Yonsei University

About: Yonsei University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Cancer. The organization has 50162 authors who have published 106172 publications receiving 2279044 citations. The organization is also known as: Yonsei.

M2M Service Platforms: Survey, Issues, and Enabling Technologies

Abstract: Machine-to-Machine (M2M) refers to technologies with various applications. In order to provide the vision and goals of M2M, an M2M ecosystem with a service platform must be established by the key players in industrial domains so as to substantially reduce development costs and improve time to market of M2M devices and services. The service platform must be supported by M2M enabling technologies and standardization. In this paper, we present a survey of existing M2M service platforms and explore the various research issues and challenges involved in enabling an M2M service platform. We first classify M2M nodes according to their characteristics and required functions, and we then highlight the features of M2M traffic. With these in mind, we discuss the necessity of M2M platforms. By comparing and analyzing the existing approaches and solutions of M2M platforms, we identify the requirements and functionalities of the ideal M2M service platform. Based on these, we propose an M2M service platform (M2SP) architecture and its functionalities, and present the M2M ecosystem with this platform. Different application scenarios are given to illustrate the interaction between the components of the proposed platform. In addition, we discuss the issues and challenges of enabling technologies and standardization activities, and outline future research directions for the M2M network.

Shape evolution of single-crystalline iron oxide nanocrystals.

Abstract: Shape- and size-controlled synthesis of single-crystalline maghemite (γ-Fe2O3) nanocrystals are performed by utilizing a solution-based one-step thermolysis method. Modulating the growth parameters, such as the type and amount of capping ligands as well as the growth time, is shown to have a significant effect on the overall shape and size of the obtained nanocrystals and on the ripening process itself. The resulting shapes of the novel structures are diverse, including slightly faceted spheres, diamonds, prisms, and hexagons, all of which are in fact truncated dodecahedron structures with different degrees of truncation along the {111}, {110}, or {100} faces. Spherical nanocrystals are easily assembled into the three-dimensional superlattices, demonstrating the uniformity of these nanocrystals. The size-dependent magnetic properties are examined, and large hexagon-shaped γ-Fe2O3 nanocrystals are shown to be ferrimagnetic at room temperature.

Coronary artery anomalies: classification and ECG-gated multi-detector row CT findings with angiographic correlation.

Abstract: Congenital abnormalities of the coronary arteries are an uncommon but important cause of chest pain and, in some cases of hemodynamically significant abnormalities, sudden cardiac death. For several decades, premorbid diagnosis of coronary artery anomalies has been made with conventional angiography. However, this imaging technique has limitations due to its projectional and invasive nature. The recent development of electrocardiographically (ECG)-gated multi-detector row computed tomography (CT) allows accurate and noninvasive depiction of coronary artery anomalies of origin, course, and termination. Multi-detector row CT is superior to conventional angiography in delineating the ostial origin and proximal path of an anomalous coronary artery. Familiarity with the CT appearances of various coronary artery anomalies and an understanding of the clinical significance of these anomalies are essential in making a correct diagnosis and planning patient treatment.