• Wind and Structures
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• v.37 no.1
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• pp.15-23
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• 2023

The wake behavior of extended flat plate and serration in the trailing edge of S809 airfoil is presented in this experimental study using wind tunnel testing. The clustering of wind turbines in wind parks has recently been a pressing issue, due to the expected increase in power output and deciding the number of wind turbines to be installed. One of the prominent factors which influence the performance of the subsequent wind turbines is the downstream wake characteristics. A series of wind tunnel investigations were performed to assess the downstream near wake characteristics of the S809 airfoil at various angles of attack corresponding to the Reynolds Number Re = 2.02 × 105. These experimental results revealed the complex nature of the downstream near wake characteristics featuring substantial asymmetry arising out of the incoherent flow separations prevailing over the suction and the pressure sides of the airfoil. Based on the experimental results, it is found that the wake width and the downstream velocity ratio decrease with an increase in the angle of attack. Nonetheless, the dissipation length and downstream velocity ratio increases proportionally in the downstream direction. Additionally, attempts were made to understand the physical nature of the near wake characteristics at 1C, 2C, 3C and 4C downstream locations.

• Journal of Arbitration Studies
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• v.33 no.3
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• pp.147-175
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• 2023

The emergence of the metaverse, a complex three-dimensional virtual environment, has led to significant changes in the intellectual property (IP) landscape. This paper examines the challenges and legal intricacies of IP within the virtual realm, focusing on the unprecedented nature of these disputes and on the inadequacies of traditional jurisdiction methods. Drawing from international frameworks, including the International Law Association's Guidelines and WIPO's guides, the study critically explores arbitration as an alternate approach to metaverse IP disputes, analyzing its complexities and applicability. The paper further delves into challenges arising from diverse protection laws that pertain to the global nature of the metaverse, including the nuances of various digital assets like NFTs. By assessing jurisdictional difficulties, the paper addresses the adoption of decentralized justice platforms, and examines the role of Alternative Dispute Resolution (ADR) methods, this paper presents a comprehensive view of the evolving virtual legal field. It suggests that while innovative methods are emerging, traditional arbitration will likely remain the preferred choice for complex disputes, offering a balance of speed, cost-effectiveness, and legal robustness within the virtual world.

• Journal of the Korean Society for Nondestructive Testing
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• v.9 no.1
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• pp.22-29
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• 1989

The important point of MPI is the analysis of leakage field in the defective regions. The analysis of leakage field depends on many factors such like geometry and character of defect. In general the calculation of magnetic leakage fields arising from such defects presents an extremely complicated mathematical problem and is practically insoluable, since the inhomogeneities have complex geometrical shapes and may differ in physical nature. Therefore, this paper describes Hall probe measurements of residual leakage field around artificial flaws in alloy steel bar, and shows how the results to recent developments in 2D dipole and analytic models of the magnetic field defect interaction.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.143-150
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• 2004

An optimum design problem for endosseous implant in dentistry is studied to find best implant design. An optimum design problem is formulated to reduce stresses arising at the cortical as well as cancellous bones, in which sufficient design parameters are chosen for design definition that encompasses major implants in popular use. Optimization at once (OAO) with the large number of design variables, however, causes too costly solution or even failure to converge. A concept of multilevel optimization (MLO) is employed to this end, which is to group the design variables of similar nature, solve the sub-problem of smaller size for each group in sequence, and this is iterated until convergence. Each sub-problem is solved based on the response surface method (RSM) due to its efficiency for small sized problem.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.221-231
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• 1995

This paper proposes that a GDSS research boundary needs to be further expanded to include more human-nature variables arising in natural group interaction processes. By doing so, we can better understand the GDSS phenomena and have a better picture for designing effective GDSS for group decisions. Specifically, this paper reviewed literature and explored variables to be further included in GDSS research arena. As results, this paper proposed an extended framework for GDSS research that includes variables that have been little considered in most empirical studies to date. Then, the variables and their relationships are used to explain the handicaps of current GDSS uses and to redirect the ways of utilizing GDSS technologies for group decision-making. Based on the framework, we suggested proposititions for the future research.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.56-61
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• 1986

Rotor dynamic response of pumps is greatly influenced by the nature of the hydraulic forces arising from wearing seal, balance drum and impeller, etc.. Therefore, rotor dynamic analysis should be conducted during the design stage in order to aleviate some of the vibrational problems which might occur during the operational life of pumps. Previsousely, the authors have proposed the method to obtain the dynamic seal coefficients of the annular plain seal, convergent and divergent tapered seals, parallel grooved seal, spiral grooved seal and annular stepped seal. On the basis of these results, this paper presents the investigated effect of seals on the stability behavior of a centrifugal pump. The results show the effects of seal geometry, pressure difference, clearance, length/diameter ratio, on stability behavior.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.7
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• pp.940-947
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• 2004

In this paper, an optimum design problem for endosseous implant in dentistry is studied to find best implant design. An optimum design problem is formulated to reduce stresses arising at the cortical as well as cancellous bones, in which sufficient design parameters are chosen for design definition that encompasses major implants in popular use. Optimization at once (OAO) with the large number of design variables, however, causes too costly solution or even failure to converge. A concept of multilevel optimization (MLO) is employed to this end, which is to group the design variables of similar nature, solve the sub-problem of smaller size for each group in sequence, and this is iterated until convergence. Each sub-problem is solved based on the response surface method (RSM) due to its efficiency for small sized problem.

• Clinics in Shoulder and Elbow
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• v.21 no.3
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• pp.158-161
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• 2018

Hereditary multiple exostosis (HME) is an autosomal dominant disorder manifested by the presence of multiple osteochondromas. Although the lesions are benign in nature, exostoses are often associated with characteristic progressive skeletal deformity and displaying clinical symptoms such as mechanical irritation or impingement. We present the successful arthroscopic resection in a 24-year-old HME male with impingement syndrome and long head tendon tear of the biceps caused by osteochondroma arising from the distal clavicle.

• Journal of Chest Surgery
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• v.13 no.1
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• pp.48-51
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• 1980

Open heart surgery patients have additional risks arising from the special nature of the operative procedure. And postoperative infections in patients with extracorporeal circulation are associated with high incidence of serious sequelae. To investigate the incidence and organisms of contamination, and the relation between the duration of extracorporeal circulation and contamination, following study was done. Eighty-four of the open heart surgery patients were examined with cultures from the blood and priming solution before and after bypass. 1. Cultures before bypass were sterile, but 2 cases of cultures from the blood and priming solution after bypass were positive, and culture positive group was 5% of all patients. 2. The organisms were Gram-negative, aerobic coliform bacilli; 3. The culture positive group had significantly longer bypass time.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.234-239
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• 2004

Recently, the tunnel structures are increasing. And the tunnels are to be large diameter tunnel and long. Therefore, inspection, repair, and maintenance of tunnels are an extremely important part of infrastructure management, with particular technical and safety considerations arising from the very nature of underground construction. To inspect surface state of tunnels, concrete structures, it must generally use method of conventional visual inspection, but this method is very not objective. To measure the width, length, position, direction of a crack, it is very difficult, when the tunnel is long span and high rise. Thus, to make up for this demerits, in this paper is proposed the Tunnel Scanning System that we can check conditions of the tunnel structures quickly, detect the detailed data objectively, count automatically the width of a crack by the original software and follow the trend of long tenn changes in the condition of a tunnel.