A Theory of Economic Sanctions

Baran Han 대외경제정책연구원(KIEP) 2012 Working Papers Vol.2012 No.1

This paper presents a work-horse model to analyze the mechanism of triadic sanctions, where the receiver of the sanction is not the actual target. With a motivating example of the US sanctions against Iran and a simple game theoretic framework, we show that the threat of such sanction is not credible in situations where the game ends after single stage, or when the entities are not concerned with future transactions amongst each other. In a repeated game setting, on the other hand, the threats become credible, but the level of enforcement would differ across firms/countries depending on the economic interdependency and how the parties perceive the probability that the games would continue to the next period.

Free vibration and harmonic response of cracked frames using a single variable shear deformation theory

Baran Bozyigit,Yusuf Yesilce,Magd Abdel Wahab 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.1

The aim of this study is to calculate natural frequencies and harmonic responses of cracked frames with general boundary conditions by using transfer matrix method (TMM). The TMM is a straightforward technique to obtain harmonic responses and natural frequencies of frame structures as the method is based on constructing a relationship between state vectors of two ends of structure by a chain multiplication procedure. A single variable shear deformation theory (SVSDT) is applied, as well as, Timoshenko beam theory (TBT) and Euler-Bernoulli beam theory (EBT) for comparison purposes. Firstly, free vibration analysis of intact and cracked frames are performed for different crack ratios using TMM. The crack is modelled by means of a linear rotational spring that divides frame members into segments. The results are verified by experimental data and finite element method (FEM) solutions. The harmonic response curves that represent resonant and anti-resonant frequencies directly are plotted for various crack lengths. It is seen that the TMM can be used effectively for harmonic response analysis of cracked frames as well as natural frequencies calculation. The results imply that the SVSDT is an efficient alternative for investigation of cracked frame vibrations especially with thick frame members. Moreover, EBT results can easily be obtained by ignoring shear deformation related terms from governing equation of motion of SVSDT.

Differential transform method and Adomian decomposition method for free vibration analysis of fluid conveying Timoshenko pipeline

Baran Bozyigit,Yusuf Yesilce,Seval Catal 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.1

The free vibration analysis of fluid conveying Timoshenko pipeline with different boundary conditions using Differential Transform Method (DTM) and Adomian Decomposition Method (ADM) has not been investigated by any of the studies in open literature so far. Natural frequencies, modes and critical fluid velocity of the pipelines on different supports are analyzed based on Timoshenko model by using DTM and ADM in this study. At first, the governing differential equations of motion of fluid conveying Timoshenko pipeline in free vibration are derived. Parameter for the nondimensionalized multiplication factor for the fluid velocity is incorporated into the equations of motion in order to investigate its effects on the natural frequencies. For solution, the terms are found directly from the analytical solution of the differential equation that describes the deformations of the cross-section according to Timoshenko beam theory. After the analytical solution, the efficient and easy mathematical techniques called DTM and ADM are used to solve the governing differential equations of the motion, respectively. The calculated natural frequencies of fluid conveying Timoshenko pipelines with various combinations of boundary conditions using DTM and ADM are tabulated in several tables and figures and are compared with the results of Analytical Method (ANM) where a very good agreement is observed. Finally, the critical fluid velocities are calculated for different boundary conditions and the first five mode shapes are presented in graphs.

Strengthening of deficient RC frames with high strength concrete panels: an experimental study

Baran, Mehmet,Susoy, Melih,Tankut, Tugrul Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.2

An economic, structurally effective and practically applicable strengthening technique was developed for reinforced concrete (RC) framed buildings. The idea of the technique is to convert the existing hollow brick infill wall into a load carrying system acting as a cast-in-place RC infill wall by bonding relatively thin high strength precast concrete PC panels to the plastered hollow brick infill. For this purpose, a total of eight one-third scale, one bay, one story frames were tested under reversed-cyclic lateral loads. Test frames were designed and constructed with common deficiencies observed in practice. Four different panel types were used for strengthening. Test results showed that both strength and stiffness of the frames were significantly improved by the introduction of PC panels. Experimental results were compared with the analytical approaches suggested by the authors.

Dynamic stiffness approach and differential transformation for free vibration analysis of a moving Reddy-Bickford beam

Baran Bozyigit,Yusuf Yesilce 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.5

In this study, the free vibration analysis of axially moving beams is investigated according to Reddy-Bickford beam theory (RBT) by using dynamic stiffness method (DSM) and differential transform method (DTM). First of all, the governing differential equations of motion in free vibration are derived by using Hamilton’s principle. The nondimensionalised multiplication factors for axial speed and axial tensile force are used to investigate their effects on natural frequencies. The natural frequencies are calculated by solving differential equations using analytical method (ANM). After the ANM solution, the governing equations of motion of axially moving Reddy-Bickford beams are solved by using DTM which is based on Finite Taylor Series. Besides DTM, DSM is used to obtain natural frequencies of moving Reddy-Bickford beams. DSM solution is performed via Wittrick-Williams algorithm. For different boundary conditions, the first three natural frequencies that calculated by using DTM and DSM are tabulated in tables and are compared with the results of ANM where a very good proximity is observed. The first three mode shapes and normalised bending moment diagrams are presented in figures.

Comprehensive Review of Factors Influencing the Use of Telepractice in Stuttering Treatment

Baran Bayati,Haleh Ayatollahi 대한의료정보학회 2021 Healthcare Informatics Research Vol.27 No.1

Objectives: Stuttering is a speech disorder characterized by the repetition of sounds, syllables, or words; prolongation ofsounds; and interruptions in speech. Telepractice allows speech services to be delivered to patients regardless of their location. This review investigated factors influencing the use of telepractice in stuttering treatment. Methods: Articles related tothe application of telepractice in stuttering were searched using the Scopus, Web of Science, PubMed, Cochrane, and Pro-Quest databases without consideration of any time limit. Initially, 79 articles were found and after application of the inclusionand exclusion criteria, 15 articles were selected for the review study. Data were analyzed by using the content analysis methodand synthesized narratively. Results: Factors influencing the use of telepractice in stuttering treatment were categorized intoindividual, technical, clinical, and economic factors. Providing access to healthcare services, maintaining personal privacy,and allowing flexibility in arranging appointments were among individual factors. In terms of the technical factors, technicalproblems and Internet speed were addressed. Clinical factors were divided into positive and negative outcomes, andeconomic factors were mainly related to time and cost savings. Conclusions: Although patients may benefit from using telepractice,the widespread adoption of this technology can be hindered by some technical and non-technical factors. Becausetelepractice can be employed as a complementary method to treat stuttering, more attention should be paid to the requiredinfrastructure and factors that may negatively impact the use of this technology.

Finite-Horizon Online Transmission Scheduling on an Energy Harvesting Communication Link with a Discrete Set of Rates

Baran Tan Bacinoglu,Elif Uysal-Biyikoglu 한국통신학회 2014 Journal of communications and networks Vol.16 No.3

As energy harvesting communication systems emerge, there is a need for transmission schemes that dynamically adapt to the energy harvesting process. In this paper, after exhibiting a finite-horizon online throughput-maximizing scheduling problem formulation and the structure of its optimal solution within a dynamic programming formulation, a low complexity online scheduling policy is proposed. The policy exploits the existence of thresholds for choosing rate and power levels as a function of stored energy, harvest state and time until the end of the horizon. The policy, which is based on computing an expected threshold, performs close to optimal on a wide range of example energy harvest patterns. Moreover, it achieves higher throughput values for a given delay, than throughput-optimal online policies developed based on infinite-horizon formulations in recent literature. The solution is extended to include ergodic time-varying (fading) channels, and a corresponding low complexity policy is proposed and evaluated for this case as well.

Optimal Status Updating with a Finite-Battery Energy Harvesting Source

Baran Tan Bacinoglu,Yin Sun,Elif Uysal,Volkan Mutlu 한국통신학회 2019 Journal of communications and networks Vol.21 No.3

We consider an energy harvesting source equipped with afinite battery, which needs to send timely status updates to a remotedestination. The timeliness of status updates is measured by a nondecreasingpenalty function of the age of information (AoI). Theproblem is to find a policy for generating updates that achieves thelowest possible time-average expected age penalty among all onlinepolicies. We prove that one optimal solution of this problem is amonotone threshold policy, which satisfies (i) each new update issent out only when the age is higher than a threshold and (ii) thethreshold is a non-increasing function of the instantaneous batterylevel. Let B denote the optimal threshold corresponding to the fullbattery level B, and p( ) denote the age-penalty function, then wecan show that p( B) is equal to the optimum objective value, i.e.,the minimum achievable time-average expected age penalty. Thesestructural properties are used to develop an algorithm to computethe optimal thresholds. Our numerical analysis indicates that theimprovement in average age with added battery capacity is largestat small battery sizes; specifically, more than half the total possiblereduction in age is attained when battery storage increases fromone transmission’s worth of energy to two. This encourages furtherstudy of status update policies for sensors with small batterystorage.

The pulsating hot subdwarf Balloon 090100001: results of the 2005 multisite campaign

Baran, A.,Oreiro, R.,Pigulski, A.,Herná,ndez, F. Pé,rez,Ulla, A.,Reed, M. D.,Rodrí,guez-Ló,pez, C.,Moskalik, P.,Kim, S.-L.,Chen, W.-P.,Crowe, R.,Siwak, M.,Armendarez, L.,Binder Blackwell Publishing Ltd 2009 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.392 No.3

<P>ABSTRACT</P><P>We present the results of a multisite photometric campaign on the pulsating B-type hot subdwarf star Balloon 090100001 (Bal09). The star is one of the two known hybrid hot subdwarfs with both long- and short-period oscillations, theoretically attributed to <I>g</I> and <I>p</I> modes. The campaign involved eight telescopes with three obtaining <I>UBVR</I> data, four <I>B</I>-band data and one Strömgren <I>uvby</I> photometry. The campaign covered 48 nights, providing a temporal resolution of 0.36 μHz with a detection threshold of about 0.2 mmag in <I>B</I>-filter data.</P><P>Bal09 has the richest pulsation spectrum of any known pulsating subdwarf B star, and our analysis detected 114 frequencies including 97 independent and 17 combination ones. Most of the 24 <I>g</I>-mode frequencies are between 0.1 and 0.4 mHz. Of the remaining 73, presumably <I>p</I> modes, 72 group into four distinct regions near 2.8, 3.8, 4.7 and 5.5 mHz. The density of frequencies requires that some modes must have degrees ℓ larger than 2. The modes in the 2.8 mHz region have the largest amplitudes. The strongest mode (<I>f</I><SUB>1</SUB>) is most likely radial, while the remaining ones in this region form two nearly symmetric multiplets: a triplet and quintuplet, attributed to rotationally split ℓ= 1 and 2 modes, respectively. We find clear increases of splitting in both multiplets between the 2004 and 2005 observing campaigns, amounting to ∼15 per cent on average. The observed splittings imply that the rotational rate in Bal09 depends on stellar latitude and is the fastest on the equator. We also speculate on the possible reasons for the changes of splitting. The only plausible explanation we find is torsional oscillation. This hypothesis, however, needs to be verified in the future by detailed modelling. In this context, it is very important to monitor the splittings on a longer time-scale as their behaviour may help to explain this interesting phenomenon.</P><P>The amplitudes of almost all terms detected in both 2004 and 2005 were found to vary. This is evident even during one season; for example, amplitudes of modes <I>f</I><SUB>8</SUB> and <I>f</I><SUB>C</SUB> were found to change by a factor of 2–3 within about 50 d during 2005.</P><P>We use a small grid of models to constrain the main mode (<I>f</I><SUB>1</SUB>), which most likely represents the radial fundamental pulsation. The groups of <I>p</I>-mode frequencies appear to lie in the vicinity of the consecutive radial overtones, up to the third one. Despite the large number of <I>g</I>-mode frequencies observed, we failed to identify them, most likely because of the disruption of asymptotic behaviour by mode trapping. The observed frequencies were not, however, fully exploited in terms of seismic analysis which should be done in the future with a larger grid of reliable evolutionary models of hot subdwarfs.</P>

Ultrasonographic evaluation of patients with abnormal liver function tests in the emergency department

Baran Umut Vardar,Carolyn S.Dupuis,Alan J. Goldstein,Zeynep Vardar,김영환 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.2

Ultrasonography is often the initial modality used to evaluate patients found to have abnormal liver function tests (LFTs) in the emergency department. While an assessment for biliary ductal dilatation and obstruction remains one of the main questions to answer, radiologists should also be aware of the ultrasonographic appearance of other conditions that can cause abnormal LFTs. This may be crucial for the management and disposition of patients in the emergency department. This article reviews the ultrasonographic features of diseases that may cause abnormal LFTs.