• Earthquakes and Structures
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• v.3 no.3_4
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• pp.611-628
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• 2012

The inelastic earthquake response of existing, reinforced concrete buildings with an open ground story, designed according to the old Greek codes, is investigated before and after their seismic strengthening with steel braces restricted to the open ground stories. The seismic performance evaluation is based on Part 3 of Eurocode 8 for assessment and retrofitting of buildings. Three and five-story, symmetric and non-symmetric buildings are subjected to a set of seven pairs of synthetic accelerograms, compatible with the design spectrum, and conclusions are drawn regarding the effectiveness of the strengthening solutions. Seismic behavior of the selected models confirms results of previous work regarding the insufficient capacity of the open ground stories for design level earthquakes. It is also shown that strengthening only the weak ground story, a choice having the substantial advantage of low cost and continued usage of the building during its seismic retrofitting, can remove the inherent weakness without shifting the problem to the stories above and thus making such buildings at least as strong as those without a weak first story. This partial strengthening is possible for symmetric as well as eccentric buildings, in which torsion plays a further detrimental role.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.410-415
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• 2001

An analytical and numerical examination of second-order fractional-step methods and boundary condition for the incompressible Navier-Stokes equations is presented. In this study, the compatibility condition for pressure Poisson equation and its boundary conditions, stability, and numerical accuracy of canonical fractional-step methods has been investigated. It has been found that satisfaction of compatibility condition depends on tentative velocity and pressure boundary condition, and that the compatible boundary conditions for type D method and approximately compatible boundary conditions for type P method are proper for divergence-free velocity for type D and approximately divergence-free for type P method. Instability of canonical fractional-step methods is induced by approximation of implicit viscous term with explicit terms, and the stability criteria have been founded with simple model problems and numerical experiments of cavity flow and Taylor vortex flow. The numerical accuracy of canonical fractional-step methods with its consistent boundary conditions shows second-order accuracy except $D_{MM}$ condition, which make approximately first-order accuracy due to weak coupling of boundary conditions.

• Journal of The Korean Astronomical Society
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• v.53 no.3
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• pp.59-67
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• 2020

We propose semi-analytic models for the electron momentum distribution in weak shocks that accounts for both in situ acceleration and re-acceleration through diffusive shock acceleration (DSA). In the former case, a small fraction of incoming electrons is assumed to be reflected at the shock ramp and pre-accelerated to the so-called injection momentum, p_inj, above which particles can diffuse across the shock transition and participate in the DSA process. This leads to the DSA power-law distribution extending from the smallest momentum of reflected electrons, p_ref, all the way to the cutoff momentum, p_eq, constrained by radiative cooling. In the latter case, fossil electrons, specified by a power-law spectrum with a cutoff, are assumed to be re-accelerated from p_ref up to p_eq via DSA. We show that, in the in situ acceleration model, the amplitude of radio synchrotron emission depends strongly on the shock Mach number, whereas it varies rather weakly in the re-acceleration model. Considering the rather turbulent nature of shocks in the intracluster medium, such extreme dependence for the in situ acceleration might not be compatible with the relatively smooth surface brightness of observed radio relics.

• Journal of applied mathematics & informatics
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• v.35 no.1_2
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• pp.95-111
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• 2017

Recently, interval-valued fuzzy graph is a growing research topic as it is the generalization of fuzzy graphs. The interval-valued fuzzy graphs are more flexible and compatible than fuzzy graphs due to the fact that they allowed the degree of membership of a vertex to an edge to be represented by interval values in [0.1] rather than the crisp values between 0 and 1. In this paper, we introduce the concepts of regular and totally regular interval-valued fuzzy graphs and discusses some properties of the ${\mu}$-complement of interval-valued fuzzy graph. Self ${\mu}$-complementary interval-valued fuzzy graphs and self-weak ${\mu}$-complementary interval-valued fuzzy graphs are defined and a necessary condition for an interval valued fuzzy graph to be self ${\mu}$-complementary is discussed. We define busy vertices and free vertices in interval valued fuzzy graph and study their image under an isomorphism.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.219-226
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• 2013

Organic semiconductor-based soft electronics has potential advantages for next-generation electronics and displays, which request mobile convenience, flexibility, light-weight, large area, etc. Organic field-effect transistors (OFET) are core elements for soft electronic applications, such as e-paper, e-book, smart card, RFID tag, photovoltaics, portable computer, sensor, memory, etc. An optimal multi-layered structure of organic semiconductor, insulator, and electrodes is required to achieve high-performance OFET. Since most organic semiconductors are self-assembled structures with weak van der Waals forces during film formation, their crystalline structures and orientation are significantly affected by environmental conditions, specifically, substrate properties of surface energy and roughness, changing the corresponding OFET. Organo-compatible insulators and surface treatments can induce the crystal structure and orientation of solution- or vacuum-processable organic semiconductors preferential to the charge-carrier transport in OFET.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.1
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• pp.28-34
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• 2010

The pulse width modulation(PWM) method has been generally used as conventional method controlling luminance of LED(light emitting diode). PWM method as analog method with a relation that duty ratio of LED be proportional to luminance has weak point that it is not compatible with digital method of communication etc. In this paper, a experiment is conducted which the luminance of RGB LED be controlled by digital method. For this, the LED digital control system is developed which consist of LED driving circuits and digital logic circuits. By controlling the number of pluses on RGB LED versus digital input, various lighting colors is implemented and digital codes are optimized in order that measured x, y chromaticity coordinates of lighting colors are comprised in the CIE chromaticity coordinates area of targeted lighting colors. The result of this study can be utilized usefully in research on implementing full color by using remote control of LED lamp with digital communication.

• Journal of The Korean Society of Clinical Toxicology
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• v.4 no.2
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• pp.161-165
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• 2006

Organophosphate insecticides, commonly used in agriculture, are a gradually increasing cause of accidental and suicidal poisoning. Intoxication can occur by ingestion, inhalation or dermal contact. Exposure to organophosphorus agents causes a sequentially triphasic illness consisting of the cholinergic phase, the intermediate syndrome, and organophosphate-induced delayed polyneuropathy. Acute pancreatitis as a rare complication of organophosphate intoxication has also been infrequently observed. We report a case of intoxication with organophosphate (phos-phamidon) by parenteral exposure (inhalation and/or dermal contact). A 34-year-old male patient was transferred to our Emergency Medical Center and was intubated due to a progressive respiratory failure. He presented with meiotic pupils, cranial nerve palsies, weak respiration, and proximal limb motor weaknesses without sensory changes. He had been employed in filling syringes with phosphamidon during the previous month. Because the patient's history and symptoms suggested organophosphate intoxication with intermediate syndrome, he was mechanically ventilated for 18 days with continuous infusion of atropine and pralidoxime (total amounts of 159 mg and 216 g, respectively). During his admission, hyperamylasemia and hyperli-pasemia were detected, and his abdominal CT scan showed a finding compatible with acute pancreatitis. He was administered a conservative treatment with NPO and nasogastric drainage. The patient was discharged and showed neither gastrointestinal nor neurologic sequelae upon follow up at one week and three months.

• Korean Journal of Materials Research
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• v.20 no.5
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• pp.241-245
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• 2010

One of the weak points of the Cr-doped SZO is that until now, it has only been fabricated on perovskite substrates, whereas NiO-ReRAM devices have already been deposited on Si substrates. The fabrication of RAM devices on Si substrates is important for commercialization because conventional electronics are based mainly on silicon materials. Cr-doped ReRAM will find a wide range of applications in embedded systems or conventional memory device manufacturing processes if it can be fabricated on Si substrates. For application of the commercial memory device, Cr-doped $SrZrO_3$ perovskite thin films were deposited on a $SrRuO_3$ bottom electrode/Si(100)substrate using pulsed laser deposition. XRD peaks corresponding to the (112), (004) and (132) planes of both the SZO and SRO were observed with the highest intensity along the (112) direction. The positions of the SZO grains matched those of the SRO grains. A well-controlled interface between the $SrZrO_3$:Cr perovskite and the $SrRuO_3$ bottom electrode were fabricated, so that good resistive switching behavior was observed with an on/off ratio higher than $10^2$. A pulse test showed the switching behavior of the Pt/$SrZrO_3:Cr/SrRuO^3$ device under a pulse of 10 kHz for $10^4$ cycles. The resistive switching memory devices made of the Cr-doped $SrZrO_3$ thin films deposited on Si substrates are expected to be more compatible with conventional Si-based electronics.

• Journal of Chest Surgery
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• v.5 no.1
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• pp.13-18
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• 1972

In 1835,Schlesinger first described a case of subisthmlc lower thoracic aortic coarctation. Since Olim`s unsuccessful reconstructive surgery in 1949 and Beattie`s first successful resection with homograft replacement on such a lesion in 1951 were reported,about 20 cases of atypical aortic coarctation had been treated by definitive surgery until 1964. In Korea, only 2 cases of atypical aortic coarctation treated by bypass graft were reported until now. This is the third case-report treated by reconstructive surgery. The patient,11 year old girl who had 2 year history of headache, visual weakness, intermittent claudlcation, and general weakness, was first diagnosed of having the hypertension due to atypical coarctation by the findings of high blood pressure[170/110mmHg] at the upper extremity and weak pulsation on both femoral artery,murmur on the epigastrium, absence of aortic knob, and aorto graphy. Aortography demonstrated the isolated segmental narrowing[length 5cm, diameter 0.4cm] at the level of aortic hiatus 2cm above celiac arterial origin, the dilated right 9th, 10th, 11th intercostal arteries with multiple dimunitive collaterals and no associated abnormalities in the other arteries. Preoperatlve positive findings were strong positive mantoux test, high AST[720 units]. transient mild cardiomegaly with right lung infiltration on chest X-ray and suggestive left ventricular hypertrophy on ECG. On December 1970, through separate left thoracotomy and abdominal approach, bypass graft between descending thoracic aorta and abdominal aorta below renal artery was performed. The operation was first successful with satisfactory reduction of hypertension on the upper trunk[postoperatlve 130/80mmHg] and strong pulsation on the lower extremities[postop. O, postop. 140/100mmHg]. However,6 weeks after surgery, she expired of sudden hemoptysis and shock due to anastomotic leak within the thorax. Operative finding disclosed that the affected aorta was firm, with rich periaortic fibrosis and the outer diameter of stenotic site was not attenuated. Histopathology of the resected specimen was also compatible with primary arteritis.

• Structural Engineering and Mechanics
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• v.85 no.6
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• pp.793-808
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• 2023

Türkiye is located in a region where destructive earthquakes are frequently experienced due to its geological characteristics and geographical location. Therefore, considering the possibility of a devastating earthquake at any time, determining the reinforced concrete (RC) building seismic safety, constructed before or after the current seismic buildings code, is one of the most important issues to be completed firstly. For this purpose, rapid assessment methods developed to quickly determine the seismic safety of buildings are available in the literature. Comparison of the principles of Principles of the Determination of Risky Structures-2019, Column and Wall Index Method, P25 Scoring Method and Improved Discriminant Analysis Method, which are among these methods, have been aimed within the scope of this study. Within the scope of this paper, a total of 43 buildings in the Yalova/Çınarcık region of Türkiye that the damage level was determined by street observation method immediately after the 1999 Kocaeli (Izmit) Earthquake; 15 buildings with heavy damage and 28 buildings with moderate damage were examined by rapid assessment methods. Although the risk detection difference was not separated as a clear line in any of the methods used, the results obtained from the rapid assessment methods are evaluated as being compatible with the detected after earthquake structural seismic behavior of the buildings. The PDRS-2019 and column and wall index method gave the most approximate results. In the results obtained from the analyzes; structural features such as number of floors, frame continuity, soft/weak story irregularity, effective shear strength area, existence of heavy overhangs in plan, type of structural system have been found to be significantly effective on the earthquake behavior of buildings.