a < 1, can be solved completely (and meaningfully!) by using the dynamical equations of the moments of x(t). The key is to use fractional Taylor's series to obtain a relation between differential and differential of fractional order.

• Journal of Information Technology Applications and Management
• /
• v.21 no.4
• /
• pp.1-13
• /
• 2014

This study aims to show the risk reduction effects of round-the-clock trading environment. We analyse the trading results of the currency futures contracts in CME Globex which are open 23 hours a day. These include Euro FX, Japanese Yen, Australian Dollar, and British Pound from January 2005 to August 2013. We generate new price series using only daytime prices during about 7-hour period. This hypothetical "G" data series may have greater gap risk than the original "R" data series. Empirical results show the trading risk reduction effects, that is R data series have higher profits and lower risks than G data series.

• Journal of the Korean Data and Information Science Society
• /
• v.24 no.1
• /
• pp.161-170
• /
• 2013

The FX (Foreign Exchange) is a form of exchange for the global decentralized trading of international currencies. The simple sense of Forex is simultaneous purchase and sale of the currency or the exchange of one country's currency for other countries'. We can find the consistent rules of trading by comparing the gradient boosting method and the decision trees methods. Methods such as time series analysis used for the prediction of financial markets have advantage of the long-term forecasting model. On the other hand, it is difficult to reflect the rapidly changing price fluctuations in the short term. Therefore, in this study, gradient boosting method and decision tree method are applied to analyze the short-term data in order to make the rules for the revenue structure of the FX market and evaluated the stability and the prediction of the model.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.24 no.2
• /
• pp.11-19
• /
• 1987

A Series 60, $C_b=0.60$ model was tested in the towing tank of Seoul National University. Total resistance, hull attitude, wake distributions and wave measured at FR condition(free trim and sinkage) and FX condition(fixed trim and sinkage). From the measured data, residual, viscous and wave pattern resistance components were evaluated and compared. It is found that the changes in wetted surface area should be considered in predictions of frictional resistances, and can be easily found from hydrostatic data and measured mean sinkages without additional tests. Applications of the concept to the geosim tests of Series 60, Wigley, Lucy Ashton models show that the conventional extrapolation method can be improved considerably.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.11 no.1
• /
• pp.1-11
• /
• 1989

This is a retrospective study on maxillofacial fractures. This study was based on a series of 442 patients with maxillofacial fractures treated at Dept, of oral and Maxillofacial Surgery, College of Dentistry, Chon Buk National University from Jan, 1984 to Sep. 1988. The results obtained were as follows: 1. The ratio of Male/Female was 4.8 : 1, and 3rd decade (43.9%) was the highest age group in incidence. 2. Monthly incidence was the highest in Oct,(10.6%). 3. The most frequent maxillofacial fracture site was mandible (70.0%), and zygoma & zygomatic arch (13.6%), maxilla(11.7%) and nasal bone (4.7%) were next in order of frequency. 4. Traffic accidents (47.5%), fight(24.8%) were the most common causes of maxillofacial fractures. 5. The most frequent chief complaint was painful swelling(40.7%). 6. In mandibular fractures, the most frequent fracture site was symphyseal area(28.9%) and simple fracture was the most frequent in type of fracture (71.2%). 7. In maxillary fractures, fracture with other facial bones (64.5%) was more frequent than fracture of maxilla only. The most common type of fracture was unilateral fractures(37.1%). 8. In fracture of zygoma complex, zygoma fracture was the most frequent fracture type(40.3%), zygoma and zygomatic arch fx, (30.6%), zygomatic arch fx, (29.1%) were next in order 9. Open reduction was major method of treatment in maxillofacial fractures : Mandible (77.5%), Maxilla (61.3%), Zygoma complex(43.1%). 10. Maxillofacial fractures were most frequently combined with head injury(39.3%), and lower extremities(17.0%), upper extremities(13.6%) were next in order.

• Wind and Structures
• /
• v.36 no.2
• /
• pp.105-120
• /
• 2023

The present study is performed to find the effect of corner recession on a square plan-shaped tall building. A series of numerical simulations have been carried out to find the two orthogonal wind force coefficients on various model configurations using Computational Fluid Dynamics (CFD). Numerical analyses are performed by using ANSYS-CFX (k-ℇ turbulence model) considering the length scale of 1:300. The study is performed for 0° to 360° wind angle of attack. The CFD data thus generated is utilised to fit parametric equations to predict alongwind and crosswind force coefficients, C_fx and C_fy. The precision of the parametric equations is validated by employing a wind tunnel study for the 40% corner recession model, and an excellent match is observed. Upon satisfactory validation, the parametric equations are further used to carry out multiobjective optimization considering two orthogonal force coefficients. Pareto optimal design results are presented to propose suitable percentages of corner recession for the study building. The optimization is based on reducing the alongwind and crosswind forces simultaneously to enhance the aerodynamic performance of the building.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.12
• /
• pp.3310-3329
• /
• 2023

This work designs an eighteen-channel bidirectional Intensity Modulation with Direct Detection (IM/DD) Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) system. The proposed system meets the requirement of the ITU-T 5G fronthaul link suggested design in G-series Recommendations-Supplement 66. The newly designed system, with a 25Gb/s/λ data rate (450Gbps as a system capacity), has been tested and simulated using OptiSystem V.19 software. The system has been evaluated by the BER with respect to variable the optical span and CW laser power. Based on the ITU-T recommendations, the simulation results demonstrate that this system might be used as an F1 and as an Fx 5G fronthaul link for functional split choices starting from options 1 to 7a. These options are required under 25Gbps/λ for each upstream and downstream link direction. Furthermore, the proposed system utilized a bidirectional single-mode optical fiber within short optical spans of up to 10 km. The proposed system is characterized by a low-cost, simple, DSP-free and amplifier-free system with a reasonable system capacity.