• Nuclear Engineering and Technology
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• v.52 no.9
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• pp.2119-2129
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• 2020

Flow-accelerated corrosion (FAC), liquid droplet impingement erosion (LDIE), cavitation and flashing can cause continuous wall-thinning in nuclear secondary pipes. In order to prevent pipe rupture events resulting from the wall-thinning, most NPPs (nuclear power plants) implement their management programs, which include periodic thickness inspection using UT (ultrasonic test). Meanwhile, it is well known in field experiences that the thickness measurement errors (or deviations) are often comparable with the amount of thickness reduction. Because of these errors, it is difficult to estimate wall-thinning exactly whether the significant thinning has occurred in the inspected components or not. In the previous study, the authors presented an approximate estimation procedure as the first step for thickness measurement deviations at each inspected component and the statistical & quantitative characteristics of the measurement deviations using plant experience data. In this study, statistical significance was quantified for the current methods used for wall-thinning determination. Also, the authors proposed new estimation procedures for determining local wall-thinning to overcome the weakness of the current methods, in which the proposed procedure is based on analysis of variance (ANOVA) method using subgrouping of measured thinning values at all measurement grids. The new procedures were also quantified for their statistical significance. As the results, it is confirmed that the new methods have better estimation confidence than the methods having used until now.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.353-359
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• 2022

Several suture patterns can be used for cystotomy closure, and a continuous suture pattern is the most commonly used. In this study, the fluid-tight ability and other suitabilities of continuous appositional sutures, such as the simple continuous suture pattern (SC), running suture pattern (RN), and Ford interlocking suture pattern (FI), were compared for cystotomy closure. Cystotomy closure was performed using each suture method in 10 cases of ex vivo swine bladders in each group. Suture time, leakage site, suture length, bursting pressure (BP), bursting volume (BV), and circular bursting wall tension (CBWT) were measured. Suture time and suture length were the shortest in RN and the longest in FI. Leakage occurred in two places: the incision line directly and the hole made by the suture. Leakage occurred through the incision line in 4 bladders of the RN group and 2 bladders of the FI group, but not in the SC group, and in the rest of the bladders, leakage occurred through the suture hole. The values of BP, BV, and CBWT increased in the order of FI, SC, and RN. Suture time and suture length can be considered as factors related to healing and side effects. In this study, leakage through the incision was found in a less appositional area; therefore, leakage through the hole could be considered an indicator of better apposition. Good apposition is one of the conditions required for ideal cystotomy closure. The bursting strength representing the fluid-tight ability can be expressed as the CBWT. RN is expected to be efficient and cause a small degree of foreign body reaction; however, it is expected to be less stable. FI has the greatest fluid-tightness ability, but it has been proposed that side effects due to foreign body reactions most frequently occur in FI. In conclusion, SC, which is expected to have a sufficient degree of fluid-tightness and appropriate recovery, is preferable to other continuous appositional suturing methods for cystotomy closure.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.12
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• pp.967-972
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• 2001

In this paper, an adaptive robust nonlinear predictive controller is developed for the continuous time nonlinear systems whose control objective is composed of the system output and its desired value. The basic control law is derived from the continuous time prediction model and its feedback dynamcis shows another from if input and output linearization. In order to cope with the parameter uncertainty, robust control is incorporated into the basic control law and the asymptotic convergence of tracking error to a certain bounded region is guaranteed. For stability and performance improvement within the bounded region, an adaptive control is introduced. Simulation tests for the motion control of an underwater wall-ranging robot confirm the performance improvement and the robustness of this controller.

• Korean Journal of Materials Research
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• v.19 no.9
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• pp.473-480
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• 2009

In order to provide the mechanism of nozzle clogging, recovered nozzles for high strength steel grade were examined carefully after continuous casting. The thickness of clogged material in SEN is increased in the following order: from the bottom to the top of the nozzle, upper part of slag line, and the pouring hole. Nozzle clogging material begins to form due the adhesion of metal to nozzle wall, the decarburization, and reduction of oxide in the refractory by Al and Ti in the melt. The reduction of oxide in the refractory by Al and Ti improves the wettability of the melt on the refractory and forms a thin Al-Ti-O layer. Metal containing micro alumina inclusions is solidified on the Al-Ti-O layer, and the solid layer grows due to the heat evolution through the nozzle wall. Thermodynamic calculation has been made for the related reactions. The effect of superheat to the nozzle clogging is discussed on ultra low carbon steel and low carbon steel.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.12
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• pp.1236-1244
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• 2001

In the present study, the possibility of continuous slurry ice making using flowing water solution in a cooled tube has been investigated. The experiments were carried out at various concentration and velocity of water solution, temperature of cooled tube wall, and control pressure in a tube. As a result, four types of operating conditions, that is super-cooling, continuous ice making, intermittent ice making and ice blockage, were classified. And it was found that the critical condition for the continuous ice making was acquired as a function of these experimental parameters.

• Earthquakes and Structures
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• v.16 no.1
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• pp.83-96
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• 2019

The seismic behavior of PRC coupling beam-hybrid coupled shear wall system is analyzed by using the finite element software ABAQUS. The stress distribution of steel plate, reinforcing bar in coupling beam, reinforcing bar in slab and concrete is investigated. Meanwhile, the plastic hinges developing law of this hybrid coupled shear wall system is also studied. Further, the effect of coupling ratio, section dimensions of coupling beam, aspect ratio of single shear wall, total height of structure and the role of slab on the seismic behavior of the new structural system. A fitting formula of plate characteristic values for PRC coupling beams based on different displacement requirements is proposed through the experimental date regression analysis of PRC coupling beams at home and abroad. The seismic behavior control method for PRC coupling beam-hybrid coupled shear wall system is proposed based on the continuous connection method and through controlling the coupling ratio, the roof displacement, story drift angle of hybrid coupled shear wall system, displacement ductility of coupling beam.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.118-123
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• 2023

With the continuous development of emerging technologies represented by VR technology, many game developers are declaring that they are constantly trying to break the "fourth wall" and break the boundaries between virtual and reality to create game immersion for players. new game. But for many gamers, a strong sense of immersion is not the focus of their pursuit. The sense of control and safe exploration during the game is also the game experience that many gamers are pursuing. Moreover, there is ambiguity in the definition of the concept of breaking the fourth wall in the field of academic theory. The purpose of breaking the fourth wall was to separate the real world from the virtual world, to remind the audience that the actors and the audience are in two different worlds, and to trigger the audience's thinking about drama and deeper philosophy. But in the current game, it has become a blurring of the boundary between virtual and reality, pulling players into the virtual world, and focusing on the immersive experience. In this paper, we will first sort out the concept of "breaking the fourth wall", and then conduct a comparative analysis of horizontal scroll games and VR games, and conclude that the "fourth wall" has an impact on players Great conclusion.

• Journal of architectural history
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• v.19 no.6
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• pp.121-135
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• 2010

This study was to analyze the architectural characteristics and facade construction of brick masonry auditorium through the Auditorium of Namsan Primary School in 1936. The results of this study were described separately as follows. 1. The auditorium is located away from the school buildings, and its plane is a chamber of rectangle type with an entrance installed on each of the four sides. 2. The external appearance is Renaissance eclectic style, laid red bricks on the lower wall of the window and having a mansard roof. The front and the rear are symmetric with respect to the projected wall at the center. 3. As to the structure of the building, a concrete lower wall was built on the concrete continuous footing, and the brick wall was constructed on the lower wall. The roof is queen post roof truss, and the wall girders were installed on the brick wall. 4. The auditorium has had a number of repairing and maintenance works, which changed the roof and windows outside and the floor, walls, ceiling, etc. inside. 5. The decorative elements of external appearance include lower wall, brick wall, entrances, windows, roof, and dormer windows. The brick wall gives verticality and solidity to the surface of the wall, and the lower wall and wall girders are connected like a cornice of the wall. The surface of the mansard roof and dormer windows express a stable vertically oriented shape.

• Biomedical Science Letters
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• v.13 no.2
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• pp.111-117
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• 2007

Temporary occlusion of the parent artery or feeding artery is an useful method in microsurgery for cerebrovascular diseases. The advantages of the temporary clipping for intracranial aneurysm surgery have already been proven by many experimental and clinical reports. Currently, there are two methods of temporary clipping: 1) intermittent clipping, 2) continuous clipping. In many previous studies, the intermittent, repeated clipping technique was reported to reduce ischemic damage to the brain, but it is still debated. On the other hand, a comparison of the histological changes on the arterial wall between each clipping method has not been sufficiently reported yet. So the authors performed experimental temporary clipping on the common carotid and femoral arteries of about 25 rats using the Sugita temporary mini-clip. The specimens were divided into two major groups and seven subgroups: Group I (I-1, I-2, I-3, I-4, intermittent clippings for 5 minutes were done once, twice, three times, and few times), and Group C (C-10, C-15, C-20, continuous clippings for 10, 15, 20 minutes, respectively). The reperfusion time after the temporary clipping was the same as the clipping duration. Under light microscope, the histological findings by Hematoxylin-Eosin staining were examined in all specimens, which were obtained at each time interval after temporary clipping. Then the histological changes of the arterial walls by two different methods were compared with the normal specimen. The results suggest that intermittent temporary clipping is less damaging on the arterial wall than single continuous clipping.

• Journal of Chest Surgery
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• v.6 no.1
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• pp.51-56
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• 1973

This is one case report of successful resection of the aneurysm of the thoracic aorta, which det-ected by thoractomy unexpectedly, in the Department of Thoracic Surgery, Hanyang University Hospital. The patient was a 34 years old woman and subjective complaints was not related with the aneurysm. Chest film showed a small round hazy shadow in the left margin of the upper posterior mediastinum. A saccular aneurysm located on the descending thoracic aorta, 7cm distal to the left subclavian artery and arouse from the antero-lateral wall of the aorta. Excision of the saccular aneurysm was performed by cross clamping the descending aorta above and below the aneurysm, and then the defect of the aortic wall was closed by aortorrhaphy with continuous suture. Crossclamping time was required 15 minute. Histopathologically, the wall of the aneurysm consisted of all layers of the arterial wall, that is, intima, media and adventitia. Postoperative course was uneventful and aortogram showed good continuity of the blood flow of the entire aorta.